java内部类概念（Java内部类与相关的设计模式(一)）

abstract class Contents {

abstract public int value();

}

interface Destination {

String readLabel();

}

public class Parcel3 {

private class PContents extends Contents {

private int i = 11;

public int value() { return i; }

}

protected class PDestination implements Destination {

private String label;

private PDestination(String whereTo) {

label = whereTo;

}

public String readLabel() { return label; }

}

public Destination dest(String s) {

return new PDestination(s);

}

public Contents cont() {

return new PContents();

}

}

class Test {

public static void main(String[] args) {

Parcel3 p = new Parcel3();

Contents c = p.cont();

Destination d = p.dest(            ”Tanzania
  
 
  
 
  
 
  
 
  
 
  
 ”);

// Illegal — cant access private class:

//Parcel3.PContents a = p.new PContents();这是另一种在外部类得到内部类对象的语法

}

} ///:~

outerClass.innerClass innerObject=outerObject.new InnerClass(Constructor Parameters);

public class Parcel3 {

private valueRate=2;

private class PContent implements Contents {

private int i = 11*valueRate;

public int value() { return i; }

}

protected class PDestination implements Destination {

　 private String label;

　 private PDestination(String whereTo) {label = whereTo;}

　 public String readLabel() { return label; }

　}

public Destination dest(String s) {

return new PDestination(s);

}

public Contents cont() {

　 return new PContent();

}

}