xmlpropertydescriptor.java

Novocode的 SWT 控件框架 丰富了MDI功能

/*******************************************************************************
 * Copyright (c) 2004 Stefan Zeiger and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.novocode.com/legal/epl-v10.html
 * 
 * Contributors:
 *     Stefan Zeiger ([e-mail]) - initial API and implementation
 *******************************************************************************/

package com.novocode.naf.data;

import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import com.novocode.naf.app.NAFException;


/**
 * A descriptor for an XMLProperty.
 *
 * @author Stefan Zeiger ([e-mail])
 * @since Dec 17, 2004
 * @version $Id: XMLPropertyDescriptor.java,v 1.1 2004/12/19 00:11:20 szeiger Exp $
 */

public final class XMLPropertyDescriptor
{
  private final Method getter, setter;
  private final IDataConverter conv;
  private final Class propertyType;
  private final String xmlPropertyName;


  public XMLPropertyDescriptor(PropertyDescriptor pd, XMLProperty p)
  {
    String xname = p.value();
    if(xname == null || xname.length() == 0) xname = pd.getName();
    xmlPropertyName = xname;
    setter = pd.getWriteMethod();
    getter = pd.getReadMethod();
    propertyType = pd.getPropertyType();
    if(propertyType == String[].class)
      conv = StringArrayDataConverter.getDefaultInstance();
    else
      conv = DefaultDataConverter.getInstance();
  }
  
  
  public Method getReadMethod() { return getter; }
  
  
  public Method getWriteMethod() { return setter; }
  
  
  public String getXMLPropertyName() { return xmlPropertyName; }


  public void set(Object target, String value) throws NAFException
  {
    if(setter == null) throw new NAFException("Property "+xmlPropertyName+" is read-only");
    try
    {
      setter.invoke(target, new Object[] { conv.toInternal(propertyType, value) });
    }
    catch(InvocationTargetException ex)
    {
      Throwable cause = ex.getCause();
      if(cause instanceof RuntimeException) throw (RuntimeException)cause;
      else throw new NAFException("Error invoking setter method for property "+target.getClass().getName()+":"+xmlPropertyName+": "+ex, ex);
    }
    catch(Exception ex)
    {
      throw new NAFException("Error converting data for property "+target.getClass().getName()+":"+xmlPropertyName+": "+ex, ex);
    }
  }


  public String get(Object target) throws NAFException
  {
    if(getter == null) throw new NAFException("Property "+xmlPropertyName+" is write-only");
    try
    {
      return conv.toExternal(propertyType, getter.invoke(target, new Object[0]));
    }
    catch(InvocationTargetException ex)
    {
      Throwable cause = ex.getCause();
      if(cause instanceof RuntimeException) throw (RuntimeException)cause;
      else throw new NAFException("Error invoking getter method for property "+target.getClass().getName()+":"+xmlPropertyName+": "+ex, ex);
    }
    catch(Exception ex)
    {
      throw new NAFException("Error converting data for property "+target.getClass().getName()+":"+xmlPropertyName+": "+ex, ex);
    }
  }
}