Add validate methods for all elements same type

bug 25683, from Norm Deane


git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@137788 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/lang/Validate.java

@@ -71,8 +71,9 @@
  * @author <a href="mailto:ola.berg@arkitema.se">Ola Berg</a>
  * @author Stephen Colebourne
  * @author Gary Gregory
+ * @author Norm Deane
  * @since 2.0
- * @version $Id: Validate.java,v 1.8 2004/02/11 23:33:23 ggregory Exp $
+ * @version $Id: Validate.java,v 1.9 2004/02/14 00:48:19 scolebourne Exp $
  */
 public class Validate {
     
@@ -528,5 +529,54 @@ public static void noNullElements(Collection collection) {
             }
         }
     }
+    
+    /**
+     * <p>Validate an argument, throwing <code>IllegalArgumentException</code>
+     * if the argument collection  is <code>null</code> or has elements that
+     * are not of type <code>clazz</code>.</p>
+     *
+     * <pre>
+     * Validate.allElementsOfClass(collection, String.class, "Collection has invalid elements");
+     * </pre>
+     *
+     * @param collection  the collection to check
+     * @param clazz  the <code>Class</code> which the collection's elements are expected to be
+     * @param message  the exception message if the <code>Collection</code> has elements not of type <code>clazz</code>
+     * @since 2.1
+     */
+    public static void allElementsOfClass(Collection collection, Class clazz, String message) {
+    	Validate.notNull(collection);
+    	for (Iterator it = collection.iterator(); it.hasNext(); ) {
+    		if ((it.next().getClass().equals(clazz)) == false) {
+    			throw new IllegalArgumentException(message);
+    		}
+    	}
+    }   
+    
+    /**
+     * <p>Validate an argument, throwing <code>IllegalArgumentException</code>
+     * if the argument collection  is <code>null</code> or has elements that are not of 
+     * type <code>clazz</code>.</p>
+     *
+     * <pre>
+     * Validate.allElementsOfClass(collection, String.class);
+     * </pre>
+     *
+     * <p>The message in the exception is 'The validated collection contains an element not of type clazz at index: '.</p>
+     * 
+     * @param collection  the collection to check
+     * @param clazz the <code>Class</code> which the collection's elements are expected to be
+     * @since 2.1
+     */
+    public static void allElementsOfClass(Collection collection, Class clazz) {
+    	Validate.notNull(collection);
+    	int i = 0;
+    	for (Iterator it = collection.iterator(); it.hasNext(); i++) {
+    		if ((it.next().getClass().equals(clazz)) == false) {
+    			throw new IllegalArgumentException("The validated collection contains an element not of type "
+                    + (clazz == null ? "null" : clazz.getName()) + " at index: " + i);
+    		}
+    	}
+    }
 
 }

src/test/org/apache/commons/lang/ValidateTest.java

@@ -67,7 +67,8 @@
  * Unit tests {@link org.apache.commons.lang.util.Validate}.
  *
  * @author Stephen Colebourne
- * @version $Id: ValidateTest.java,v 1.3 2003/08/19 02:32:16 bayard Exp $
+ * @author Norm Deane
+ * @version $Id: ValidateTest.java,v 1.4 2004/02/14 00:48:20 scolebourne Exp $
  */
 public class ValidateTest extends TestCase {
 
@@ -395,4 +396,23 @@ public void testNoNullElementsCollection2() {
     }
 
     //-----------------------------------------------------------------------
+    public void testAllElementsOfClass() {
+    	List coll = new ArrayList();
+    	coll.add("a");
+    	coll.add("b");
+    	Validate.allElementsOfClass(coll, String.class, "MSG");
+    	try {
+    		Validate.allElementsOfClass(coll, Integer.class, "MSG");
+    		fail("Expecting IllegalArgumentException");
+    	} catch (IllegalArgumentException ex) {
+    		assertEquals("MSG", ex.getMessage());
+    	}
+    	coll.set(1, Boolean.FALSE);
+    	try {
+    		Validate.allElementsOfClass(coll, String.class);
+    		fail("Expecting IllegalArgumentException");
+    	} catch (IllegalArgumentException ex) {
+    		assertEquals("The validated collection contains an element not of type java.lang.String at index: 1", ex.getMessage());
+    	}
+    }
 }