beandumper.java

Thinking in JAVA第四版源代码

//: gui/BeanDumper.java
// Introspecting a Bean.
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import java.lang.reflect.*;
import static net.mindview.util.SwingConsole.*;

public class BeanDumper extends JFrame {
  private JTextField query = new JTextField(20);
  private JTextArea results = new JTextArea();
  public void print(String s) { results.append(s + "\n"); }
  public void dump(Class<?> bean) {
    results.setText("");
    BeanInfo bi = null;
    try {
      bi = Introspector.getBeanInfo(bean, Object.class);
    } catch(IntrospectionException e) {
      print("Couldn't introspect " +  bean.getName());
      return;
    }
    for(PropertyDescriptor d: bi.getPropertyDescriptors()){
      Class<?> p = d.getPropertyType();
      if(p == null) continue;
      print("Property type:\n  " + p.getName() +
        "Property name:\n  " + d.getName());
      Method readMethod = d.getReadMethod();
      if(readMethod != null)
        print("Read method:\n  " + readMethod);
      Method writeMethod = d.getWriteMethod();
      if(writeMethod != null)
        print("Write method:\n  " + writeMethod);
      print("====================");
    }
    print("Public methods:");
    for(MethodDescriptor m : bi.getMethodDescriptors())
      print(m.getMethod().toString());
    print("======================");
    print("Event support:");
    for(EventSetDescriptor e: bi.getEventSetDescriptors()){
      print("Listener type:\n  " +
        e.getListenerType().getName());
      for(Method lm : e.getListenerMethods())
        print("Listener method:\n  " + lm.getName());
      for(MethodDescriptor lmd :
          e.getListenerMethodDescriptors() )
        print("Method descriptor:\n  " + lmd.getMethod());
      Method addListener= e.getAddListenerMethod();
      print("Add Listener Method:\n  " + addListener);
      Method removeListener = e.getRemoveListenerMethod();
      print("Remove Listener Method:\n  "+ removeListener);
      print("====================");
    }
  }
  class Dumper implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      String name = query.getText();
      Class<?> c = null;
      try {
        c = Class.forName(name);
      } catch(ClassNotFoundException ex) {
        results.setText("Couldn't find " + name);
        return;
      }
      dump(c);
    }
  }
  public BeanDumper() {
    JPanel p = new JPanel();
    p.setLayout(new FlowLayout());
    p.add(new JLabel("Qualified bean name:"));
    p.add(query);
    add(BorderLayout.NORTH, p);
    add(new JScrollPane(results));
    Dumper dmpr = new Dumper();
    query.addActionListener(dmpr);
    query.setText("frogbean.Frog");
    // Force evaluation
    dmpr.actionPerformed(new ActionEvent(dmpr, 0, ""));
  }
  public static void main(String[] args) {
    run(new BeanDumper(), 600, 500);
  }
} ///:~