cvs commit: jakarta-commons/collections/src/test/org/apache/commons/collections TestTransformerUtils.java

[sc...@apache.org]

scolebourne    2003/09/17 13:28:30

  Modified:    collections/src/java/org/apache/commons/collections
                        TransformerUtils.java
               collections/src/test/org/apache/commons/collections
                        TestTransformerUtils.java
  Log:
  Add StringValue transformer
  from  James Carman
  
  Revision  Changes    Path
  1.4       +40 -3     jakarta-commons/collections/src/java/org/apache/commons/collections/TransformerUtils.java
  
  Index: TransformerUtils.java
  ===================================================================
  RCS file: /home/cvs/jakarta-commons/collections/src/java/org/apache/commons/collections/TransformerUtils.java,v
  retrieving revision 1.3
  retrieving revision 1.4
  diff -u -r1.3 -r1.4
  --- TransformerUtils.java	31 Aug 2003 17:26:44 -0000	1.3
  +++ TransformerUtils.java	17 Sep 2003 20:28:30 -0000	1.4
  @@ -82,6 +82,7 @@
    * <li>Null - always returns null
    * <li>NOP - returns the input object, which should be immutable
    * <li>Exception - always throws an exception
  + * <li>StringValue - returns a <code>java.lang.String</code> representation of the input object
    * </ul>
    * All the supplied transformers are Serializable.
    *
  @@ -89,6 +90,7 @@
    * @version $Revision$ $Date$
    * 
    * @author Stephen Colebourne
  + * @author James Carman
    */
   public class TransformerUtils {
   
  @@ -114,6 +116,12 @@
       private static final Transformer INSTANTIATE_TRANSFORMER = new InstantiateTransformer(null, null);
   
       /**
  +     * A transformer that returns a <code>java.lang.String</code> representation
  +     * of the input object.
  +     */
  +    private static final Transformer STRING_VALUE_TRANSFORMER = new StringValueTransformer();
  +    
  +    /**
        * This class is not normally instantiated.
        */
       public TransformerUtils() {
  @@ -491,6 +499,17 @@
       }
   
       /**
  +     * Gets a transformer that returns a <code>java.lang.String</code>
  +     * representation of the input object. This is achieved via the
  +     * <code>toString</code> method, <code>null</code> returns 'null'.
  +     * 
  +     * @return the transformer
  +     */
  +    public static Transformer stringValueTransformer() {
  +        return STRING_VALUE_TRANSFORMER;
  +    }
  +    
  +    /**
        * Copy method
        * 
        * @param predicates  the predicates to copy
  @@ -934,5 +953,23 @@
               }
           }
       }
  +    
  +    // StringValueTransformer
  +    //----------------------------------------------------------------------------------
  +
  +    /**
  +     * StringValueTransformer returns a <code>java.lang.String</code> representation
  +     * of the input object using the <code>String.valueOf()</code> method.
  +     */
  +    private static class StringValueTransformer implements Transformer, Serializable {
  +        
  +        /**
  +         * returns a <code>java.lang.String</code> representation of the input object 
  +         * using the <code>String.valueOf()</code> method.
  +         */
  +        public Object transform(Object input) {
  +            return String.valueOf(input);
  +        }
  +    }
   
  -}
  +}                                                                                                                                                                                                                                                                                                
  \ No newline at end of file
  
  
  
  1.3       +15 -2     jakarta-commons/collections/src/test/org/apache/commons/collections/TestTransformerUtils.java
  
  Index: TestTransformerUtils.java
  ===================================================================
  RCS file: /home/cvs/jakarta-commons/collections/src/test/org/apache/commons/collections/TestTransformerUtils.java,v
  retrieving revision 1.2
  retrieving revision 1.3
  diff -u -r1.2 -r1.3
  --- TestTransformerUtils.java	31 Aug 2003 17:28:43 -0000	1.2
  +++ TestTransformerUtils.java	17 Sep 2003 20:28:30 -0000	1.3
  @@ -75,6 +75,7 @@
    * @version $Revision$ $Date$
    *
    * @author Stephen Colebourne
  + * @author James Carman
    */
   public class TestTransformerUtils extends junit.framework.TestCase {
   
  @@ -533,6 +534,18 @@
               return;
           }
           fail();
  +    }
  +    
  +    // stringValueTransformer
  +    //------------------------------------------------------------------
  +    
  +    public void testStringValueTransformer() {
  +        assertNotNull( "StringValueTransformer should NEVER return a null value.",
  +           TransformerUtils.stringValueTransformer().transform(null));
  +        assertEquals( "StringValueTransformer should return \"null\" when given a null argument.", "null",
  +            TransformerUtils.stringValueTransformer().transform(null));
  +        assertEquals( "StringValueTransformer should return toString value", "6",
  +            TransformerUtils.stringValueTransformer().transform(new Integer(6)));
       }
       
   }