remkop commented on a change in pull request #284: LOG4J2-2639 - Allow logging calls to be constructed using a builder pattern URL: https://github.com/apache/logging-log4j2/pull/284#discussion_r297015735
########## File path: log4j-api/src/main/java/org/apache/logging/log4j/internal/DefaultLogBuilder.java ########## @@ -0,0 +1,179 @@ +/* + * 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.logging.log4j.internal; + +import org.apache.logging.log4j.Level; +import org.apache.logging.log4j.Logger; +import org.apache.logging.log4j.Marker; +import org.apache.logging.log4j.message.Message; +import org.apache.logging.log4j.message.SimpleMessage; +import org.apache.logging.log4j.status.StatusLogger; +import org.apache.logging.log4j.util.StackLocatorUtil; +import org.apache.logging.log4j.util.Supplier; + + +/** + * Collects data for a log event and then logs it. + */ +public class DefaultLogBuilder implements LogBuilder { + private static Message EMPTY_MESSAGE = new SimpleMessage(""); + private static final String FQCN = DefaultLogBuilder.class.getName(); + private static final Logger LOGGER = StatusLogger.getLogger(); + + private final Logger logger; + private Level level; + private Marker marker; + private Throwable throwable; + private StackTraceElement location; + private Object object; + private Message msg; + private String textMessage; + private Supplier<Message> supplier; + private Object[] parameters; + private volatile boolean inUse; + private long threadId; + + public DefaultLogBuilder(Logger logger) { + this.logger = logger; + this.inUse = false; + this.threadId = Thread.currentThread().getId(); + } + + public LogBuilder setLevel(Level level) { + this.inUse = true; + this.level = level; + this.marker = null; + this.throwable = null; + this.location = null; + this.object = null; + this.msg = null; + this.textMessage = null; + this.supplier = null; + this.parameters = null; + return this; + } + + public LogBuilder withMarker(Marker marker) { + this.marker = marker; + return this; + } + + public LogBuilder withThrowable(Throwable throwable) { + this.throwable = throwable; + return this; + } + + public LogBuilder withLocation() { + location = StackLocatorUtil.getStackTraceElement(2); + return this; + } + + public LogBuilder withLocation(StackTraceElement location) { + this.location = location; + return this; + } + + public LogBuilder withMessage(String msg) { + this.textMessage = msg; + return this; + } + + public LogBuilder withMessage(Object msg) { + this.object = msg; + return this; + } + + public LogBuilder withMessage(Message msg) { + this.msg = msg; + return this; + } + + public LogBuilder withMessage(Supplier<Message> supplier) { + this.supplier = supplier; + return this; + } + + public LogBuilder withParameters(Object... params) { + if (params != null && params.length > 0) { + if (parameters == null) { + parameters = params; + } else { + Object[] prev = parameters; + int count = parameters.length + params.length; + parameters = new Object[count]; + System.arraycopy(prev, 0, parameters, 0, prev.length); + System.arraycopy(params, 0, parameters, prev.length, params.length); + } + } + return this; + } + + @SafeVarargs + public final LogBuilder withParameters(java.util.function.Supplier<Object>... params) { + if (params != null && params.length > 0) { + if (parameters == null) { + parameters = new Object[params.length]; + for (int i = 0; i < params.length; ++i) { + parameters[i] = params[i].get(); + } + } else { + Object[] prev = parameters; + int count = parameters.length + params.length; + parameters = new Object[count]; + System.arraycopy(prev, 0, parameters, 0, prev.length); + for (int i = 0; i < params.length; ++i) { + parameters[prev.length + i] = params[i].get(); + } + } + } + return this; + } + + public boolean isInUse() { + return inUse; + } + + public void log() { + if (!inUse) { Review comment: About the logger method naming: I'm generally in favor of short names and I liked Gary's suggestion. However, looking at it some more, in this case there may be something to be said for prefixing the new "fluent" methods with `at`; * it makes the fluent methods stick out from the "normal" `info(String)`, `trace(Message)`, etc Logger methods. I think it is nice if they look different, because they are quite different. * users coding in an IDE will have the advantage of typing "at<Ctl+space>" and get completions for the fluent methods. * it is nice if the `atLevel(Level)` method is consistently named with the `atInfo`, `atDebug`, etc other fluent methods. @garydgregory (and others), what do you think? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
