bayard      2002/11/06 11:15:40

  Added:       lang/src/java/org/apache/commons/lang/functor Executor.java
                        ExecutorException.java ExecutorUtils.java
  Log:
  And a new name. Until it gets changed.
  
  Revision  Changes    Path
  1.1                  
jakarta-commons/lang/src/java/org/apache/commons/lang/functor/Executor.java
  
  Index: Executor.java
  ===================================================================
  /* ====================================================================
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 2002 The Apache Software Foundation.  All rights
   * reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution, if
   *    any, must include the following acknowlegement:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowlegement may appear in the software itself,
   *    if and wherever such third-party acknowlegements normally appear.
   *
   * 4. The names "The Jakarta Project", "Commons", and "Apache Software
   *    Foundation" must not be used to endorse or promote products derived
   *    from this software without prior written permission. For written
   *    permission, please contact [EMAIL PROTECTED]
   *
   * 5. Products derived from this software may not be called "Apache"
   *    nor may "Apache" appear in their names without prior written
   *    permission of the Apache Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   */
  package org.apache.commons.lang.functor;
  
  /**
   * <code>Executor</code> defines an interface implemented by classes that
   * do something.
   *
   * @author <a href="mailto:nicolaken@;apache.org">Nicola Ken Barozzi</a>
   * @version $Id: Executor.java,v 1.1 2002/11/06 19:15:40 bayard Exp $
   */
  public interface Executor {
      
      /**
       * Does what it has to.
       *
       * @param description  the extra information needed to execute the 
       *                     command
       *
       * @throws ExecutorException (runtime) if the execution fails
       */
      public void execute(Object description);
      
  }
  
  
  
  1.1                  
jakarta-commons/lang/src/java/org/apache/commons/lang/functor/ExecutorException.java
  
  Index: ExecutorException.java
  ===================================================================
  /* ====================================================================
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 2002 The Apache Software Foundation.  All rights
   * reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution, if
   *    any, must include the following acknowlegement:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowlegement may appear in the software itself,
   *    if and wherever such third-party acknowlegements normally appear.
   *
   * 4. The names "The Jakarta Project", "Commons", and "Apache Software
   *    Foundation" must not be used to endorse or promote products derived
   *    from this software without prior written permission. For written
   *    permission, please contact [EMAIL PROTECTED]
   *
   * 5. Products derived from this software may not be called "Apache"
   *    nor may "Apache" appear in their names without prior written
   *    permission of the Apache Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   */
  package org.apache.commons.lang.functor;
  
  import org.apache.commons.lang.exception.NestableRuntimeException;
  /**
   * Exception thrown when the Comand fails to execute.
   * If required, a root cause error can be wrapped within this one.
   *
   * @author <a href="mailto:nicolaken@;apache.org">Nicola Ken Barozzi</a>
   * @version $Id: ExecutorException.java,v 1.1 2002/11/06 19:15:40 bayard Exp $
   */
  public class ExecutorException extends NestableRuntimeException {
  
      /**
       * Constructs a new <code>ExecutorException</code> without specified
       * detail message.
       */
      public ExecutorException() {
          super();
      }
  
      /**
       * Constructs a new <code>ExecutorException</code> with specified
       * detail message.
       *
       * @param msg  the error message.
       */
      public ExecutorException(String msg) {
          super(msg);
      }
  
      /**
       * Constructs a new <code>ExecutorException</code> with specified
       * nested <code>Throwable</code> root cause.
       *
       * @param rootCause  the exception or error that caused this exception
       *                   to be thrown.
       */
      public ExecutorException(Throwable rootCause) {
          super(rootCause);
      }
  
      /**
       * Constructs a new <code>ExecutorException</code> with specified
       * detail message and nested <code>Throwable</code> root cause.
       *
       * @param msg        the error message.
       * @param rootCause  the exception or error that caused this exception
       *                   to be thrown.
       */
      public ExecutorException(String msg, Throwable rootCause) {
          super(msg, rootCause);
      }
  
  }
  
  
  
