Author: julien(a)jboss.com Date: 2008-03-20 10:20:47 -0400 (Thu, 20 Mar 2008) New Revision: 10349 Modified: modules/common/trunk/common/src/main/java/org/jboss/portal/common/reflect/Reflection.java modules/common/trunk/common/src/test/java/org/jboss/portal/test/common/reflect/ReflectionTestCase.java Log: added a safe cast util method Modified: modules/common/trunk/common/src/main/java/org/jboss/portal/common/reflect/Reflection.java =================================================================== --- modules/common/trunk/common/src/main/java/org/jboss/portal/common/reflect/Reflection.java 2008-03-20 03:52:18 UTC (rev 10348) +++ modules/common/trunk/common/src/main/java/org/jboss/portal/common/reflect/Reflection.java 2008-03-20 14:20:47 UTC (rev 10349) @@ -139,4 +139,30 @@ return null; } + /** + * Attempt to cast the value argument to the provided type argument. If the value argument type is assignable + * to the provided type, the value is returned, otherwise if it is not or the value is null, null is returned. + * + * @param value the value to cast + * @param type the type to downcast + * @return the casted value or null + */ + public static <T> T safeCast(Object value, Class<T> type) + { + if (value == null) + { + return null; + } + else + { + if (type.isAssignableFrom(value.getClass())) + { + return type.cast(value); + } + else + { + return null; + } + } + } } Modified: modules/common/trunk/common/src/test/java/org/jboss/portal/test/common/reflect/ReflectionTestCase.java =================================================================== --- modules/common/trunk/common/src/test/java/org/jboss/portal/test/common/reflect/ReflectionTestCase.java 2008-03-20 03:52:18 UTC (rev 10348) +++ modules/common/trunk/common/src/test/java/org/jboss/portal/test/common/reflect/ReflectionTestCase.java 2008-03-20 14:20:47 UTC (rev 10349) @@ -26,6 +26,9 @@ import java.lang.reflect.Method; import java.lang.reflect.Modifier; +import java.util.ArrayList; +import java.util.List; +import java.util.AbstractList; import org.jboss.portal.common.reflect.Reflection; @@ -87,4 +90,18 @@ assertEquals(methodName, effectiveMethod.getName()); } + public void testSafeCast() + { + Integer i = 3; + assertSame(i, Reflection.safeCast(i, Integer.class)); + + // + assertNull(Reflection.safeCast(3L, Integer.class)); + + // + ArrayList list = new ArrayList(); + assertSame(list, Reflection.safeCast(list, List.class)); + assertSame(list, Reflection.safeCast(list, AbstractList.class)); + } + }