http://git-wip-us.apache.org/repos/asf/commons-text/blob/4b67dd51/src/main/java/org/apache/commons/text/StringSubstitutor.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/text/StringSubstitutor.java b/src/main/java/org/apache/commons/text/StringSubstitutor.java new file mode 100644 index 0000000..583cd37 --- /dev/null +++ b/src/main/java/org/apache/commons/text/StringSubstitutor.java @@ -0,0 +1,1359 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.commons.text; + +import java.util.ArrayList; +import java.util.Enumeration; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.Properties; + +import org.apache.commons.lang3.Validate; +import org.apache.commons.text.lookup.StringLookup; +import org.apache.commons.text.lookup.StringLookupFactory; +import org.apache.commons.text.matcher.StringMatcher; +import org.apache.commons.text.matcher.StringMatcherFactory; + +/** + * Substitutes variables within a string by values. + * <p> + * This class takes a piece of text and substitutes all the variables within it. The default definition of a variable is + * <code>${variableName}</code>. The prefix and suffix can be changed via constructors and set methods. + * <p> + * Variable values are typically resolved from a map, but could also be resolved from system properties, or by supplying + * a custom variable resolver. + * <p> + * The simplest example is to use this class to replace Java System properties. For example: + * + * <pre> + * StrSubstitutor + * .replaceSystemProperties("You are running with java.version = ${java.version} and os.name = ${os.name}."); + * </pre> + * <p> + * Typical usage of this class follows the following pattern: First an instance is created and initialized with the map + * that contains the values for the available variables. If a prefix and/or suffix for variables should be used other + * than the default ones, the appropriate settings can be performed. After that the <code>replace()</code> method can be + * called passing in the source text for interpolation. In the returned text all variable references (as long as their + * values are known) will be resolved. The following example demonstrates this: + * + * <pre> + * Map valuesMap = HashMap(); + * valuesMap.put("animal", "quick brown fox"); + * valuesMap.put("target", "lazy dog"); + * String templateString = "The ${animal} jumped over the ${target}."; + * StrSubstitutor sub = new StrSubstitutor(valuesMap); + * String resolvedString = sub.replace(templateString); + * </pre> + * + * yielding: + * + * <pre> + * The quick brown fox jumped over the lazy dog. + * </pre> + * <p> + * Also, this class allows to set a default value for unresolved variables. The default value for a variable can be + * appended to the variable name after the variable default value delimiter. The default value of the variable default + * value delimiter is ':-', as in bash and other *nix shells, as those are arguably where the default ${} delimiter set + * originated. The variable default value delimiter can be manually set by calling + * {@link #setValueDelimiterMatcher(StringMatcher)}, {@link #setValueDelimiter(char)} or + * {@link #setValueDelimiter(String)}. The following shows an example with variable default value settings: + * + * <pre> + * Map valuesMap = HashMap(); + * valuesMap.put("animal", "quick brown fox"); + * valuesMap.put("target", "lazy dog"); + * String templateString = "The ${animal} jumped over the ${target}. ${undefined.number:-1234567890}."; + * StrSubstitutor sub = new StrSubstitutor(valuesMap); + * String resolvedString = sub.replace(templateString); + * </pre> + * + * yielding: + * + * <pre> + * The quick brown fox jumped over the lazy dog. 1234567890. + * </pre> + * <p> + * In addition to this usage pattern there are some static convenience methods that cover the most common use cases. + * These methods can be used without the need of manually creating an instance. However if multiple replace operations + * are to be performed, creating and reusing an instance of this class will be more efficient. + * <p> + * Variable replacement works in a recursive way. Thus, if a variable value contains a variable then that variable will + * also be replaced. Cyclic replacements are detected and will cause an exception to be thrown. + * <p> + * Sometimes the interpolation's result must contain a variable prefix. As an example take the following source text: + * + * <pre> + * The variable ${${name}} must be used. + * </pre> + * + * Here only the variable's name referred to in the text should be replaced resulting in the text (assuming that the + * value of the <code>name</code> variable is <code>x</code>): + * + * <pre> + * The variable ${x} must be used. + * </pre> + * + * To achieve this effect there are two possibilities: Either set a different prefix and suffix for variables which do + * not conflict with the result text you want to produce. The other possibility is to use the escape character, by + * default '$'. If this character is placed before a variable reference, this reference is ignored and won't be + * replaced. For example: + * + * <pre> + * The variable $${${name}} must be used. + * </pre> + * <p> + * In some complex scenarios you might even want to perform substitution in the names of variables, for instance + * + * <pre> + * ${jre-${java.specification.version}} + * </pre> + * + * <code>StrSubstitutor</code> supports this recursive substitution in variable names, but it has to be enabled + * explicitly by setting the {@link #setEnableSubstitutionInVariables(boolean) enableSubstitutionInVariables} property + * to <b>true</b>. + * <p> + * This class is <b>not</b> thread safe. + * </p> + * + * @since 1.3 + */ +public class StringSubstitutor { + + /** + * Constant for the default escape character. + */ + public static final char DEFAULT_ESCAPE = '$'; + + /** + * Constant for the default variable prefix. + */ + public static final StringMatcher DEFAULT_PREFIX = StringMatcherFactory.INSTANCE.stringMatcher("${"); + + /** + * Constant for the default variable suffix. + */ + public static final StringMatcher DEFAULT_SUFFIX = StringMatcherFactory.INSTANCE.stringMatcher("}"); + + /** + * Constant for the default value delimiter of a variable. + */ + public static final StringMatcher DEFAULT_VALUE_DELIMITER = StringMatcherFactory.INSTANCE.stringMatcher(":-"); + + // ----------------------------------------------------------------------- + /** + * Replaces all the occurrences of variables in the given source object with their matching values from the map. + * + * @param <V> + * the type of the values in the map + * @param source + * the source text containing the variables to substitute, null returns null + * @param valueMap + * the map with the values, may be null + * @return the result of the replace operation + */ + public static <V> String replace(final Object source, final Map<String, V> valueMap) { + return new StringSubstitutor(valueMap).replace(source); + } + + /** + * Replaces all the occurrences of variables in the given source object with their matching values from the map. + * This method allows to specify a custom variable prefix and suffix + * + * @param <V> + * the type of the values in the map + * @param source + * the source text containing the variables to substitute, null returns null + * @param valueMap + * the map with the values, may be null + * @param prefix + * the prefix of variables, not null + * @param suffix + * the suffix of variables, not null + * @return the result of the replace operation + * @throws IllegalArgumentException + * if the prefix or suffix is null + */ + public static <V> String replace(final Object source, final Map<String, V> valueMap, final String prefix, + final String suffix) { + return new StringSubstitutor(valueMap, prefix, suffix).replace(source); + } + + /** + * Replaces all the occurrences of variables in the given source object with their matching values from the + * properties. + * + * @param source + * the source text containing the variables to substitute, null returns null + * @param valueProperties + * the properties with values, may be null + * @return the result of the replace operation + */ + public static String replace(final Object source, final Properties valueProperties) { + if (valueProperties == null) { + return source.toString(); + } + final Map<String, String> valueMap = new HashMap<>(); + final Enumeration<?