  1.1                  
jakarta-commons/lang/src/java/org/apache/commons/lang/functor/ExecutorUtils.java
  
  Index: ExecutorUtils.java
  ===================================================================
  /* ====================================================================
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 2002 The Apache Software Foundation.  All rights
   * reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution, if
   *    any, must include the following acknowlegement:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowlegement may appear in the software itself,
   *    if and wherever such third-party acknowlegements normally appear.
   *
   * 4. The names "The Jakarta Project", "Commons", and "Apache Software
   *    Foundation" must not be used to endorse or promote products derived
   *    from this software without prior written permission. For written
   *    permission, please contact [EMAIL PROTECTED]
   *
   * 5. Products derived from this software may not be called "Apache"
   *    nor may "Apache" appear in their names without prior written
   *    permission of the Apache Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   */
  package org.apache.commons.lang.functor;
  
  import java.io.Serializable;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.Map;
  
  import org.apache.commons.lang.functor.Predicate;
  import org.apache.commons.lang.functor.PredicateUtils;
  import org.apache.commons.lang.functor.Transformer;
  import org.apache.commons.lang.functor.TransformerException;
  import org.apache.commons.lang.functor.TransformerUtils;
  /**
   * <code>ExecutorUtils</code> provides reference implementations and utilities
   * for the Executor pattern interface. The supplied commands are:
   * <ul>
   * <li>Invoker - invokes a method on the input object
   * <li>For - repeatedly calls a command for a fixed number of times
   * <li>While - repeatedly calls a command while a predicate is true
   * <li>DoWhile - repeatedly calls a command while a predicate is true
   * <li>Chained - chains two or more commands together
   * <li>Switch - calls one command based on one or more predicates
   * <li>SwitchMap - calls one command looked up from a Map
   * <li>Transformer - wraps a Transformer as a Predicate
   * <li>NOP - does nothing
   * <li>Exception - always throws an exception
   * </ul>
   * All the supplied commands are Serializable.
   *
   * @author <a href="mailto:scolebourne@;joda.org">Stephen Colebourne</a>
   * @version $Id: ExecutorUtils.java,v 1.1 2002/11/06 19:15:40 bayard Exp $
   */
  public class ExecutorUtils {
  
      /**
       * A Executor that always throws an exception
       */
      private static final Executor EXCEPTION_COMMAND = new ExceptionExecutor();
      /**
       * A Executor that does nothing
       */
      private static final Executor NOP_COMMAND = new NOPExecutor();
  
      /**
       * Restrictive constructor
       */
      protected ExecutorUtils() {
          super();
      }
  
      /**
       * Gets a Executor that always throws an exception.
       * This could be useful during testing as a placeholder.
       *
       * @return the command
       */
      public static Executor exceptionExecutor() {
          return EXCEPTION_COMMAND;
      }
  
      /**
       * Gets a Executor that will do nothing.
       * This could be useful during testing as a placeholder.
       *
       * @return the command
       */
      public static Executor nopExecutor() {
          return NOP_COMMAND;
      }
  
      /**
       * Creates a Executor that calls a Factory each time the transformer is used.
       * The transformer will return the value returned by the factory.
       *
       * @param transformer  the transformer to run each time in the command
       * @return the command.
       */
      public static Executor asExecutor(Transformer transformer) {
          if (transformer == null) {
              throw new IllegalArgumentException("TransformerExecutor: The transformer 
must not be null");
          }
          return new TransformerExecutor(transformer);
      }
  
      /**
       * Creates a Executor that will call the command <code>count</code> times.
       *
       * @param count  the number of times to loop
       * @param command  the command to call repeatedly
       * @return the command
       * @throws IllegalArgumentException if either argument is null
       */
      public static Executor forExecutor(int count, Executor command) {
          if (count < 0) {
              throw new IllegalArgumentException("ForExecutor: The loop count must not 
be less than zero, it was " + count);
          }
          if (command == null) {
              throw new IllegalArgumentException("ForExecutor: The command must not be 
null");
          }
          return new ForExecutor(count, command);
      }
  
