1.中介者模式

package com.jmj.pattern.mediator;

public abstract class Mediator {
    public abstract void constact(String message,Person person);
}

package com.jmj.pattern.mediator;

public class MediatorStructure extends Mediator{


    private HouseOwner houseOwner;
    private Tenant tenant;

    public HouseOwner getHouseOwner() {
        return houseOwner;
    }

    public void setHouseOwner(HouseOwner houseOwner) {
        this.houseOwner = houseOwner;
    }

    public Tenant getTenant() {
        return tenant;
    }

    public void setTenant(Tenant tenant) {
        this.tenant = tenant;
    }

    @Override
    public void constact(String message, Person person) {
            if (person==houseOwner){
                tenant.getMessage(message);
            }else{
                houseOwner.getMessage(message);
            }

    }

}

package com.jmj.pattern.mediator;

public class Person {
    protected String name;
    protected Mediator mediator;

    public Person(String name, Mediator mediator) {
        this.name = name;
        this.mediator = mediator;
    }
}

package com.jmj.pattern.mediator;

public class HouseOwner extends Person{
    public HouseOwner(String name, Mediator mediator) {
        super(name, mediator);
    }
    public void constact(String message){
        mediator.constact(message,this);
    }
    public void getMessage(String message){
        System.out.println("房主"+name+"获取到的信息是: "+message);
    }
}

package com.jmj.pattern.mediator;

public class Tenant extends Person{

    public Tenant(String name, Mediator mediator) {
        super(name, mediator);
    }
    //和中介联系
    public void constact(String message){
        mediator.constact(message,this);
    }
    public void getMessage(String message){
        System.out.println("租房者"+name+"获取到的信息是: "+message);
    }
}

package com.jmj.pattern.mediator;

public class Client {
    public static void main(String[] args) {
        MediatorStructure mediatorStructure = new MediatorStructure();
        Tenant tenant = new Tenant("李四", mediatorStructure);
        HouseOwner houseOwner = new HouseOwner("张三", mediatorStructure);

        mediatorStructure.setTenant(tenant);
        mediatorStructure.setHouseOwner(houseOwner);

        tenant.constact("我要租三室的房子");
                houseOwner.constact("我这里有三室的房子，你要租吗？");
    }
}

2.迭代器模式

 

3.访问者模式 

4.备忘录模式

5.解释器模式

触碰到编译原理，和二叉树先序遍历

package com.jmj.pattern.interpreter;

public abstract class AbstractExpression {
    public abstract int interpret(Context context);
}

package com.jmj.pattern.interpreter;

import java.util.HashMap;
import java.util.Map;

public class Context {
    private Map<Variable, Integer> map = new HashMap<>();

    public void assign(Variable var, Integer value) {
        map.put(var, value);
    }

    public int getValue(Variable variable) {
        return map.get(variable);
    }
}

package com.jmj.pattern.interpreter;

/**
 * 加法表达式类
 */
public class Minus extends AbstractExpression{

    private AbstractExpression left;
    private AbstractExpression right;

    public Minus(AbstractExpression left, AbstractExpression right) {
        this.left = left;
        this.right = right;
    }

    @Override
    public int interpret(Context context) {
        //将左边表达式的结果和右边表达式的结果进行相加

        return left.interpret(context)-right.interpret(context);
    }

    @Override
    public String toString() {
        return "("+left+"-"+right+")";
    }
}

package com.jmj.pattern.interpreter;

/**
 * 加法表达式类
 */
public class Plus extends AbstractExpression{

    private AbstractExpression left;
    private AbstractExpression right;

    public Plus(AbstractExpression left, AbstractExpression right) {
        this.left = left;
        this.right = right;
    }

    @Override
    public int interpret(Context context) {
        //将左边表达式的结果和右边表达式的结果进行相加

        return left.interpret(context)+right.interpret(context);
    }

    @Override
    public String toString() {
        return "("+left+"+"+right+")";
    }
}

package com.jmj.pattern.interpreter;

public class Variable extends AbstractExpression{

    //声明存储变量名的成员变量
    private String name;

    public Variable(String name) {
        this.name = name;
    }

    @Override
    public int interpret(Context context) {
        //直接返回变量的值
        return context.getValue(this);
    }


    @Override
    public String toString() {
        return name ;
    }
}

package com.jmj.pattern.interpreter;

public class Client {
    public static void main(String[] args) {
        //创建环境对象
        Context context = new Context();

        Variable a = new Variable("a");
        Variable b = new Variable("b");
        Variable c = new Variable("c");
        Variable d = new Variable("d");

        //
        context.assign(a,1);
        context.assign(b,2);
        context.assign(c,3);
        context.assign(d,4);

        AbstractExpression expression=new Minus(a,new Plus(new Minus(b,c),d));

        int interpret = expression.interpret(context);
        System.out.println(expression+"="+interpret);
    }
}