> propNames = valueProperties.propertyNames(); + while (propNames.hasMoreElements()) { + final String propName = (String) propNames.nextElement(); + final String propValue = valueProperties.getProperty(propName); + valueMap.put(propName, propValue); + } + return StringSubstitutor.replace(source, valueMap); + } + + /** + * Replaces all the occurrences of variables in the given source object with their matching values from the system + * properties. + * + * @param source + * the source text containing the variables to substitute, null returns null + * @return the result of the replace operation + */ + public static String replaceSystemProperties(final Object source) { + return new StringSubstitutor(StringLookupFactory.INSTANCE.systemPropertyStringLookup()).replace(source); + } + + /** + * Stores the escape character. + */ + private char escapeChar; + + /** + * Stores the variable prefix. + */ + private StringMatcher prefixMatcher; + + /** + * Stores the variable suffix. + */ + private StringMatcher suffixMatcher; + + /** + * Stores the default variable value delimiter. + */ + private StringMatcher valueDelimiterMatcher; + + /** + * Variable resolution is delegated to an implementor of {@link StringLookup}. + */ + private StringLookup variableResolver; + + /** + * The flag whether substitution in variable names is enabled. + */ + private boolean enableSubstitutionInVariables; + + /** + * Whether escapes should be preserved. Default is false; + */ + private boolean preserveEscapes = false; + + /** + * The flag whether substitution in variable values is disabled. + */ + private boolean disableSubstitutionInValues; + + // ----------------------------------------------------------------------- + /** + * Creates a new instance with defaults for variable prefix and suffix and the escaping character. + */ + public StringSubstitutor() { + this((StringLookup) null, DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_ESCAPE); + } + + /** + * Creates a new instance and initializes it. Uses defaults for variable prefix and suffix and the escaping + * character. + * + * @param <V> + * the type of the values in the map + * @param valueMap + * the map with the variables' values, may be null + */ + public <V> StringSubstitutor(final Map<String, V> valueMap) { + this(StringLookupFactory.INSTANCE.mapStringLookup(valueMap), DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_ESCAPE); + } + + /** + * Creates a new instance and initializes it. Uses a default escaping character. + * + * @param <V> + * the type of the values in the map + * @param valueMap + * the map with the variables' values, may be null + * @param prefix + * the prefix for variables, not null + * @param suffix + * the suffix for variables, not null + * @throws IllegalArgumentException + * if the prefix or suffix is null + */ + public <V> StringSubstitutor(final Map<String, V> valueMap, final String prefix, final String suffix) { + this(StringLookupFactory.INSTANCE.mapStringLookup(valueMap), prefix, suffix, DEFAULT_ESCAPE); + } + + /** + * Creates a new instance and initializes it. + * + * @param <V> + * the type of the values in the map + * @param valueMap + * the map with the variables' values, may be null + * @param prefix + * the prefix for variables, not null + * @param suffix + * the suffix for variables, not null + * @param escape + * the escape character + * @throws IllegalArgumentException + * if the prefix or suffix is null + */ + public <V> StringSubstitutor(final Map<String, V> valueMap, final String prefix, final String suffix, + final char escape) { + this(StringLookupFactory.INSTANCE.mapStringLookup(valueMap), prefix, suffix, escape); + } + + /** + * Creates a new instance and initializes it. + * + * @param <V> + * the type of the values in the map + * @param valueMap + * the map with the variables' values, may be null + * @param prefix + * the prefix for variables, not null + * @param suffix + * the suffix for variables, not null + * @param escape + * the escape character + * @param valueDelimiter + * the variable default value delimiter, may be null + * @throws IllegalArgumentException + * if the prefix or suffix is null + */ + public <V> StringSubstitutor(final Map<String, V> valueMap, final String prefix, final String suffix, + final char escape, final String valueDelimiter) { + this(StringLookupFactory.INSTANCE.mapStringLookup(valueMap), prefix, suffix, escape, valueDelimiter); + } + + /** + * Creates a new instance and initializes it. + * + * @param variableResolver + * the variable resolver, may be null + */ + public StringSubstitutor(final StringLookup variableResolver) { + this(variableResolver, DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_ESCAPE); + } + + /** + * Creates a new instance and initializes it. + * + * @param variableResolver + * the variable resolver, may be null + * @param prefix + * the prefix for variables, not null + * @param suffix + * the suffix for variables, not null + * @param escape + * the escape character + * @throws IllegalArgumentException + * if the prefix or suffix is null + */ + public StringSubstitutor(final StringLookup variableResolver, final String prefix, final String suffix, + final char escape) { + this.setVariableResolver(variableResolver); + this.setVariablePrefix(prefix); + this.setVariableSuffix(suffix); + this.setEscapeChar(escape); + this.setValueDelimiterMatcher(DEFAULT_VALUE_DELIMITER); + } + + /** + * Creates a new instance and initializes it. + * + * @param variableResolver + * the variable resolver, may be null + * @param prefix + * the prefix for variables, not null + * @param suffix + * the suffix for variables, not null + * @param escape + * the escape character + * @param valueDelimiter + * the variable default value delimiter string, may be null + * @throws IllegalArgumentException + * if the prefix or suffix is null + */ + public StringSubstitutor(final StringLookup variableResolver, final String prefix, final String suffix, + final char escape, final String valueDelimiter) { + this.setVariableResolver(variableResolver); + this.setVariablePrefix(prefix); + this.setVariableSuffix(suffix); + this.setEscapeChar(escape); + this.setValueDelimiter(valueDelimiter); + } + + /** + * Creates a new instance and initializes it. + * + * @param variableResolver + * the variable resolver, may be null + * @param prefixMatcher + * the prefix for variables, not null + * @param suffixMatcher + * the suffix for variables, not null + * @param escape + * the escape character + * @throws IllegalArgumentException + * if the prefix or suffix is null + */ + public StringSubstitutor(final StringLookup variableResolver, final StringMatcher prefixMatcher, + final StringMatcher suffixMatcher, final char escape) { + this(variableResolver, prefixMatcher, suffixMatcher, escape, DEFAULT_VALUE_DELIMITER); + } + + /** + * Creates a new instance and initializes it. + * + * @param variableResolver + * the variable resolver, may be null + * @param prefixMatcher + * the prefix for variables, not null + * @param suffixMatcher + * the suffix for variables, not null + * @param escape + * the escape character + * @param valueDelimiterMatcher + * the variable default value delimiter matcher, may be null + * @throws IllegalArgumentException + * if the prefix or suffix is null + */ + public StringSubstitutor(final StringLookup variableResolver, final StringMatcher prefixMatcher, + final StringMatcher suffixMatcher, final char escape, final StringMatcher valueDelimiterMatcher) { + this.setVariableResolver(variableResolver); + this.setVariablePrefixMatcher(prefixMatcher); + this.setVariableSuffixMatcher(suffixMatcher); + this.setEscapeChar(escape); + this.setValueDelimiterMatcher(valueDelimiterMatcher); + } + + /** + * Checks if the specified variable is already in the stack (list) of variables. + * + * @param varName + * the variable name to check + * @param priorVariables + * the list of