状态模式-马士兵设计模式教程

//表示状态的接口类
public interface State {
void smile();
void cry();
void say();
}

//高兴的状态
public class HappyState implements State{
@Override
public void cry() {
System.out.println("高兴的哭");
}
@Override
public void say() {
System.out.println("高兴的说");
}
@Override
public void smile() {
System.out.println("高兴的笑");
}
}

//不高兴的状态
public class UnHappyState implements State{
@Override
public void cry() {
System.out.println("伤心的哭");
}
@Override
public void say() {
System.out.println("不高兴的说");
}
@Override
public void smile() {
System.out.println("不高兴的笑");
}
}

public class MM{
private State state = new HappyState();//在这里的状态决定了mm的行为
private String name;
public MM(State state){//可以在外部传递mm的状态
this.state=state;
}
public MM(){}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public void cry() {
state.cry();
}
public void say() {
state.say();
}
public void smile() {
state.smile();
}
}

public class Test {
public static void main(String[] args) {
MM mm = new MM(new HappyState());
mm.cry();
MM mm1=new MM(new UnHappyState());
mm1.cry();
/**
* 运行结果:
* 高兴的哭
* 伤心的哭
*/
}
}