propertyutilsbean.java

一个很好实用的工作流OSWORKFLOW开发例子.有着非常优秀的灵活性.

      }
    }
    // can't find any
    return -1;
  }

  /**
   * <p>Retrieve the property descriptors for the specified class,
   * introspecting and caching them the first time a particular bean class
   * is encountered.</p>
   * <p/>
   * <p><strong>FIXME</strong> - Does not work with DynaBeans.</p>
   *
   * @param beanClass Bean class for which property descriptors are requested
   * @throws IllegalArgumentException if <code>beanClass</code> is null
   */
  public PropertyDescriptor[] getPropertyDescriptors(Class beanClass)
  {

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

    // Look up any cached descriptors for this bean class
    PropertyDescriptor[] descriptors;
    descriptors = (PropertyDescriptor[])descriptorsCache.get(beanClass);
    if(descriptors != null)
    {
      return (descriptors);
    }

    // Introspect the bean and cache the generated descriptors
    BeanInfo beanInfo;
    try
    {
      beanInfo = Introspector.getBeanInfo(beanClass);
    }
    catch(IntrospectionException e)
    {
      return (new PropertyDescriptor[0]);
    }
    descriptors = beanInfo.getPropertyDescriptors();
    if(descriptors == null)
    {
      descriptors = new PropertyDescriptor[0];
    }
    descriptorsCache.put(beanClass, descriptors);
    return (descriptors);

  }

  /**
   * <p>Retrieve the property descriptors for the specified bean,
   * introspecting and caching them the first time a particular bean class
   * is encountered.</p>
   * <p/>
   * <p><strong>FIXME</strong> - Does not work with DynaBeans.</p>
   *
   * @param bean Bean for which property descriptors are requested
   * @throws IllegalArgumentException if <code>bean</code> is null
   */
  public PropertyDescriptor[] getPropertyDescriptors(Object bean)
  {

    if(bean == null)
    {
      throw new IllegalArgumentException("No bean specified");
    }
    return (getPropertyDescriptors(bean.getClass()));

  }

  /**
   * <p>Return the Java Class repesenting the property editor class that has
   * been registered for this property (if any).  This method follows the
   * same name resolution rules used by <code>getPropertyDescriptor()</code>,
   * so if the last element of a name reference is indexed, the property
   * editor for the underlying property's class is returned.</p>
   * <p/>
   * <p>Note that <code>null</code> will be returned if there is no property,
   * or if there is no registered property editor class.  Because this
   * return value is ambiguous, you should determine the existence of the
   * property itself by other means.</p>
   * <p/>
   * <p><strong>FIXME</strong> - Does not work with DynaBeans.</p>
   *
   * @param bean Bean for which a property descriptor is requested
   * @param name Possibly indexed and/or nested name of the property for
   *             which a property descriptor is requested
   * @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 IllegalArgumentException  if a nested reference to a
   *                                   property returns null
   * @throws InvocationTargetException if the property accessor method
   *                                   throws an exception
   * @throws NoSuchMethodException     if an accessor method for this
   *                                   propety cannot be found
   */
  public Class getPropertyEditorClass(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");
    }

    PropertyDescriptor descriptor = getPropertyDescriptor(bean, name);
    if(descriptor != null)
    {
      return (descriptor.getPropertyEditorClass());
    }
    else
    {
      return (null);
    }

  }

  /**
   * Return the Java Class representing the property type of the specified
   * property, or <code>null</code> if there is no such property for the
   * specified bean.  This method follows the same name resolution rules
   * used by <code>getPropertyDescriptor()</code>, so if the last element
   * of a name reference is indexed, the type of the property itself will
   * be returned.  If the last (or only) element has no property with the
   * specified name, <code>null</code> is returned.
   *
   * @param bean Bean for which a property descriptor is requested
   * @param name Possibly indexed and/or nested name of the property for
   *             which a property descriptor is requested
   * @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 IllegalArgumentException  if a nested reference to a
   *                                   property returns null
   * @throws InvocationTargetException if the property accessor method
   *                                   throws an exception
   * @throws NoSuchMethodException     if an accessor method for this
   *                                   propety cannot be found
   */
  public Class getPropertyType(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");
    }

    PropertyDescriptor descriptor = getPropertyDescriptor(bean, name);
    if(descriptor == null)
    {
      return (null);
    }
    else if(descriptor instanceof IndexedPropertyDescriptor)
    {
      return (((IndexedPropertyDescriptor)descriptor).getIndexedPropertyType());
    }
    else if(descriptor instanceof MappedPropertyDescriptor)
    {
      return (((MappedPropertyDescriptor)descriptor).getMappedPropertyType());
    }
    else
    {
      return (descriptor.getPropertyType());
    }

  }

  /**
   * <p>Return an accessible property getter method for this property,
   * if there is one; otherwise return <code>null</code>.</p>
   * <p/>
   * <p><strong>FIXME</strong> - Does not work with DynaBeans.</p>
   *
   * @param descriptor Property descriptor to return a getter for
   */
  public Method getReadMethod(PropertyDescriptor descriptor)
  {

    return (MethodUtils.getAccessibleMethod(descriptor.getReadMethod()));