prior variables + */ + private void checkCyclicSubstitution(final String varName, final List<String> priorVariables) { + if (!priorVariables.contains(varName)) { + return; + } + final StrBuilder buf = new StrBuilder(256); + buf.append("Infinite loop in property interpolation of "); + buf.append(priorVariables.remove(0)); + buf.append(": "); + buf.appendWithSeparators(priorVariables, "->"); + throw new IllegalStateException(buf.toString()); + } + + // Escape + // ----------------------------------------------------------------------- + /** + * Returns the escape character. + * + * @return the character used for escaping variable references + */ + public char getEscapeChar() { + return this.escapeChar; + } + + // Resolver + // ----------------------------------------------------------------------- + /** + * Gets the StringLookup that is used to lookup variables. + * + * @return the StringLookup + */ + public StringLookup getStringLookup() { + return this.variableResolver; + } + + // Variable Default Value Delimiter + // ----------------------------------------------------------------------- + /** + * Gets the variable default value delimiter matcher currently in use. + * <p> + * The variable default value delimiter is the character or characters that delimite the variable name and the + * variable default value. This delimiter is expressed in terms of a matcher allowing advanced variable default + * value delimiter matches. + * <p> + * If it returns null, then the variable default value resolution is disabled. + * + * @return the variable default value delimiter matcher in use, may be null + */ + public StringMatcher getValueDelimiterMatcher() { + return valueDelimiterMatcher; + } + + // Prefix + // ----------------------------------------------------------------------- + /** + * Gets the variable prefix matcher currently in use. + * <p> + * The variable prefix is the character or characters that identify the start of a variable. This prefix is + * expressed in terms of a matcher allowing advanced prefix matches. + * + * @return the prefix matcher in use + */ + public StringMatcher getVariablePrefixMatcher() { + return prefixMatcher; + } + + // Suffix + // ----------------------------------------------------------------------- + /** + * Gets the variable suffix matcher currently in use. + * <p> + * The variable suffix is the character or characters that identify the end of a variable. This suffix is expressed + * in terms of a matcher allowing advanced suffix matches. + * + * @return the suffix matcher in use + */ + public StringMatcher getVariableSuffixMatcher() { + return suffixMatcher; + } + + /** + * Returns a flag whether substitution is disabled in variable values.If set to <b>true</b>, the values of variables + * can contain other variables will not be processed and substituted original variable is evaluated, e.g. + * + * <pre> + * Map valuesMap = HashMap(); + * valuesMap.put("name", "Douglas ${surname}"); + * valuesMap.put("surname", "Crockford"); + * String templateString = "Hi ${name}"; + * StrSubstitutor sub = new StrSubstitutor(valuesMap); + * String resolvedString = sub.replace(templateString); + * </pre> + * + * yielding: + * + * <pre> + * Hi Douglas ${surname} + * </pre> + * + * @return the substitution in variable values flag + */ + public boolean isDisableSubstitutionInValues() { + return disableSubstitutionInValues; + } + + // Substitution support in variable names + // ----------------------------------------------------------------------- + /** + * Returns a flag whether substitution is done in variable names. + * + * @return the substitution in variable names flag + */ + public boolean isEnableSubstitutionInVariables() { + return enableSubstitutionInVariables; + } + + /** + * Returns the flag controlling whether escapes are preserved during substitution. + * + * @return the preserve escape flag + */ + public boolean isPreserveEscapes() { + return preserveEscapes; + } + + // ----------------------------------------------------------------------- + /** + * Replaces all the occurrences of variables with their matching values from the resolver using the given source + * array as a template. The array is not altered by this method. + * + * @param source + * the character array to replace in, not altered, null returns null + * @return the result of the replace operation + */ + public String replace(final char[] source) { + if (source == null) { + return null; + } + final StrBuilder buf = new StrBuilder(source.length).append(source); + substitute(buf, 0, source.length); + return buf.toString(); + } + + /** + * Replaces all the occurrences of variables with their matching values from the resolver using the given source + * array as a template. The array is not altered by this method. + * <p> + * Only the specified portion of the array will be processed. The rest of the array is not processed, and is not + * returned. + * + * @param source + * the character array to replace in, not altered, null returns null + * @param offset + * the start offset within the array, must be valid + * @param length + * the length within the array to be processed, must be valid + * @return the result of the replace operation + */ + public String replace(final char[] source, final int offset, final int length) { + if (source == null) { + return null; + } + final StrBuilder buf = new StrBuilder(length).append(source, offset, length); + substitute(buf, 0, length); + return buf.toString(); + } + + /** + * Replaces all the occurrences of variables with their matching values from the resolver using the given source as + * a template. The source is not altered by this method. + * + * @param source + * the buffer to use as a template, not changed, null returns null + * @return the result of the replace operation + */ + public String replace(final CharSequence source) { + if (source == null) { + return null; + } + return replace(source, 0, source.length()); + } + + /** + * Replaces all the occurrences of variables with their matching values from the resolver using the given source as + * a template. The source is not altered by this method. + * <p> + * Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, and is not + * returned. + * + * @param source + * the buffer to use as a template, not changed, null returns null + * @param offset + * the start offset within the array, must be valid + * @param length + * the length within the array to be processed, must be valid + * @return the result of the replace operation + */ + public String replace(final CharSequence source, final int offset, final int length) { + if (source == null) { + return null; + } + final StrBuilder buf = new StrBuilder(length).append(source, offset, length); + substitute(buf, 0, length); + return buf.toString(); + } + + // ----------------------------------------------------------------------- + /** + * Replaces all the occurrences of variables in the given source object with their matching values from the + * resolver. The input source object is converted to a string using <code>toString</code> and is not altered. + * + * @param source + * the source to replace in, null returns null + * @return the result of the replace operation + */ + public String replace(final Object source) { + if (source == null) { + return null; + } + final StrBuilder buf = new StrBuilder().append(source); + substitute(buf, 0, buf.length()); + return buf.toString(); + } + + // ----------------------------------------------------------------------- + /** + * Replaces all the occurrences of variables with their matching values from the resolver using the given source + * builder as a template. The builder is not altered by this method. + * + * @param source + * the builder to use as a template, not changed, null returns null + * @return the result of the replace operation + */ + public String replace(final StrBuilder source) { + if (source == null) { + return null; + } + final StrBuilder buf = new StrBuilder(source.length()).append(source); + substitute(buf, 0, buf.length()); + return buf.toString(); + } + + /** + * Replaces all the occurrences of variables with their matching values from