什么是Bean[Java编程]

//: Frog.java
// A trivial Java Bean
package frogbean;
import java.awt.*;
import java.awt.event.*;

class Spots {}

public class Frog {
  private int jumps;
  private Color color;
  private Spots spots;
  private boolean jmpr;
  public int getJumps() { return jumps; }
  public void setJumps(int newJumps) { 
    jumps = newJumps;
  }
  public Color getColor() { return color; }
  public void setColor(Color newColor) { 
    color = newColor; 
  }
  public Spots getSpots() { return spots; }
  public void setSpots(Spots newSpots) {
    spots = newSpots; 
  }
  public boolean isJumper() { return jmpr; }
  public void setJumper(boolean j) { jmpr = j; }
  public void addActionListener(
      ActionListener l) {
    //...
  }
  public void removeActionListener(
      ActionListener l) {
    // ...
  }
  public void addKeyListener(KeyListener l) {
    // ...
  }
  public void removeKeyListener(KeyListener l) {
    // ...
  }
  // An "ordinary" public method:
  public void croak() {
    System.out.println("Ribbet!");
  }
} ///:~