      /**
       * Creates a Executor that will call the command repeatedly until the 
       * predicate returns false.
       *
       * @param predicate  the predicate to use as an end of loop test
       * @param command  the command to call repeatedly
       * @return the command
       * @throws IllegalArgumentException if either argument is null
       */
      public static Executor whileExecutor(Predicate predicate, Executor command) {
          if (predicate == null) {
              throw new IllegalArgumentException("WhileExecutor: The predicate must 
not be null");
          }
          if (command == null) {
              throw new IllegalArgumentException("WhileExecutor: The command must not 
be null");
          }
          return new WhileExecutor(predicate, command, false);
      }
  
      /**
       * Creates a Executor that will call the command once and then repeatedly
       * until the predicate returns false.
       *
       * @param command  the command to call repeatedly
       * @param predicate  the predicate to use as an end of loop test
       * @return the command
       * @throws IllegalArgumentException if either argument is null
       */
      public static Executor doWhileExecutor(Executor command, Predicate predicate) {
          if (command == null) {
              throw new IllegalArgumentException("DoWhileExecutor: The command must 
not be null");
          }
          if (predicate == null) {
              throw new IllegalArgumentException("DoWhileExecutor: The predicate must 
not be null");
          }
          return new WhileExecutor(predicate, command, true);
      }
  
      /**
       * Creates a Executor that will invoke a specific method on the command's
       * input object by reflection.
       *
       * @param methodName  the name of the method
       * @return the command
       * @throws IllegalArgumentException if the method name is null
       */
      public static Executor invokerExecutor(String methodName) {
          return asExecutor(TransformerUtils.invokerTransformer(methodName, null, 
null));
      }
  
      /**
       * Creates a Executor that will invoke a specific method on the command's
       * input object by reflection.
       *
       * @param methodName  the name of the method
       * @param paramTypes  the parameter types
       * @param args  the arguments
       * @return the command
       * @throws IllegalArgumentException if the method name is null
       * @throws IllegalArgumentException if the paramTypes and args don't match
       */
      public static Executor invokerExecutor(String methodName, Class[] paramTypes, 
Object[] args) {
          return asExecutor(TransformerUtils.invokerTransformer(methodName, 
paramTypes, args));
      }
  
      /**
       * Create a new Executor that calls two Executors, passing the result of
       * the first into the second.
       * 
       * @param command1  the first command
       * @param command2  the second command
       * @return the command
       * @throws IllegalArgumentException if either command is null
       */
      public static Executor chainedExecutor(Executor command1, Executor command2) {
          Executor[] commands = new Executor[] { command1, command2 };
          validate(commands);
          return new ChainedExecutor(commands);
      }
  
      /**
       * Create a new Executor that calls each command in turn, passing the 
       * result into the next command.
       * 
       * @param commands  an array of commands to chain
       * @return the command
       * @throws IllegalArgumentException if the commands array is null
       * @throws IllegalArgumentException if the commands array has 0 elements
       * @throws IllegalArgumentException if any command in the array is null
       */
      public static Executor chainedExecutor(Executor[] commands) {
          commands = copy(commands);
          validate(commands);
          return new ChainedExecutor(commands);
      }
  
      /**
       * Create a new Executor that calls each command in turn, passing the 
       * result into the next command. The ordering is that of the iterator()
       * method on the collection.
       * 
       * @param commands  a collection of commands to chain
       * @return the command
       * @throws IllegalArgumentException if the commands collection is null
       * @throws IllegalArgumentException if the commands collection is empty
       * @throws IllegalArgumentException if any command in the collection is null
       */
      public static Executor chainedExecutor(Collection commands) {
          if (commands == null) {
              throw new IllegalArgumentException("ChainedExecutor: The command 
collection must not be null");
          }
          // convert to array like this to guarantee iterator() ordering
          Executor[] cmds = new Executor[commands.size()];
          int i = 0;
          for (Iterator it = commands.iterator(); it.hasNext();) {
              cmds[i++] = (Executor) it.next();
          }
          validate(cmds);
          return new ChainedExecutor(cmds);
      }
  