the resolver using the given source + * builder as a template. The builder is not altered by this method. + * <p> + * Only the specified portion of the builder will be processed. The rest of the builder is not processed, and is not + * returned. + * + * @param source + * the builder to use as a template, not changed, null returns null + * @param offset + * the start offset within the array, must be valid + * @param length + * the length within the array to be processed, must be valid + * @return the result of the replace operation + */ + public String replace(final StrBuilder source, final int offset, final int length) { + if (source == null) { + return null; + } + final StrBuilder buf = new StrBuilder(length).append(source, offset, length); + substitute(buf, 0, length); + return buf.toString(); + } + + // ----------------------------------------------------------------------- + /** + * Replaces all the occurrences of variables with their matching values from the resolver using the given source + * string as a template. + * + * @param source + * the string to replace in, null returns null + * @return the result of the replace operation + */ + public String replace(final String source) { + if (source == null) { + return null; + } + final StrBuilder buf = new StrBuilder(source); + if (!substitute(buf, 0, source.length())) { + return source; + } + return buf.toString(); + } + + /** + * Replaces all the occurrences of variables with their matching values from the resolver using the given source + * string as a template. + * <p> + * Only the specified portion of the string will be processed. The rest of the string is not processed, and is not + * returned. + * + * @param source + * the string to replace in, null returns null + * @param offset + * the start offset within the array, must be valid + * @param length + * the length within the array to be processed, must be valid + * @return the result of the replace operation + */ + public String replace(final String source, final int offset, final int length) { + if (source == null) { + return null; + } + final StrBuilder buf = new StrBuilder(length).append(source, offset, length); + if (!substitute(buf, 0, length)) { + return source.substring(offset, offset + length); + } + return buf.toString(); + } + + // ----------------------------------------------------------------------- + /** + * Replaces all the occurrences of variables with their matching values from the resolver using the given source + * buffer as a template. The buffer is not altered by this method. + * + * @param source + * the buffer to use as a template, not changed, null returns null + * @return the result of the replace operation + */ + public String replace(final StringBuffer source) { + if (source == null) { + return null; + } + final StrBuilder buf = new StrBuilder(source.length()).append(source); + substitute(buf, 0, buf.length()); + return buf.toString(); + } + + /** + * Replaces all the occurrences of variables with their matching values from the resolver using the given source + * buffer as a template. The buffer is not altered by this method. + * <p> + * Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, and is not + * returned. + * + * @param source + * the buffer to use as a template, not changed, null returns null + * @param offset + * the start offset within the array, must be valid + * @param length + * the length within the array to be processed, must be valid + * @return the result of the replace operation + */ + public String replace(final StringBuffer source, final int offset, final int length) { + if (source == null) { + return null; + } + final StrBuilder buf = new StrBuilder(length).append(source, offset, length); + substitute(buf, 0, length); + return buf.toString(); + } + + // ----------------------------------------------------------------------- + /** + * Replaces all the occurrences of variables within the given source builder with their matching values from the + * resolver. + * + * @param source + * the builder to replace in, updated, null returns zero + * @return true if altered + */ + public boolean replaceIn(final StrBuilder source) { + if (source == null) { + return false; + } + return substitute(source, 0, source.length()); + } + + /** + * Replaces all the occurrences of variables within the given source builder with their matching values from the + * resolver. + * <p> + * Only the specified portion of the builder will be processed. The rest of the builder is not processed, but it is + * not deleted. + * + * @param source + * the builder to replace in, null returns zero + * @param offset + * the start offset within the array, must be valid + * @param length + * the length within the builder to be processed, must be valid + * @return true if altered + */ + public boolean replaceIn(final StrBuilder source, final int offset, final int length) { + if (source == null) { + return false; + } + return substitute(source, offset, length); + } + + // ----------------------------------------------------------------------- + /** + * Replaces all the occurrences of variables within the given source buffer with their matching values from the + * resolver. The buffer is updated with the result. + * + * @param source + * the buffer to replace in, updated, null returns zero + * @return true if altered + */ + public boolean replaceIn(final StringBuffer source) { + if (source == null) { + return false; + } + return replaceIn(source, 0, source.length()); + } + + /** + * Replaces all the occurrences of variables within the given source buffer with their matching values from the + * resolver. The buffer is updated with the result. + * <p> + * Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, but it is + * not deleted. + * + * @param source + * the buffer to replace in, updated, null returns zero + * @param offset + * the start offset within the array, must be valid + * @param length + * the length within the buffer to be processed, must be valid + * @return true if altered + */ + public boolean replaceIn(final StringBuffer source, final int offset, final int length) { + if (source == null) { + return false; + } + final StrBuilder buf = new StrBuilder(length).append(source, offset, length); + if (!substitute(buf, 0, length)) { + return false; + } + source.replace(offset, offset + length, buf.toString()); + return true; + } + + // ----------------------------------------------------------------------- + /** + * Replaces all the occurrences of variables within the given source buffer with their matching values from the + * resolver. The buffer is updated with the result. + * + * @param source + * the buffer to replace in, updated, null returns zero + * @return true if altered + */ + public boolean replaceIn(final StringBuilder source) { + if (source == null) { + return false; + } + return replaceIn(source, 0, source.length()); + } + + /** + * Replaces all the occurrences of variables within the given source builder with their matching values from the + * resolver. The builder is updated with the result. + * <p> + * Only the specified portion of the buffer will be processed. The rest of the buffer is not processed, but it is + * not deleted. + * + * @param source + * the buffer to replace in, updated, null returns zero + * @param offset + * the start offset within the array, must be valid + * @param length + * the length within the buffer to be processed, must be valid + * @return true if altered + */ + public boolean replaceIn(final StringBuilder source, final int offset, final int length) { + if (source == null) { + return false; + } + final StrBuilder buf = new StrBuilder(length).append(source, offset, length); + if (!substitute(buf, 0, length)) { + return false; + } + source.replace(offset, offset + length, buf.toString()); + return true; + } + + /** + * Internal method that resolves the value of a variable. + * <p> + * Most users of this class do not need to call this method. This method is called automatically by the substitution + * process. + * <p> + * Writers of subclasses can override this method if they need to alter how each substitution occurs. The method is + * passed the