用Introspector提取BeanInfo[Java编程]

//: BeanDumper.java
// A method to introspect a Bean
import java.beans.*;
import java.lang.reflect.*;

public class BeanDumper {
  public static void dump(Class bean){
    BeanInfo bi = null;
    try {
      bi = Introspector.getBeanInfo(
        bean, java.lang.Object.class);
    } catch(IntrospectionException ex) {
      System.out.println("Couldn't introspect " +
        bean.getName());
      System.exit(1);
    }
    PropertyDescriptor[] properties = 
      bi.getPropertyDescriptors();
    for(int i = 0; i < properties.length; i++) {
      Class p = properties[i].getPropertyType();
      System.out.println(
        "Property type:\n  " + p.getName());
      System.out.println(
        "Property name:\n  " + 
        properties[i].getName());
      Method readMethod = 
        properties[i].getReadMethod();
      if(readMethod != null)
        System.out.println(
          "Read method:\n  " + 
          readMethod.toString());
      Method writeMethod = 
        properties[i].getWriteMethod();
      if(writeMethod != null)
        System.out.println(
          "Write method:\n  " +
          writeMethod.toString());
      System.out.println("====================");
    }
    System.out.println("Public methods:");
    MethodDescriptor[] methods =
      bi.getMethodDescriptors();
    for(int i = 0; i < methods.length; i++)
      System.out.println(
        methods[i].getMethod().toString());
    System.out.println("======================");
    System.out.println("Event support:");
    EventSetDescriptor[] events = 
      bi.getEventSetDescriptors();
    for(int i = 0; i < events.length; i++) {
      System.out.println("Listener type:\n  " +
        events[i].getListenerType().getName());
      Method[] lm = 
        events[i].getListenerMethods();
      for(int j = 0; j < lm.length; j++)
        System.out.println(
          "Listener method:\n  " +
          lm[j].getName());
      MethodDescriptor[] lmd = 
        events[i].getListenerMethodDescriptors();
      for(int j = 0; j < lmd.length; j++)
        System.out.println(
          "Method descriptor:\n  " +
          lmd[j].getMethod().toString());
      Method addListener = 
        events[i].getAddListenerMethod();
      System.out.println(
          "Add Listener Method:\n  " +
        addListener.toString());
      Method removeListener =
        events[i].getRemoveListenerMethod();
      System.out.println(
        "Remove Listener Method:\n  " +
        removeListener.toString());
      System.out.println("====================");
    }
  }
  // Dump the class of your choice:
  public static void main(String[] args) {
    if(args.length < 1) {
      System.err.println("usage: \n" +
        "BeanDumper fully.qualified.class");
      System.exit(0);
    }
    Class c = null;
    try {
      c = Class.forName(args[0]);
    } catch(ClassNotFoundException ex) {
      System.err.println(
        "Couldn't find " + args[0]);
      System.exit(0);
    }
    dump(c);
  }
} ///:~

class name: Frog
Property type:
  Color
Property name:
  color
Read method:
  public Color getColor()
Write method:
  public void setColor(Color)
====================
Property type:
  Spots
Property name:
  spots
Read method:
  public Spots getSpots()
Write method:
  public void setSpots(Spots)
====================
Property type:
  boolean
Property name:
  jumper
Read method:
  public boolean isJumper()
Write method:
  public void setJumper(boolean)
====================
Property type:
  int
Property name:
  jumps
Read method:
  public int getJumps()
Write method:
  public void setJumps(int)
====================
Public methods:
public void setJumps(int)
public void croak()
public void removeActionListener(ActionListener)
public void addActionListener(ActionListener)
public int getJumps()
public void setColor(Color)
public void setSpots(Spots)
public void setJumper(boolean)
public boolean isJumper()
public void addKeyListener(KeyListener)
public Color getColor()
public void removeKeyListener(KeyListener)
public Spots getSpots()
======================
Event support:
Listener type:
  KeyListener
Listener method:
  keyTyped
Listener method:
  keyPressed
Listener method:
  keyReleased
Method descriptor:
  public void keyTyped(KeyEvent)
Method descriptor:
  public void keyPressed(KeyEvent)
Method descriptor:
  public void keyReleased(KeyEvent)
Add Listener Method:
  public void addKeyListener(KeyListener)
Remove Listener Method:
  public void removeKeyListener(KeyListener)
====================
Listener type:
  ActionListener
Listener method:
  actionPerformed
Method descriptor:
  public void actionPerformed(ActionEvent)
Add Listener Method:
  public void addActionListener(ActionListener)
Remove Listener Method:
  public void removeActionListener(ActionListener)
====================