propertyutilsbean.java

osworkflow修改版本

/*
 * $Header: /cvs/osworkflow/src/designer/com/opensymphony/workflow/designer/beanutils/PropertyUtilsBean.java,v 1.3 2004/04/16 10:36:29 hani Exp $
 * $Revision: 1.3 $
 * $Date: 2004/04/16 10:36:29 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001-2003 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 acknowledgement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements normally appear.
 *
 * 4. The names "Apache", "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 [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
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 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
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 * 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
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package com.opensymphony.workflow.designer.beanutils;

import java.beans.*;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.*;

/**
 * Utility methods for using Java Reflection APIs to facilitate generic
 * property getter and setter operations on Java objects.  Much of this
 * code was originally included in <code>BeanUtils</code>, but has been
 * separated because of the volume of code involved.
 * <p/>
 * In general, the objects that are examined and modified using these
 * methods are expected to conform to the property getter and setter method
 * naming conventions described in the JavaBeans Specification (Version 1.0.1).
 * No data type conversions are performed, and there are no usage of any
 * <code>PropertyEditor</code> classes that have been registered, although
 * a convenient way to access the registered classes themselves is included.
 * <p/>
 * For the purposes of this class, five formats for referencing a particular
 * property value of a bean are defined, with the layout of an identifying
 * String in parentheses:
 * <ul>
 * <li><strong>Simple (<code>name</code>)</strong> - The specified
 * <code>name</code> identifies an individual property of a particular
 * JavaBean.  The name of the actual getter or setter method to be used
 * is determined using standard JavaBeans instrospection, so that (unless
 * overridden by a <code>BeanInfo</code> class, a property named "xyz"
 * will have a getter method named <code>getXyz()</code> or (for boolean
 * properties only) <code>isXyz()</code>, and a setter method named
 * <code>setXyz()</code>.</li>
 * <li><strong>Nested (<code>name1.name2.name3</code>)</strong> The first
 * name element is used to select a property getter, as for simple
 * references above.  The object returned for this property is then
 * consulted, using the same approach, for a property getter for a
 * property named <code>name2</code>, and so on.  The property value that
 * is ultimately retrieved or modified is the one identified by the
 * last name element.</li>
 * <li><strong>Indexed (<code>name[index]</code>)</strong> - The underlying
 * property value is assumed to be an array, or this JavaBean is assumed
 * to have indexed property getter and setter methods.  The appropriate
 * (zero-relative) entry in the array is selected.  <code>List</code>
 * objects are now also supported for read/write.  You simply need to define
 * a getter that returns the <code>List</code></li>
 * <li><strong>Mapped (<code>name(key)</code>)</strong> - The JavaBean
 * is assumed to have an property getter and setter methods with an
 * additional attribute of type <code>java.lang.String</code>.</li>
 * <li><strong>Combined (<code>name1.name2[index].name3(key)</code>)</strong> -
 * Combining mapped, nested, and indexed references is also
 * supported.</li>
 * </ul>
 *
 * @author Craig R. McClanahan
 * @author Ralph Schaer
 * @author Chris Audley
 * @author Rey Fran鏾is
 * @author Gregor Ra齧an
 * @author Jan Sorensen
 * @author Scott Sanders
 * @version $Revision: 1.3 $ $Date: 2004/04/16 10:36:29 $
 * @see PropertyUtils
 * @since 1.7
 */

public class PropertyUtilsBean
{

  private static final PropertyUtilsBean instance = new PropertyUtilsBean();

  // --------------------------------------------------------- Class Methods

  protected static PropertyUtilsBean getInstance()
  {
    return instance;
  }

  // --------------------------------------------------------- Variables

  /**
   * The cache of PropertyDescriptor arrays for beans we have already
   * introspected, keyed by the java.lang.Class of this object.
   */
  private Map descriptorsCache = null;
  private Map mappedDescriptorsCache = null;

  // ---------------------------------------------------------- Constructors

  /**
   * Base constructor
   */
  public PropertyUtilsBean()
  {
    descriptorsCache = new HashMap();
    mappedDescriptorsCache = new HashMap();
  }


  // --------------------------------------------------------- Public Methods


  /**
   * Clear any cached property descriptors information for all classes
   * loaded by any class loaders.  This is useful in cases where class
   * loaders are thrown away to implement class reloading.
   */
  public void clearDescriptors()
  {

    descriptorsCache.clear();
    mappedDescriptorsCache.clear();
    Introspector.flushCaches();