variable's name and must return the corresponding value. This implementation uses the + * {@link #getStringLookup()} with the variable's name as the key. + * + * @param variableName + * the name of the variable, not null + * @param buf + * the buffer where the substitution is occurring, not null + * @param startPos + * the start position of the variable including the prefix, valid + * @param endPos + * the end position of the variable including the suffix, valid + * @return the variable's value or <b>null</b> if the variable is unknown + */ + protected String resolveVariable(final String variableName, final StrBuilder buf, final int startPos, + final int endPos) { + final StringLookup resolver = getStringLookup(); + if (resolver == null) { + return null; + } + return resolver.lookup(variableName); + } + + /** + * Sets a flag whether substitution is done in variable values (recursive). + * + * @param disableSubstitutionInValues + * true if substitution in variable value are disabled + * @return this, to enable chaining + */ + public StringSubstitutor setDisableSubstitutionInValues(final boolean disableSubstitutionInValues) { + this.disableSubstitutionInValues = disableSubstitutionInValues; + return this; + } + + /** + * Sets a flag whether substitution is done in variable names. If set to <b>true</b>, the names of variables can + * contain other variables which are processed first before the original variable is evaluated, e.g. + * <code>${jre-${java.version}}</code>. The default value is <b>false</b>. + * + * @param enableSubstitutionInVariables + * the new value of the flag + * @return this, to enable chaining + */ + public StringSubstitutor setEnableSubstitutionInVariables(final boolean enableSubstitutionInVariables) { + this.enableSubstitutionInVariables = enableSubstitutionInVariables; + return this; + } + + /** + * Sets the escape character. If this character is placed before a variable reference in the source text, this + * variable will be ignored. + * + * @param escapeCharacter + * the escape character (0 for disabling escaping) + * @return this, to enable chaining + */ + public StringSubstitutor setEscapeChar(final char escapeCharacter) { + this.escapeChar = escapeCharacter; + return this; + } + + /** + * Sets a flag controlling whether escapes are preserved during substitution. If set to <b>true</b>, the escape + * character is retained during substitution (e.g. <code>$${this-is-escaped}</code> remains + * <code>$${this-is-escaped}</code>). If set to <b>false</b>, the escape character is removed during substitution + * (e.g. <code>$${this-is-escaped}</code> becomes <code>${this-is-escaped}</code>). The default value is + * <b>false</b> + * + * @param preserveEscapes + * true if escapes are to be preserved + * @return this, to enable chaining + */ + public StringSubstitutor setPreserveEscapes(final boolean preserveEscapes) { + this.preserveEscapes = preserveEscapes; + return this; + } + + /** + * Sets the variable default value delimiter to use. + * <p> + * The variable default value delimiter is the character or characters that delimite the variable name and the + * variable default value. This method allows a single character variable default value delimiter to be easily set. + * + * @param valueDelimiter + * the variable default value delimiter character to use + * @return this, to enable chaining + */ + public StringSubstitutor setValueDelimiter(final char valueDelimiter) { + return setValueDelimiterMatcher(StringMatcherFactory.INSTANCE.charMatcher(valueDelimiter)); + } + + /** + * Sets the variable default value delimiter to use. + * <p> + * The variable default value delimiter is the character or characters that delimite the variable name and the + * variable default value. This method allows a string variable default value delimiter to be easily set. + * <p> + * If the <code>valueDelimiter</code> is null or empty string, then the variable default value resolution becomes + * disabled. + * + * @param valueDelimiter + * the variable default value delimiter string to use, may be null or empty + * @return this, to enable chaining + */ + public StringSubstitutor setValueDelimiter(final String valueDelimiter) { + if (valueDelimiter == null || valueDelimiter.length() == 0) { + setValueDelimiterMatcher(null); + return this; + } + return setValueDelimiterMatcher(StringMatcherFactory.INSTANCE.stringMatcher(valueDelimiter)); + } + + /** + * Sets the variable default value delimiter matcher to use. + * <p> + * The variable default value delimiter is the character or characters that delimite the variable name and the + * variable default value. This delimiter is expressed in terms of a matcher allowing advanced variable default + * value delimiter matches. + * <p> + * If the <code>valueDelimiterMatcher</code> is null, then the variable default value resolution becomes disabled. + * + * @param valueDelimiterMatcher + * variable default value delimiter matcher to use, may be null + * @return this, to enable chaining + */ + public StringSubstitutor setValueDelimiterMatcher(final StringMatcher valueDelimiterMatcher) { + this.valueDelimiterMatcher = valueDelimiterMatcher; + return this; + } + + /** + * Sets the variable prefix to use. + * <p> + * The variable prefix is the character or characters that identify the start of a variable. This method allows a + * single character prefix to be easily set. + * + * @param prefix + * the prefix character to use + * @return this, to enable chaining + */ + public StringSubstitutor setVariablePrefix(final char prefix) { + return setVariablePrefixMatcher(StringMatcherFactory.INSTANCE.charMatcher(prefix)); + } + + /** + * Sets the variable prefix to use. + * <p> + * The variable prefix is the character or characters that identify the start of a variable. This method allows a + * string prefix to be easily set. + * + * @param prefix + * the prefix for variables, not null + * @return this, to enable chaining + * @throws IllegalArgumentException + * if the prefix is null + */ + public StringSubstitutor setVariablePrefix(final String prefix) { + Validate.isTrue(prefix != null, "Variable prefix must not be null!"); + return setVariablePrefixMatcher(StringMatcherFactory.INSTANCE.stringMatcher(prefix)); + } + + /** + * Sets the variable prefix matcher currently in use. + * <p> + * The variable prefix is the character or characters that identify the start of a variable. This prefix is + * expressed in terms of a matcher allowing advanced prefix matches. + * + * @param prefixMatcher + * the prefix matcher to use, null ignored + * @return this, to enable chaining + * @throws IllegalArgumentException + * if the prefix matcher is null + */ + public StringSubstitutor setVariablePrefixMatcher(final StringMatcher prefixMatcher) { + Validate.isTrue(prefixMatcher != null, "Variable prefix matcher must not be null!"); + this.prefixMatcher = prefixMatcher; + return this; + } + + /** + * Sets the VariableResolver that is used to lookup variables. + * + * @param variableResolver + * the VariableResolver + * @return this, to enable chaining + */ + public StringSubstitutor setVariableResolver(final StringLookup variableResolver) { + this.variableResolver = variableResolver; + return this; + } + + /** + * Sets the variable suffix to use. + * <p> + * The variable suffix is the character or characters that identify the end of a variable. This method allows a + * single character suffix to be easily set. + * + * @param suffix + * the suffix character to use + * @return this, to enable chaining + */ + public StringSubstitutor setVariableSuffix(final char suffix) { + return setVariableSuffixMatcher(StringMatcherFactory.INSTANCE.charMatcher(suffix)); + } + + /** + * Sets the variable suffix to use. + * <p> + * The variable suffix is the character or characters that identify the end of a variable. This method allows a + * string suffix to be easily set. + * + * @param suffix + * the suffix for variables, not null + * @return this, to enable chaining + * @throws IllegalArgumentException + * if the suffix is null + */ + public StringSubstitutor setVariableSuffix(final String suffix) { + Validate.isTrue(suffix != null, "Variable suffix must not be null!"); + return setVariableSuffixMatcher(StringMatcherFactory.INSTANCE.stringMatcher(suffix)); + } + + /** + * Sets the variable suffix matcher currently in use. + * <p> + * The variable suffix is the character or characters that identify the end of a variable. This suffix is expressed + * in terms of a matcher allowing advanced suffix matches. + * + * @param suffixMatcher + * the suffix matcher to use, null ignored + * @return this, to enable chaining + * @throws IllegalArgumentException + * if the suffix matcher is null + */ + public StringSubstitutor setVariableSuffixMatcher(final StringMatcher suffixMatcher) { + Validate.isTrue(suffixMatcher != null, "Variable suffix matcher must not be null!"); + this.suffixMatcher = suffixMatcher; + return this; + } + + // ----------------------------------------------------------------------- + /** + * Internal method that substitutes the variables. + * <p> + * Most users of this class do not need to call this method. This method will be called automatically by another + * (public) method. + * <p> + * Writers of subclasses can override this method if they need access to the substitution process at the start or + * end. + * + * @param buf + * the string builder to substitute into, not null + * @param offset + * the start offset within the builder, must be valid + * @param length + * the length within the builder to be processed, must be valid + * @return true if altered + */ + protected boolean substitute(final StrBuilder buf, final int offset, final int length) { + return substitute(buf, offset, length, null) > 0; + } + + /** + * Recursive handler for multiple levels of interpolation. This is the main interpolation method, which resolves the + * values of all variable references contained in the passed in text. + * + * @param buf + * the string builder to substitute into, not null + * @param offset + * the start offset within the builder, must be valid + * @param length + * the length within the builder to be processed, must be valid + * @param priorVariables + * the stack keeping track of the replaced variables, may be null + * @return the length change that occurs, unless priorVariables is null when the int represents a boolean flag as to + * whether any change occurred. + */ + private int substitute(final StrBuilder buf, final int offset, final int length, List<String> priorVariables) { + final StringMatcher pfxMatcher = getVariablePrefixMatcher(); + final StringMatcher suffMatcher = getVariableSuffixMatcher(); + final char escape = getEscapeChar(); + final StringMatcher valueDelimMatcher = getValueDelimiterMatcher(); + final boolean substitutionInVariablesEnabled = isEnableSubstitutionInVariables(); + final boolean substitutionInValuesDisabled = isDisableSubstitutionInValues(); + + final boolean top = priorVariables == null; + boolean altered = false; + int lengthChange = 0; + char[] chars = buf.buffer; + int bufEnd = offset + length; + int pos = offset; + while (pos < bufEnd) { + final int startMatchLen = pfxMatcher.isMatch(chars, pos, offset, bufEnd); + if (startMatchLen == 0) { + pos++; + } else { + // found variable start marker + if (pos > offset && chars[pos - 1] == escape) { + // escaped + if (preserveEscapes) { + pos++; + continue; + } + buf.deleteCharAt(pos - 1); + chars = buf.buffer; // in case buffer was altered + lengthChange--; + altered = true; + bufEnd--; + } else { + // find suffix + final int startPos = pos; + pos += startMatchLen; + int endMatchLen = 0; + int nestedVarCount = 0; + while (pos < bufEnd) { + if (substitutionInVariablesEnabled && pfxMatcher.isMatch(chars, pos, offset, bufEnd) != 0) { + // found a nested variable start + endMatchLen = pfxMatcher.isMatch(chars, pos, offset, bufEnd); + nestedVarCount++; + pos += endMatchLen; + continue; + } + + endMatchLen = suffMatcher.isMatch(chars, pos, offset, bufEnd); + if (endMatchLen == 0) { + pos++; + } else { + // found variable end marker + if (nestedVarCount == 0) { + String varNameExpr = new String(chars, startPos + startMatchLen, + pos - startPos - startMatchLen); + if (substitutionInVariablesEnabled) { + final StrBuilder bufName = new StrBuilder(varNameExpr); + substitute(bufName, 0, bufName.length()); + varNameExpr = bufName.toString(); + } + pos += endMatchLen; + final int endPos = pos; + + String varName = varNameExpr; + String varDefaultValue = null; + + if (valueDelimMatcher != null) { + final char[] varNameExprChars = varNameExpr.toCharArray(); + int valueDelimiterMatchLen = 0; + for (int i = 0; i < varNameExprChars.length; i++) { + // if there's any nested variable when nested variable substitution disabled, + // then stop resolving name and default value. + if (!substitutionInVariablesEnabled && pfxMatcher.isMatch(varNameExprChars, i, + i, varNameExprChars.length) != 0) { + break; + } + if (valueDelimMatcher.isMatch(varNameExprChars, i, 0, + varNameExprChars.length) != 0) { + valueDelimiterMatchLen = valueDelimMatcher.isMatch(varNameExprChars, i, 0, + varNameExprChars.length); + varName = varNameExpr.substring(0, i); + varDefaultValue = varNameExpr.substring(i + valueDelimiterMatchLen); + break; + } + } + } + + // on the first call initialize priorVariables + if (priorVariables == null) { + priorVariables = new ArrayList<>(); + priorVariables.add(new String(chars, offset, length)); + } + + // handle cyclic substitution + checkCyclicSubstitution(varName, priorVariables); + priorVariables.add(varName); + + // resolve the variable + String varValue = resolveVariable(varName, buf, startPos, endPos); + if (varValue == null) { + varValue = varDefaultValue; + } + if (varValue != null) { + final int varLen = varValue.length(); + buf.replace(startPos, endPos, varValue); + altered = true; + int change = 0; + if (!substitutionInValuesDisabled) { // recursive replace + change = substitute(buf, startPos, varLen, priorVariables); + } + change = change + varLen - (endPos - startPos); + pos += change; + bufEnd += change; + lengthChange += change; + chars = buf.buffer; // in case buffer was + // altered + } + + // remove variable from the cyclic stack + priorVariables.remove(priorVariables.size() - 1); + break; + } + nestedVarCount--; + pos += endMatchLen; + } + } + } + } + } + if (top) { + return altered ? 1 : 0; + } + return lengthChange; + } +}
http://git-wip-us.apache.org/repos/asf/commons-text/blob/4b67dd51/src/main/java/org/apache/commons/text/lookup/AbstractStringLookup.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/text/lookup/AbstractStringLookup.java b/src/main/java/org/apache/commons/text/lookup/AbstractStringLookup.java index bb43e96..3cbbaa3 100644 --- a/src/main/java/org/apache/commons/text/lookup/AbstractStringLookup.java +++ b/src/main/java/org/apache/commons/text/lookup/AbstractStringLookup.java @@ -19,10 +19,6 @@ package org.apache.commons.text.lookup; /** * A default lookup for others to extend in this package. - * <p> - * Unfortunately, the type {@link org.apache.commons.text.StrLookup} was defined as class and not an interface, which is - * why this package introduces the interface {@link StringLookup}. - * </p> * * @since 1.3 */ http://git-wip-us.apache.org/repos/asf/commons-text/blob/4b67dd51/src/main/java/org/apache/commons/text/lookup/StringLookup.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/text/lookup/StringLookup.java b/src/main/java/org/apache/commons/text/lookup/StringLookup.java index 4ced2c4..f3098e7 100644 --- a/src/main/java/org/apache/commons/text/lookup/StringLookup.java +++ b/src/main/java/org/apache/commons/text/lookup/StringLookup.java @@ -27,10 +27,6 @@ package org.apache.commons.text.lookup; * For example, it would be possible to implement a lookup that used the key as a primary key, and looked up the value * on demand from the database * </p> - * <p> - * Unfortunately, the type {@link org.apache.commons.text.StrLookup} was defined as class and not an interface, which is - * why this package introduces the interface {@link StringLookup}. - * </p> * * @since 1.3 */ http://git-wip-us.apache.org/repos/asf/commons-text/blob/4b67dd51/src/main/java/org/apache/commons/text/lookup/package-info.