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The following commit(s) were added to refs/heads/master by this push:
new c47e5f9 [LANG-1498] Add support of lambda value evaluation for
defaulting methods #416.
c47e5f9 is described below
commit c47e5f95f6853f127c291ef2293edd9a28aceec6
Author: Gary Gregory <gardgreg...@gmail.com>
AuthorDate: Thu Oct 31 21:16:17 2019 -0400
[LANG-1498] Add support of lambda value evaluation for defaulting
methods #416.
Add org.apache.commons.lang3.ObjectUtils.defaultIfNull(T, Supplier<T>).
---
src/changes/changes.xml | 1 +
.../java/org/apache/commons/lang3/ObjectUtils.java | 27 ++++++++++++++++++++--
.../org/apache/commons/lang3/ObjectUtilsTest.java | 15 +++++++++++-
3 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index 89bd6e6..c24b139 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -79,6 +79,7 @@ The <action> type attribute can be add,update,fix,remove.
<action issue="LANG-1494" type="add" dev="ggregory" due-to="Gary
Gregory">Add org.apache.commons.lang3.time.Calendars.</action>
<action issue="LANG-1495" type="add" dev="ggregory" due-to="Cheong Voon
Leong">Add EnumUtils getEnum() methods with default values #475.</action>
<action issue="LANG-1177" type="add" dev="ggregory" due-to="Liel
Fridman">Added indexesOf methods and simplified removeAllOccurences
#471.</action>
+ <action issue="LANG-1498" type="add" dev="ggregory" due-to="Lysergid, Gary
Gregory">Add support of lambda value evaluation for defaulting methods
#416.</action>
</release>
<release version="3.9" date="2019-04-09" description="New features and bug
fixes. Requires Java 8, supports Java 9, 10, 11.">
diff --git a/src/main/java/org/apache/commons/lang3/ObjectUtils.java
b/src/main/java/org/apache/commons/lang3/ObjectUtils.java
index 4a84c4f..58f0b19 100644
--- a/src/main/java/org/apache/commons/lang3/ObjectUtils.java
+++ b/src/main/java/org/apache/commons/lang3/ObjectUtils.java
@@ -27,6 +27,7 @@ import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeSet;
+import java.util.function.Supplier;
import org.apache.commons.lang3.exception.CloneFailedException;
import org.apache.commons.lang3.mutable.MutableInt;
@@ -153,8 +154,30 @@ public class ObjectUtils {
return !isEmpty(object);
}
- // Defaulting
- //-----------------------------------------------------------------------
+ /**
+ * <p>Returns the given {@code object} is it is non-null, otherwise
returns the Supplier's get value.</p>
+ *
+ * <p>The caller responsible for thread-safety and exception handling of
default value supplier.</p>
+ *
+ * <pre>
+ * ObjectUtils.getIfNull(null, () -> null) = null
+ * ObjectUtils.getIfNull(null, null) = null
+ * ObjectUtils.getIfNull(null, () -> "") = ""
+ * ObjectUtils.getIfNull(null, () -> "zz") = "zz"
+ * ObjectUtils.getIfNull("abc", *) = "abc"
+ * ObjectUtils.getIfNull(Boolean.TRUE, *) = Boolean.TRUE
+ * </pre>
+ *
+ * @param <T> the type of the object
+ * @param object the {@code Object} to test, may be {@code null}
+ * @param defaultValueSupplier the default value to return, may be {@code
null}
+ * @return {@code object} if it is not {@code null}, {@code
defaultValueSupplier.get()} otherwise
+ * @since 3.10
+ */
+ public static <T> T defaultIfNull(final T object, final Supplier<T>
defaultValueSupplier) {
+ return object != null ? object : defaultValueSupplier == null ? null :
defaultValueSupplier.get();
+ }
+
/**
* <p>Returns a default value if the object passed is {@code null}.</p>
*
diff --git a/src/test/java/org/apache/commons/lang3/ObjectUtilsTest.java
b/src/test/java/org/apache/commons/lang3/ObjectUtilsTest.java
index 45ad9b9..22f3e8e 100644
--- a/src/test/java/org/apache/commons/lang3/ObjectUtilsTest.java
+++ b/src/test/java/org/apache/commons/lang3/ObjectUtilsTest.java
@@ -40,8 +40,10 @@ import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
+import java.util.function.Supplier;
import org.apache.commons.lang3.exception.CloneFailedException;
+import org.apache.commons.lang3.mutable.MutableInt;
import org.apache.commons.lang3.mutable.MutableObject;
import org.apache.commons.lang3.text.StrBuilder;
import org.junit.jupiter.api.Test;
@@ -109,11 +111,22 @@ public class ObjectUtilsTest {
//-----------------------------------------------------------------------
@Test
- public void testIsNull() {
+ public void testDefaultIfNull() {
final Object o = FOO;
final Object dflt = BAR;
assertSame(dflt, ObjectUtils.defaultIfNull(null, dflt), "dflt was not
returned when o was null");
assertSame(o, ObjectUtils.defaultIfNull(o, dflt), "dflt was returned
when o was not null");
+ assertSame(dflt, ObjectUtils.defaultIfNull(null, () -> dflt), "dflt
was not returned when o was null");
+ assertSame(o, ObjectUtils.defaultIfNull(o, () -> dflt), "dflt was
returned when o was not null");
+ MutableInt callsCounter = new MutableInt(0);
+ Supplier<Object> countingDefaultSupplier = () -> {
+ callsCounter.increment();
+ return dflt;
+ };
+ ObjectUtils.defaultIfNull(o, countingDefaultSupplier);
+ assertEquals(0, callsCounter.getValue());
+ ObjectUtils.defaultIfNull(null, countingDefaultSupplier);
+ assertEquals(1, callsCounter.getValue());
}
@Test