  }

  /**
   * Return the value of the specified simple property of the specified
   * bean, with no type conversions.
   *
   * @param bean Bean whose property is to be extracted
   * @param name Name of the property to be extracted
   * @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 IllegalArgumentException  if the property name
   *                                   is nested or indexed
   * @throws InvocationTargetException if the property accessor method
   *                                   throws an exception
   * @throws NoSuchMethodException     if an accessor method for this
   *                                   propety cannot be found
   */
  public Object getSimpleProperty(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");
    }

    // Validate the syntax of the property name
    if(name.indexOf(PropertyUtils.NESTED_DELIM) >= 0)
    {
      throw new IllegalArgumentException("Nested property names are not allowed");
    }
    else if(name.indexOf(PropertyUtils.INDEXED_DELIM) >= 0)
    {
      throw new IllegalArgumentException("Indexed property names are not allowed");
    }
    else if(name.indexOf(PropertyUtils.MAPPED_DELIM) >= 0)
    {
      throw new IllegalArgumentException("Mapped property names are not allowed");
    }

    // Retrieve the property getter method for the specified property
    PropertyDescriptor descriptor = getPropertyDescriptor(bean, name);
    if(descriptor == null)
    {
      throw new NoSuchMethodException("Unknown property '" + name + "' in bean " + bean + " of type " + bean.getClass());
    }
    Method readMethod = getReadMethod(descriptor);
    if(readMethod == null)
    {
      throw new NoSuchMethodException("Property '" + name + "' has no getter method");
    }

    // Call the property getter and return the value
    Object value = invokeMethod(readMethod, bean, new Object[0]);
    return (value);

  }

  /**
   * <p>Return an accessible property setter method for this property,
   * if there is one; otherwise return <code>null</code>.</p>
   * <p/>
   * <p><strong>FIXME</strong> - Does not work with DynaBeans.</p>
   *
   * @param descriptor Property descriptor to return a setter for
   */
  public Method getWriteMethod(PropertyDescriptor descriptor)
  {

    return (MethodUtils.getAccessibleMethod(descriptor.getWriteMethod()));

  }

  /**
   * <p>Return <code>true</code> if the specified property name identifies
   * a readable property on the specified bean; otherwise, return
   * <code>false</code>.
   *
   * @param bean Bean to be examined
   * @param name Property name to be evaluated
   * @throws IllegalArgumentException if <code>bean</code>
   *                                  or <code>name</code> is <code>null</code>
   * @since BeanUtils 1.6
   */
  public boolean isReadable(Object bean, String name)
  {

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

    // Return the requested result
    try
    {
      PropertyDescriptor desc = getPropertyDescriptor(bean, name);
      if(desc != null)
      {
        Method readMethod = desc.getReadMethod();
        if((readMethod == null) && (desc instanceof IndexedPropertyDescriptor))
        {
          readMethod = ((IndexedPropertyDescriptor)desc).getIndexedReadMethod();
        }
        return (readMethod != null);
      }
      else
      {
        return (false);
      }
    }
    catch(IllegalAccessException e)
    {
      return (false);
    }
    catch(InvocationTargetException e)
    {
      return (false);
    }
    catch(NoSuchMethodException e)
    {
      return (false);
    }

  }

  /**
   * <p>Return <code>true</code> if the specified property name identifies
   * a writeable property on the specified bean; otherwise, return
   * <code>false</code>.
   *
   * @param bean Bean to be examined
   * @param name Property name to be evaluated
   * @throws IllegalArgumentException if <code>bean</code>
   *                                  or <code>name</code> is <code>null</code>
   * @since BeanUtils 1.6
   */
  public boolean isWriteable(Object bean, String name)
  {

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

    // Return the requested result
    try
    {
      PropertyDescriptor desc = getPropertyDescriptor(bean, name);
      if(desc != null)
      {
        Method writeMethod = desc.getWriteMethod();
        if((writeMethod == null) && (desc instanceof IndexedPropertyDescriptor))
        {
          writeMethod = ((IndexedPropertyDescriptor)desc).getIndexedWriteMethod();
        }
        return (writeMethod != null);
      }
      else
      {
        return (false);
      }
    }
    catch(IllegalAccessException e)
    {
      return (false);
    }
    catch(InvocationTargetException e)
    {
      return (false);
    }
    catch(NoSuchMethodException e)
    {
      return (false);
    }
  }

  /**
   * Set 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 modified
   * @param name  <code>propertyname[index]</code> of the property value
   *              to be modified
   * @param value Value to which the specified property element
   *              should be set
   * @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 void setIndexedProperty(Object bean, String name, Object value) 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;
    try
    {
      String subscript = name.substring(delim + 1, delim2);
      index = Integer.parseInt(subscript);
    }