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/text/lookup/package-info.java b/src/main/java/org/apache/commons/text/lookup/package-info.java index b53399a..528211b 100644 --- a/src/main/java/org/apache/commons/text/lookup/package-info.java +++ b/src/main/java/org/apache/commons/text/lookup/package-info.java @@ -16,7 +16,7 @@ */ /** * <p> - * Provides algorithms for looking up strings for use with a {@link org.apache.commons.text.StrSubstitutor}. The main + * Provides algorithms for looking up strings for use with a {@link org.apache.commons.text.StringSubstitutor}. The main * class here is {@link org.apache.commons.text.lookup.StringLookupFactory} * </p> * http://git-wip-us.apache.org/repos/asf/commons-text/blob/4b67dd51/src/main/java/org/apache/commons/text/matcher/AbstractStringMatcher.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/text/matcher/AbstractStringMatcher.java b/src/main/java/org/apache/commons/text/matcher/AbstractStringMatcher.java new file mode 100644 index 0000000..34f9771 --- /dev/null +++ b/src/main/java/org/apache/commons/text/matcher/AbstractStringMatcher.java @@ -0,0 +1,256 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.commons.text.matcher; + +import java.util.Arrays; + +/** + * A matcher class that can be queried to determine if a character array portion matches. + * <p> + * This class comes complete with various factory methods. If these do not suffice, you can subclass and implement your + * own matcher. + * + * @since 1.3 + */ +abstract class AbstractStringMatcher implements StringMatcher { + + /** + * Class used to define a character for matching purposes. + */ + static final class CharMatcher extends AbstractStringMatcher { + /** The character to match. */ + private final char ch; + + /** + * Constructor that creates a matcher that matches a single character. + * + * @param ch + * the character to match + */ + CharMatcher(final char ch) { + super(); + this.ch = ch; + } + + /** + * Returns whether or not the given character matches. + * + * @param buffer + * the text content to match against, do not change + * @param pos + * the starting position for the match, valid for buffer + * @param bufferStart + * the first active index in the buffer, valid for buffer + * @param bufferEnd + * the end index of the active buffer, valid for buffer + * @return the number of matching characters, zero for no match + */ + @Override + public int isMatch(final char[] buffer, final int pos, final int bufferStart, final int bufferEnd) { + return ch == buffer[pos] ? 1 : 0; + } + } + + /** + * Class used to define a set of characters for matching purposes. + */ + static final class CharSetMatcher extends AbstractStringMatcher { + /** The set of characters to match. */ + private final char[] chars; + + /** + * Constructor that creates a matcher from a character array. + * + * @param chars + * the characters to match, must not be null + */ + CharSetMatcher(final char[] chars) { + super(); + this.chars = chars.clone(); + Arrays.sort(this.chars); + } + + /** + * Returns whether or not the given character matches. + * + * @param buffer + * the text content to match against, do not change + * @param pos + * the starting position for the match, valid for buffer + * @param bufferStart + * the first active index in the buffer, valid for buffer + * @param bufferEnd + * the end index of the active buffer, valid for buffer + * @return the number of matching characters, zero for no match + */ + @Override + public int isMatch(final char[] buffer, final int pos, final int bufferStart, final int bufferEnd) { + return Arrays.binarySearch(chars, buffer[pos]) >= 0 ? 1 : 0; + } + } + + /** + * Class used to match no characters. + */ + static final class NoMatcher extends AbstractStringMatcher { + + /** + * Constructs a new instance of <code>NoMatcher</code>. + */ + NoMatcher() { + super(); + } + + /** + * Always returns <code>false</code>. + * + * @param buffer + * the text content to match against, do not change + * @param pos + * the starting position for the match, valid for buffer + * @param bufferStart + * the first active index in the buffer, valid for buffer + * @param bufferEnd + * the end index of the active buffer, valid for buffer + * @return the number of matching characters, zero for no match + */ + @Override + public int isMatch(final char[] buffer, final int pos, final int bufferStart, final int bufferEnd) { + return 0; + } + } + + /** + * Class used to define a set of characters for matching purposes. + */ + static final class StringMatcher extends AbstractStringMatcher { + /** The string to match, as a character array. */ + private final char[] chars; + + /** + * Constructor that creates a matcher from a String. + * + * @param str + * the string to match, must not be null + */ + StringMatcher(final String str) { + super(); + chars = str.toCharArray(); + } + + /** + * Returns whether or not the given text matches the stored string. + * + * @param buffer + * the text content to match against, do not change + * @param pos + * the starting position for the match, valid for buffer + * @param bufferStart + * the first active index in the buffer, valid for buffer + * @param bufferEnd + * the end index of the active buffer, valid for buffer + * @return the number of matching characters, zero for no match + */ + @Override + public int isMatch(final char[] buffer, int pos, final int bufferStart, final int bufferEnd) { + final int len = chars.length; + if (pos + len > bufferEnd) { + return 0; + } + for (int i = 0; i < chars.length; i++, pos++) { + if (chars[i] != buffer[pos]) { + return 0; + } + } + return len; + } + + @Override + public String toString() { + return super.toString() + ' ' + Arrays.toString(chars); + } + + } + + /** + * Class used to match whitespace as per trim(). + */ + static final class TrimMatcher extends AbstractStringMatcher { + + /** + * The space character. + */ + private static final int SPACE_INT = 32; + + /** + * Constructs a new instance of <code>TrimMatcher</code>. + */ + TrimMatcher() { + super(); + } + + /** + * Returns whether or not the given character matches. + * + * @param buffer + * the text content to match against, do not change + * @param pos + * the starting position for the match, valid for buffer + * @param bufferStart + * the first active index in the buffer, valid for buffer + * @param bufferEnd + * the end index of the active buffer, valid for buffer + * @return the number of matching characters, zero for no match + */ + @Override + public int isMatch(final char[] buffer, final int pos, final int bufferStart, final int bufferEnd) { + return buffer[pos] <= SPACE_INT ? 1 : 0; + } + } + + /** + * Constructor. + */ + protected AbstractStringMatcher() { + super(); + } + + /** + * Returns the number of matching characters, zero for no match. + * <p> + * This method is called to check for a match. The parameter <code>pos</code> represents the current position to be + * checked in the string <code>buffer</code> (a character array which must not be changed). The API guarantees that + * <code>pos</code> is a valid index for <code>buffer</code>. + * <p> + * The matching code may check one character or many. It may check characters preceding <code>pos</code> as well as + * those after. + * <p> + * It must return zero for no match, or a positive number if a match was found. The number indicates the number of + * characters that matched. + * + * @param buffer + * the text content to match against, do not change + * @param pos + * the starting position for the match, valid for buffer + * @return the number of matching characters, zero for no match + */ + public int isMatch(final char[] buffer, final int pos) { + return isMatch(buffer, pos, 0, buffer.length); + } + +} http://git-wip-us.apache.org/repos/asf/commons-text/blob/4b67dd51/src/main/java/org/apache/commons/text/matcher/StringMatcher.