      /**
       * Create a new Executor that calls one of two commands depending 
       * on the specified predicate.
       * 
       * @param predicate  the predicate to switch on
       * @param trueExecutor  the command called if the predicate is true
       * @param falseExecutor  the command called if the predicate is false
       * @return the command
       * @throws IllegalArgumentException if the predicate is null
       * @throws IllegalArgumentException if either command is null
       */
      public static Executor switchExecutor(Predicate predicate, Executor 
trueExecutor, Executor falseExecutor) {
          return switchExecutorInternal(new Predicate[] { predicate }, new Executor[] 
{ trueExecutor }, falseExecutor);
      }
  
      /**
       * Create a new Executor that calls one of the commands depending 
       * on the predicates. The command at array location 0 is called if the
       * predicate at array location 0 returned true. Each predicate is evaluated
       * until one returns true.
       * 
       * @param predicates  an array of predicates to check
       * @param commands  an array of commands to call
       * @return the command
       * @throws IllegalArgumentException if the either array is null
       * @throws IllegalArgumentException if the either array has 0 elements
       * @throws IllegalArgumentException if any element in the arrays is null
       * @throws IllegalArgumentException if the arrays are different sizes
       */
      public static Executor switchExecutor(Predicate[] predicates, Executor[] 
commands) {
          return switchExecutorInternal(copy(predicates), copy(commands), null);
      }
  
      /**
       * Create a new Executor that calls one of the commands depending 
       * on the predicates. The command at array location 0 is called if the
       * predicate at array location 0 returned true. Each predicate is evaluated
       * until one returns true. If no predicates evaluate to true, the default
       * command is called.
       * 
       * @param predicates  an array of predicates to check
       * @param commands  an array of commands to call
       * @param defaultExecutor  the default to call if no predicate matches
       * @return the command
       * @throws IllegalArgumentException if the either array is null
       * @throws IllegalArgumentException if the either array has 0 elements
       * @throws IllegalArgumentException if any element in the arrays is null
       * @throws IllegalArgumentException if the arrays are different sizes
       */
      public static Executor switchExecutor(Predicate[] predicates, Executor[] 
commands, Executor defaultExecutor) {
          return switchExecutorInternal(copy(predicates), copy(commands), 
defaultExecutor);
      }
      
      /**
       * Create a new Executor that calls one of the commands depending 
       * on the predicates. 
       * <p>
       * The Map consists of Predicate keys and Executor values. A command 
       * is called if its matching predicate returns true. Each predicate is evaluated
       * until one returns true. If no predicates evaluate to true, the default
       * command is called. The default command is set in the map with a 
       * null key. The ordering is that of the iterator() method on the entryset 
       * collection of the map.
       * 
       * @param predicatesAndExecutors  a map of predicates to commands
       * @return the command
       * @throws IllegalArgumentException if the map is null
       * @throws IllegalArgumentException if the map is empty
       * @throws IllegalArgumentException if any command in the map is null
       * @throws ClassCastException  if the map elements are of the wrong type
       */
      public static Executor switchExecutor(Map predicatesAndExecutors) {
          Executor[] trs = null;
          Predicate[] preds = null;
          if (predicatesAndExecutors == null) {
              throw new IllegalArgumentException("SwitchExecutor: The predicate and 
command map must not be null");
          }
          // convert to array like this to guarantee iterator() ordering
          Executor def = (Executor) predicatesAndExecutors.remove(null);
          int size = predicatesAndExecutors.size();
          trs = new Executor[size];
          preds = new Predicate[size];
          int i = 0;
          for (Iterator it = predicatesAndExecutors.entrySet().iterator(); 
it.hasNext();) {
              Map.Entry entry = (Map.Entry) it.next();
              preds[i] = (Predicate) entry.getKey();
              trs[i] = (Executor) entry.getValue();
              i++;
          }
          return switchExecutorInternal(preds, trs, def);
      }
  
