mappedpropertydescriptor.java

osworkflow修改版本

/*
 * $Header: /cvs/osworkflow/src/designer/com/opensymphony/workflow/designer/beanutils/MappedPropertyDescriptor.java,v 1.1 2003/12/06 18:05:58 hani Exp $
 * $Revision: 1.1 $
 * $Date: 2003/12/06 18:05:58 $
 *
 * ====================================================================
 *
 * 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
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 *    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.
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 * 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].
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 * 5. Products derived from this software may not be called "Apache",
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package com.opensymphony.workflow.designer.beanutils;

import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.security.AccessController;
import java.security.PrivilegedAction;

/**
 * A MappedPropertyDescriptor describes one mapped property.
 * Mapped properties are multivalued properties like indexed properties
 * but that are accessed with a String key instead of an index.
 * Such property values are typically stored in a Map collection.
 * For this class to work properly, a mapped value must have
 * getter and setter methods of the form
 * <p><code>get<strong>Property</strong>(String key)<code> and
 * <p><code>set&ltProperty&gt(String key, Object value)<code>,
 * <p>where <code><strong>Property</strong></code> must be replaced
 * by the name of the property.
 *
 * @author Rey Fran鏾is
 * @author Gregor Ra齧an
 * @version $Revision: 1.1 $ $Date: 2003/12/06 18:05:58 $
 * @see java.beans.PropertyDescriptor
 */

public class MappedPropertyDescriptor extends PropertyDescriptor
{
  // ----------------------------------------------------- Instance Variables

  /** The underlying data type of the property we are describing. */
  private Class mappedPropertyType;

  /** The reader method for this property (if any). */
  private Method mappedReadMethod;

  /** The writer method for this property (if any). */
  private Method mappedWriteMethod;

  /** The parameter types array for the reader method signature. */
  private static final Class[] stringClassArray = new Class[]{String.class};

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

  /**
   * Constructs a MappedPropertyDescriptor for a property that follows
   * the standard Java convention by having getFoo and setFoo
   * accessor methods, with the addition of a String parameter (the key).
   * Thus if the argument name is "fred", it will
   * assume that the writer method is "setFred" and the reader method
   * is "getFred".  Note that the property name should start with a lower
   * case character, which will be capitalized in the method names.
   *
   * @param propertyName The programmatic name of the property.
   * @param beanClass    The Class object for the target bean.  For
   *                     example sun.beans.OurButton.class.
   * @throws IntrospectionException if an exception occurs during
   *                                introspection.
   */
  public MappedPropertyDescriptor(String propertyName, Class beanClass) throws IntrospectionException
  {

    super(propertyName, null, null);

    if(propertyName == null || propertyName.length() == 0)
    {
      throw new IntrospectionException("bad property name: " + propertyName + " on class: " + beanClass.getClass().getName());
    }

    setName(propertyName);
    String base = capitalizePropertyName(propertyName);

    // Look for mapped read method and matching write method
    try
    {
      mappedReadMethod = findMethod(beanClass, "get" + base, 1, stringClassArray);
      Class params[] = {String.class, mappedReadMethod.getReturnType()};
      mappedWriteMethod = findMethod(beanClass, "set" + base, 2, params);
    }
    catch(IntrospectionException e)
    {
      ;
    }

    // If there's no read method, then look for just a write method
    if(mappedReadMethod == null)
    {
      mappedWriteMethod = findMethod(beanClass, "set" + base, 2);
    }

    if((mappedReadMethod == null) && (mappedWriteMethod == null))
    {
      throw new IntrospectionException("Property '" + propertyName + "' not found on " + beanClass.getName());
    }

    findMappedPropertyType();
  }

  /**
   * This constructor takes the name of a mapped property, and method
   * names for reading and writing the property.
   *
   * @param propertyName     The programmatic name of the property.
   * @param beanClass        The Class object for the target bean.  For
   *                         example sun.beans.OurButton.class.
   * @param mappedGetterName The name of the method used for
   *                         reading one of the property values.  May be null if the
   *                         property is write-only.
   * @param mappedSetterName The name of the method used for writing
   *                         one of the property values.  May be null if the property is
   *                         read-only.
   * @throws IntrospectionException if an exception occurs during
   *                                introspection.
   */
  public MappedPropertyDescriptor(String propertyName, Class beanClass, String mappedGetterName, String mappedSetterName) throws IntrospectionException
  {

    super(propertyName, null, null);

    if(propertyName == null || propertyName.length() == 0)
    {
      throw new IntrospectionException("bad property name: " + propertyName);
    }
    setName(propertyName);

    // search the mapped get and set methods
    mappedReadMethod = findMethod(beanClass, mappedGetterName, 1, stringClassArray);

    if(mappedReadMethod != null)
    {
      Class params[] = {String.class, mappedReadMethod.getReturnType()};
      mappedWriteMethod = findMethod(beanClass, mappedSetterName, 2, params);
    }
    else
    {
      mappedWriteMethod = findMethod(beanClass, mappedSetterName, 2);
    }

    findMappedPropertyType();
  }

  /**
   * This constructor takes the name of a mapped property, and Method
   * objects for reading and writing the property.
   *
   * @param propertyName The programmatic name of the property.
   * @param mappedGetter The method used for reading one of
   *                     the property values.  May be be null if the property
   *                     is write-only.
   * @param mappedSetter The method used for writing one the
   *                     property values.  May be null if the property is read-only.
   * @throws IntrospectionException if an exception occurs during
   *                                introspection.
   */
  public MappedPropertyDescriptor(String propertyName, Method mappedGetter, Method mappedSetter) throws IntrospectionException
  {

    super(propertyName, mappedGetter, mappedSetter);

    if(propertyName == null || propertyName.length() == 0)
    {
      throw new IntrospectionException("bad property name: " + propertyName);
    }

    setName(propertyName);
    mappedReadMethod = mappedGetter;
    mappedWriteMethod = mappedSetter;
    findMappedPropertyType();
  }

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

  /**
   * Gets the Class object for the property values.
   *
   * @return The Java type info for the property values.  Note that
   *         the "Class" object may describe a built-in Java type such as "int".
   *         The result may be "null" if this is a mapped property that
   *         does not support non-keyed access.
   *         <p/>
   *         This is the type that will be returned by the mappedReadMethod.
   */
  public Class getMappedPropertyType()
  {
    return mappedPropertyType;
  }

  /**
   * Gets the method that should be used to read one of the property value.
   *
   * @return The method that should be used to read the property value.
   *         May return null if the property can't be read.
   */
  public Method getMappedReadMethod()
  {
    return mappedReadMethod;
  }

  /**
   * Sets the method that should be used to read one of the property value.
   *
   * @param mappedGetter The new getter method.
   */
  public void setMappedReadMethod(Method mappedGetter) throws IntrospectionException
  {
    mappedReadMethod = mappedGetter;
    findMappedPropertyType();
  }

  /**
   * Gets the method that should be used to write one of the property value.
   *
   * @return The method that should be used to write one of the property value.
   *         May return null if the property can't be written.
   */
  public Method getMappedWriteMethod()
  {
    return mappedWriteMethod;
  }

  /**
   * Sets the method that should be used to write the property value.
   *
   * @param mappedSetter The new setter method.
   */
  public void setMappedWriteMethod(Method mappedSetter) throws IntrospectionException
  {
    mappedWriteMethod = mappedSetter;
    findMappedPropertyType();
  }

  // ------------------------------------------------------- Private Methods

  /**
   * Introspect our bean class to identify the corresponding getter
   * and setter methods.