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/text/matcher/StringMatcher.java b/src/main/java/org/apache/commons/text/matcher/StringMatcher.java new file mode 100644 index 0000000..4133955 --- /dev/null +++ b/src/main/java/org/apache/commons/text/matcher/StringMatcher.java @@ -0,0 +1,55 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.commons.text.matcher; + +/** + * Determines if a character array portion matches. + * + * @since 1.3 + */ +public interface StringMatcher { + + /** + * Returns the number of matching characters, zero for no match. + * <p> + * This method is called to check for a match. The parameter <code>pos</code> represents the current position to be + * checked in the string <code>buffer</code> (a character array which must not be changed). The API guarantees that + * <code>pos</code> is a valid index for <code>buffer</code>. + * <p> + * The character array may be larger than the active area to be matched. Only values in the buffer between the + * specified indices may be accessed. + * <p> + * The matching code may check one character or many. It may check characters preceding <code>pos</code> as well as + * those after, so long as no checks exceed the bounds specified. + * <p> + * It must return zero for no match, or a positive number if a match was found. The number indicates the number of + * characters that matched. + * + * @param buffer + * the text content to match against, do not change + * @param pos + * the starting position for the match, valid for buffer + * @param bufferStart + * the first active index in the buffer, valid for buffer + * @param bufferEnd + * the end index (exclusive) of the active buffer, valid for buffer + * @return the number of matching characters, or zero if there is no match + */ + int isMatch(char[] buffer, int pos, int bufferStart, int bufferEnd); + +} http://git-wip-us.apache.org/repos/asf/commons-text/blob/4b67dd51/src/main/java/org/apache/commons/text/matcher/StringMatcherFactory.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/text/matcher/StringMatcherFactory.java b/src/main/java/org/apache/commons/text/matcher/StringMatcherFactory.java new file mode 100644 index 0000000..988d150 --- /dev/null +++ b/src/main/java/org/apache/commons/text/matcher/StringMatcherFactory.java @@ -0,0 +1,228 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.commons.text.matcher; + +/** + * Provides access to matchers defined in this package. + * + * @since 1.3 + */ +public final class StringMatcherFactory { + + /** + * Defines the singleton for this class. + */ + public static final StringMatcherFactory INSTANCE = new StringMatcherFactory(); + + /** + * Matches the same characters as StringTokenizer, namely space, tab, newline, form feed. + */ + private static final AbstractStringMatcher.CharSetMatcher SPLIT_MATCHER = new AbstractStringMatcher.CharSetMatcher( + " \t\n\r\f".toCharArray()); + + /** + * Matches the comma character. + */ + private static final AbstractStringMatcher.CharMatcher COMMA_MATCHER = new AbstractStringMatcher.CharMatcher(','); + + /** + * Matches the tab character. + */ + private static final AbstractStringMatcher.CharMatcher TAB_MATCHER = new AbstractStringMatcher.CharMatcher('\t'); + + /** + * Matches the space character. + */ + private static final AbstractStringMatcher.CharMatcher SPACE_MATCHER = new AbstractStringMatcher.CharMatcher(' '); + + /** + * Matches the String trim() whitespace characters. + */ + private static final AbstractStringMatcher.TrimMatcher TRIM_MATCHER = new AbstractStringMatcher.TrimMatcher(); + + /** + * Matches the double quote character. + */ + private static final AbstractStringMatcher.CharMatcher SINGLE_QUOTE_MATCHER = new AbstractStringMatcher.CharMatcher( + '\''); + + /** + * Matches the double quote character. + */ + private static final AbstractStringMatcher.CharMatcher DOUBLE_QUOTE_MATCHER = new AbstractStringMatcher.CharMatcher( + '"'); + + /** + * Matches the single or double quote character. + */ + private static final AbstractStringMatcher.CharSetMatcher QUOTE_MATCHER = new AbstractStringMatcher.CharSetMatcher( + "'\"".toCharArray()); + + /** + * Matches no characters. + */ + private static final AbstractStringMatcher.NoMatcher NONE_MATCHER = new AbstractStringMatcher.NoMatcher(); + + /** + * No need to build instances for now. + */ + private StringMatcherFactory() { + // empty + } + + /** + * Constructor that creates a matcher from a character. + * + * @param ch + * the character to match, must not be null + * @return a new Matcher for the given char + */ + public StringMatcher charMatcher(final char ch) { + return new AbstractStringMatcher.CharMatcher(ch); + } + + /** + * Constructor that creates a matcher from a set of characters. + * + * @param chars + * the characters to match, null or empty matches nothing + * @return a new matcher for the given char[] + */ + public StringMatcher charSetMatcher(final char... chars) { + if (chars == null || chars.length == 0) { + return NONE_MATCHER; + } + if (chars.length == 1) { + return new AbstractStringMatcher.CharMatcher(chars[0]); + } + return new AbstractStringMatcher.CharSetMatcher(chars); + } + + /** + * Creates a matcher from a string representing a set of characters. + * + * @param chars + * the characters to match, null or empty matches nothing + * @return a new Matcher for the given characters + */ + public StringMatcher charSetMatcher(final String chars) { + if (chars == null || chars.length() == 0) { + return NONE_MATCHER; + } + if (chars.length() == 1) { + return new AbstractStringMatcher.CharMatcher(chars.charAt(0)); + } + return new AbstractStringMatcher.CharSetMatcher(chars.toCharArray()); + } + + /** + * Returns a matcher which matches the comma character. + * + * @return a matcher for a comma + */ + public StringMatcher commaMatcher() { + return COMMA_MATCHER; + } + + /** + * Returns a matcher which matches the double quote character. + * + * @return a matcher for a double quote + */ + public StringMatcher doubleQuoteMatcher() { + return DOUBLE_QUOTE_MATCHER; + } + + /** + * Matches no characters. + * + * @return a matcher that matches nothing + */ + public StringMatcher noneMatcher() { + return NONE_MATCHER; + } + + /** + * Returns a matcher which matches the single or double quote character. + * + * @return a matcher for a single or double quote + */ + public StringMatcher quoteMatcher() { + return QUOTE_MATCHER; + } + + /** + * Returns a matcher which matches the single quote character. + * + * @return a matcher for a single quote + */ + public StringMatcher singleQuoteMatcher() { + return SINGLE_QUOTE_MATCHER; + } + + /** + * Returns a matcher which matches the space character. + * + * @return a matcher for a space + */ + public StringMatcher spaceMatcher() { + return SPACE_MATCHER; + } + + /** + * Matches the same characters as StringTokenizer, namely space, tab, newline and form feed. + * + * @return the split matcher + */ + public StringMatcher splitMatcher() { + return SPLIT_MATCHER; + } + + /** + * Creates a matcher from a string. + * + * @param str + * the string to match, null or empty matches nothing + * @return a new Matcher for the given String + */ + public StringMatcher stringMatcher(final String str) { + if (str == null || str.length() == 0) { + return NONE_MATCHER; + } + return new AbstractStringMatcher.StringMatcher(str); + } + + /** + * Returns a matcher which matches the tab character. + * + * @return a matcher for a tab + */ + public StringMatcher tabMatcher() { + return TAB_MATCHER; + } + + /** + * Matches the String trim() whitespace characters. + * + * @return the trim matcher + */ + public StringMatcher trimMatcher() { + return TRIM_MATCHER; + } + +} http://git-wip-us.apache.org/repos/asf/commons-text/blob/4b67dd51/src/main/java/org/apache/commons/text/matcher/package-info.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/text/matcher/package-info.java b/src/main/java/org/apache/commons/text/matcher/package-info.java new file mode 100644 index 0000000..a7a3aae --- /dev/null +++ b/src/main/java/org/apache/commons/text/matcher/package-info.java @@ -0,0 +1,25 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +/** + * <p> + * Provides algorithms for matching up strings for use with a {@link org.apache.commons.text.StringSubstitutor}. The + * main class here is {@link org.apache.commons.text.matcher.StringMatcherFactory} + * </p> + * + * @since 1.3 + */ +package org.apache.commons.text.matcher;
