Add additional javadoc

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/collections/trunk@131665 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/collections/Closure.java

@@ -18,18 +18,21 @@ package org.apache.commons.collections;
 /**
  * Defines a functor interface implemented by classes that do something.
  * <p>
- * A Closure represents a block of code which is executed from inside some
- * block, function or iteration. It operates an input object.
+ * A <code>Closure</code> represents a block of code which is executed from
+ * inside some block, function or iteration. It operates an input object.
+ * <p>
+ * Standard implementations of common closures are provided by
+ * {@link ClosureUtils}. These include method invokation and for/while loops.
  *  
  * @since Commons Collections 1.0
- * @version $Revision: 1.10 $ $Date: 2004/02/18 01:15:42 $
+ * @version $Revision: 1.11 $ $Date: 2004/04/14 20:08:56 $
  *
  * @author James Strachan
  * @author Nicola Ken Barozzi
  * @author Stephen Colebourne
  */
 public interface Closure {
-    
+
     /**
      * Performs an action on the specified input object.
      *
@@ -39,5 +42,5 @@ public interface Closure {
      * @throws FunctorException (runtime) if any other error occurs
      */
     public void execute(Object input);
-    
+
 }

src/java/org/apache/commons/collections/Factory.java

@@ -17,15 +17,22 @@ package org.apache.commons.collections;
 
 /**
  * Defines a functor interface implemented by classes that create objects.
+ * <p>
+ * A <code>Factory</code> creates an object without using an input parameter.
+ * If an input parameter is required, then {@link Transformer} is more appropriate.
+ * <p>
+ * Standard implementations of common factories are provided by
+ * {@link FactoryUtils}. These include factories that return a constant,
+ * a copy of a prototype or a new instance.
  * 
  * @since Commons Collections 2.1
- * @version $Revision: 1.8 $ $Date: 2004/02/18 01:15:42 $
+ * @version $Revision: 1.9 $ $Date: 2004/04/14 20:08:57 $
  *
  * @author Arron Bates
  * @author Stephen Colebourne
  */
 public interface Factory {
-    
+
     /**
      * Create a new object.
      *
@@ -33,5 +40,5 @@ public interface Factory {
      * @throws FunctorException (runtime) if the factory cannot create an object
      */
     public Object create();
-    
+
 }

src/java/org/apache/commons/collections/Predicate.java

@@ -16,27 +16,34 @@
 package org.apache.commons.collections;
 
 /**
- * Defines a functor interface implemented by classes that
- * perform a predicate test on an object. Predicate instances can be used
- * to implement queries or to do filtering. 
+ * Defines a functor interface implemented by classes that perform a predicate
+ * test on an object.
+ * <p>
+ * A <code>Predicate</code> is the object equivalent of an <code>if</code> statement.
+ * It uses the input object to return a true or false value, and is often used in
+ * validation or filtering.
+ * <p>
+ * Standard implementations of common predicates are provided by
+ * {@link PredicateUtils}. These include true, false, instanceof, equals, and,
+ * or, not, method invokation and null testing.
  * 
  * @since Commons Collections 1.0
- * @version $Revision: 1.10 $ $Date: 2004/02/18 01:15:42 $
+ * @version $Revision: 1.11 $ $Date: 2004/04/14 20:08:57 $
  * 
  * @author James Strachan
  * @author Stephen Colebourne
  */
 public interface Predicate {
-    
+
     /**
      * Use the specified parameter to perform a test that returns true or false.
      *
-     * @param object  the object to evaluate
+     * @param object  the object to evaluate, should not be changed
      * @return true or false
      * @throws ClassCastException (runtime) if the input is the wrong class
      * @throws IllegalArgumentException (runtime) if the input is invalid
      * @throws FunctorException (runtime) if the predicate encounters a problem
      */
     public boolean evaluate(Object object);
-    
+
 }

src/java/org/apache/commons/collections/Transformer.java

@@ -16,13 +16,20 @@
 package org.apache.commons.collections;
 
 /**
- * Defines a functor interface implemented by classes that
- * transform one object into another. The original object is left unchanged.
+ * Defines a functor interface implemented by classes that transform one
+ * object into another.
+ * <p>
+ * A <code>Transformer</code> converts the input object to the output object.
+ * The input object should be left unchanged.
  * Transformers are typically used for type conversions, or extracting data
  * from an object.
+ * <p>
+ * Standard implementations of common transformers are provided by
+ * {@link TransformerUtils}. These include method invokation, returning a constant,
+ * cloning and returning the string value.
  * 
  * @since Commons Collections 1.0
- * @version $Revision: 1.9 $ $Date: 2004/02/18 01:15:42 $
+ * @version $Revision: 1.10 $ $Date: 2004/04/14 20:08:57 $
  * 
  * @author James Strachan
  * @author Stephen Colebourne
@@ -32,12 +39,12 @@ public interface Transformer {
     /**
      * Transforms the input object (leaving it unchanged) into some output object.
      *
-     * @param input  the object to be transformed
+     * @param input  the object to be transformed, should be left unchanged
      * @return a transformed object
      * @throws ClassCastException (runtime) if the input is the wrong class
      * @throws IllegalArgumentException (runtime) if the input is invalid
      * @throws FunctorException (runtime) if the transform cannot be completed
      */
     public Object transform(Object input);
-    
+
 }