      /**
       * Validate input and create command
       */
      private static Executor switchExecutorInternal(Predicate[] predicates, 
Executor[] commands, Executor defaultExecutor) {
          validate(predicates);
          validate(commands);
          if (predicates.length != commands.length) {
              throw new IllegalArgumentException("SwitchExecutor: The predicate and 
command arrays must be the same size");
          }
          if (defaultExecutor == null) {
              defaultExecutor = nopExecutor();
          }
          return new SwitchExecutor(predicates, commands, defaultExecutor);
      }
  
      /**
       * Create a new Executor that uses the input object as a key to find the
       * command to call. 
       * <p>
       * The Map consists of object keys and Executor values. A command 
       * is called if the input object equals the key. If there is no match, the
       * default command is called. The default command is set in the map
       * using a null key.
       * 
       * @param objectsAndExecutors  a map of objects to commands
       * @return the command
       * @throws IllegalArgumentException if the map is null
       * @throws IllegalArgumentException if the map is empty
       * @throws IllegalArgumentException if any command in the map is null
       */
      public static Executor switchMapExecutor(Map objectsAndExecutors) {
          Executor[] trs = null;
          Predicate[] preds = null;
          if (objectsAndExecutors == null) {
              throw new IllegalArgumentException("SwitchEqualsExecutor: The obejct and 
command map must not be null");
          }
          Executor def = (Executor) objectsAndExecutors.remove(null);
          int size = objectsAndExecutors.size();
          trs = new Executor[size];
          preds = new Predicate[size];
          int i = 0;
          for (Iterator it = objectsAndExecutors.entrySet().iterator(); it.hasNext();) 
{
              Map.Entry entry = (Map.Entry) it.next();
              preds[i] = PredicateUtils.equalPredicate(entry.getKey());
              trs[i] = (Executor) entry.getValue();
              i++;
          }
          return switchExecutor(preds, trs, def);
      }
  
      /**
       * Copy method
       * 
       * @param predicates  the predicates to copy
       */
      private static Predicate[] copy(Predicate[] predicates) {
          if (predicates == null) {
              return null;
          }
          return (Predicate[]) predicates.clone();
      }
      
      /**
       * Validate method
       * 
       * @param predicates  the predicates to validate
       */
      private static void validate(Predicate[] predicates) {
          if (predicates == null) {
              throw new IllegalArgumentException("ExecutorUtils: The predicate array 
must not be null");
          }
          if (predicates.length < 1) {
              throw new IllegalArgumentException(
                  "ExecutorUtils: At least 1 predicate must be specified in the 
predicate array, size was " + predicates.length);
          }
          for (int i = 0; i < predicates.length; i++) {
              if (predicates[i] == null) {
                  throw new IllegalArgumentException("ExecutorUtils: The predicate 
array must not contain a null predicate, index " + i + " was null");
              }
          }
      }
  
      /**
       * Copy method
       * 
       * @param commands  the commands to copy
       */
      private static Executor[] copy(Executor[] commands) {
          if (commands == null) {
              return null;
          }
          return (Executor[]) commands.clone();
      }
      
      /**
       * Validate method
       * 
       * @param commands  the commands to validate
       */
      private static void validate(Executor[] commands) {
          if (commands == null) {
              throw new IllegalArgumentException("ExecutorUtils: The command array 
must not be null");
          }
          if (commands.length < 1) {
              throw new IllegalArgumentException(
                  "ExecutorUtils: At least 1 command must be specified in the command 
array, size was " + commands.length);
          }
          for (int i = 0; i < commands.length; i++) {
              if (commands[i] == null) {
                  throw new IllegalArgumentException("ExecutorUtils: The command array 
must not contain a null command, index " + i + " was null");
              }
          }
      }
  
      // ExceptionExecutor
      
//----------------------------------------------------------------------------------
  
      /**
       * ExceptionExecutor always throws an exception
       */
      private static class ExceptionExecutor implements Executor, Serializable {
  
          /**
           * Constructor
           */
          private ExceptionExecutor() {
              super();
          }
  
          /**
           * Always throw an exception
           */
          public void execute(Object input) {
              throw new ExecutorException("ExceptionExecutor invoked");
          }
      }
  
      // NOPExecutor
      
//----------------------------------------------------------------------------------
  