  }

  /**
   * <p>Copy property values from the "origin" bean to the "destination" bean
   * for all cases where the property names are the same (even though the
   * actual getter and setter methods might have been customized via
   * <code>BeanInfo</code> classes).  No conversions are performed on the
   * actual property values -- it is assumed that the values retrieved from
   * the origin bean are assignment-compatible with the types expected by
   * the destination bean.</p>
   * <p/>
   * <p>If the origin "bean" is actually a <code>Map</code>, it is assumed
   * to contain String-valued <strong>simple</strong> property names as the keys, pointing
   * at the corresponding property values that will be set in the destination
   * bean.<strong>Note</strong> that this method is intended to perform
   * a "shallow copy" of the properties and so complex properties
   * (for example, nested ones) will not be copied.</p>
   *
   * @param dest Destination bean whose properties are modified
   * @param orig Origin bean whose properties are retrieved
   * @throws IllegalAccessException    if the caller does not have
   *                                   access to the property accessor method
   * @throws IllegalArgumentException  if the <code>dest</code> or
   *                                   <code>orig</code> argument is null
   * @throws InvocationTargetException if the property accessor method
   *                                   throws an exception
   * @throws NoSuchMethodException     if an accessor method for this
   *                                   propety cannot be found
   */
  public void copyProperties(Object dest, Object orig) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException
  {

    if(dest == null)
    {
      throw new IllegalArgumentException("No destination bean specified");
    }
    if(orig == null)
    {
      throw new IllegalArgumentException("No origin bean specified");
    }
    if(orig instanceof Map)
    {
      Iterator names = ((Map)orig).keySet().iterator();
      while(names.hasNext())
      {
        String name = (String)names.next();
        if(isWriteable(dest, name))
        {
          Object value = ((Map)orig).get(name);
          setSimpleProperty(dest, name, value);
        }
      }
    }
    else /* if (orig is a standard JavaBean) */
    {
      PropertyDescriptor origDescriptors[] = getPropertyDescriptors(orig);
      for(int i = 0; i < origDescriptors.length; i++)
      {
        String name = origDescriptors[i].getName();
        if(isReadable(orig, name))
        {
          if(isWriteable(dest, name))
          {
            Object value = getSimpleProperty(orig, name);
            setSimpleProperty(dest, name, value);
          }
        }
      }
    }

  }

  /**
   * <p>Return the entire set of properties for which the specified bean
   * provides a read method.  This map contains the unconverted property
   * values for all properties for which a read method is provided
   * (i.e. where the <code>getReadMethod()</code> returns non-null).</p>
   * <p/>
   * <p><strong>FIXME</strong> - Does not account for mapped properties.</p>
   *
   * @param bean Bean whose properties are to be extracted
   * @throws IllegalAccessException    if the caller does not have
   *                                   access to the property accessor method
   * @throws IllegalArgumentException  if <code>bean</code> is null
   * @throws InvocationTargetException if the property accessor method
   *                                   throws an exception
   * @throws NoSuchMethodException     if an accessor method for this
   *                                   propety cannot be found
   */
  public Map describe(Object bean) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException
  {

    if(bean == null)
    {
      throw new IllegalArgumentException("No bean specified");
    }
    Map description = new HashMap();
    PropertyDescriptor descriptors[] = getPropertyDescriptors(bean);
    for(int i = 0; i < descriptors.length; i++)
    {
      String name = descriptors[i].getName();
      if(descriptors[i].getReadMethod() != null)
        description.put(name, getProperty(bean, name));
    }
    return (description);

  }

  /**
   * Return the value of the specified indexed property of the specified
   * bean, with no type conversions.  The zero-relative index of the
   * required value must be included (in square brackets) as a suffix to
   * the property name, or <code>IllegalArgumentException</code> will be
   * thrown.  In addition to supporting the JavaBeans specification, this
   * method has been extended to support <code>List</code> objects as well.
   *
   * @param bean Bean whose property is to be extracted
   * @param name <code>propertyname[index]</code> of the property value
   *             to be extracted
   * @throws ArrayIndexOutOfBoundsException if the specified index
   *                                        is outside the valid range for the underlying array
   * @throws IllegalAccessException         if the caller does not have
   *                                        access to the property accessor method
   * @throws IllegalArgumentException       if <code>bean</code> or
   *                                        <code>name</code> is null
   * @throws InvocationTargetException      if the property accessor method
   *                                        throws an exception
   * @throws NoSuchMethodException          if an accessor method for this
   *                                        propety cannot be found
   */
  public Object getIndexedProperty(Object bean, String name) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException
  {

    if(bean == null)
    {
      throw new IllegalArgumentException("No bean specified");
    }
    if(name == null)
    {
      throw new IllegalArgumentException("No name specified");
    }

    // Identify the index of the requested individual property
    int delim = name.indexOf(PropertyUtils.INDEXED_DELIM);
    int delim2 = name.indexOf(PropertyUtils.INDEXED_DELIM2);
    if((delim < 0) || (delim2 <= delim))
    {
      throw new IllegalArgumentException("Invalid indexed property '" + name + "'");
    }
    int index = -1;
    try
    {
      String subscript = name.substring(delim + 1, delim2);
      index = Integer.parseInt(subscript);
    }
    catch(NumberFormatException e)
    {
      throw new IllegalArgumentException("Invalid indexed property '" + name + "'");
    }
    name = name.substring(0, delim);

    // Request the specified indexed property value
    return (getIndexedProperty(bean, name, index));

  }

  /**
   * Return the value of the specified indexed property of the specified
   * bean, with no type conversions.  In addition to supporting the JavaBeans
   * specification, this method has been extended to support
   * <code>List</code> objects as well.
   *
   * @param bean  Bean whose property is to be extracted