      /**
       * NOPExecutor does nothing
       */
      private static class NOPExecutor implements Executor, Serializable {
  
          /**
           * Constructor
           */
          private NOPExecutor() {
              super();
          }
  
          /**
           * Do nothing
           */
          public void execute(Object input) {
              // do nothing
          }
      }
  
      // TransformerExecutor
      
//----------------------------------------------------------------------------------
  
      /**
       * TransformerExecutor returns the result of calling a Transformer.
       */
      private static class TransformerExecutor implements Executor, Serializable {
  
          private final Transformer iTransformer;
  
          /**
           * Constructor to store factory
           */
          private TransformerExecutor(Transformer transformer) {
              super();
              iTransformer = transformer;
          }
  
          /**
           * Return the result of calling the factory
           */
          public void execute(Object input) {
              try {
                  iTransformer.transform(input);
  
              } catch (TransformerException ex) {
                  throw new ExecutorException("TransformerExecutor: " + 
ex.getMessage(), ex);
              }
          }
      }
  
      // ChainedExecutor
      
//----------------------------------------------------------------------------------
  
      /**
       * ChainedExecutor calls a list of commands.
       */
      private static class ChainedExecutor implements Executor, Serializable {
  
          private final Executor[] iExecutors;
  
          /**
           * Constructor to store params
           */
          private ChainedExecutor(Executor[] commands) {
              super();
              iExecutors = commands;
          }
  
          /**
           * Execute a list of commands
           */
          public void execute(Object input) {
              for (int i = 0; i < iExecutors.length; i++) {
                  iExecutors[i].execute(input);
              }
          }
      }
  
      // SwitchExecutor
      
//----------------------------------------------------------------------------------
  
      /**
       * SwitchExecutor calls the command whose predicate returns true.
       */
      private static class SwitchExecutor implements Executor, Serializable {
  
          private final Predicate[] iPredicates;
          private final Executor[] iExecutors;
          private final Executor iDefault;
  
          /**
           * Constructor to store params
           */
          private SwitchExecutor(Predicate[] predicates, Executor[] commands, Executor 
defaultExecutor) {
              super();
              iPredicates = predicates;
              iExecutors = commands;
              iDefault = defaultExecutor;
          }
  
          /**
           * Execute the command whose predicate returns true
           */
          public void execute(Object input) {
              for (int i = 0; i < iPredicates.length; i++) {
                  if (iPredicates[i].evaluate(input) == true) {
                      iExecutors[i].execute(input);
                      return;
                  }
              }
              iDefault.execute(input);
          }
      }
  
      // ForExecutor
      
//----------------------------------------------------------------------------------
  
      /**
       * ForExecutor calls the command a fixed nunmber of times.
       */
      private static class ForExecutor implements Executor, Serializable {
  
          private final int iCount;
          private final Executor iExecutor;
  
          /**
           * Constructor to store params
           */
          private ForExecutor(int count, Executor command) {
              super();
              iCount = count;
              iExecutor = command;
          }
  
          /**
           * Execute the command count times
           */
          public void execute(Object input) {
              for (int i = 0; i < iCount; i++) {
                  iExecutor.execute(input);
              }
          }
      }
  
      // WhileExecutor
      
//----------------------------------------------------------------------------------
  
      /**
       * WhileExecutor calls the command until the predicate is false.
       */
      private static class WhileExecutor implements Executor, Serializable {
  
          private final Predicate iPredicate;
          private final Executor iExecutor;
          private final boolean iDoLoop;
  
          /**
           * Constructor to store params
           */
          private WhileExecutor(Predicate predicate, Executor command, boolean doLoop) 
{
              super();
              iPredicate = predicate;
              iExecutor = command;
              iDoLoop = doLoop;
          }
  
          /**
           * Execute the command until the predicate is false
           */
          public void execute(Object input) {
              if (iDoLoop) {
                  iExecutor.execute(input);
              }
              while (iPredicate.evaluate(input)) {
                  iExecutor.execute(input);
              }
          }
      }
  
  }
  
  
  

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