设计模式——策略模式

/*
 * Copyright (c) 2017. Xiaomi.Co.Ltd All rights reserved
 */

package com.pt.strategy;

import java.util.List;

/**
 * @description 职责的抽象
 * @author panteng
 * @date 17-2-27.
 */
public interface ISorting {
    void sort(List<Integer> list);
}

/*
 * Copyright (c) 2017. Xiaomi.Co.Ltd All rights reserved
 */

package com.pt.strategy;

import java.util.Collections;
import java.util.List;

/**
 * @description 职责实现策略的实体类
 * @author panteng
 * @date 17-2-27.
 */
public class SortStrategy1 implements ISorting {
    public void sort(List<Integer> list){
        System.out.println("===========方式1排序==========");
        Collections.sort(list);
    }
}

/*
 * Copyright (c) 2017. Xiaomi.Co.Ltd All rights reserved
 */

package com.pt.strategy;

import java.util.List;

/**
 * @description 职责实现策略的实体类
 * @author panteng
 * @date 17-2-27.
 */
public class SortStrategy2 implements ISorting {
    //插入排序
    public void sort(List<Integer> list){
        System.out.println("===========方式2排序==========");
        int i = 1;
        for (i = 1; i < list.size(); i++) {
            int key = list.get(i);
            int j = i;
            while (j > 0 && key < list.get(j - 1)) {
                list.set(j, list.get(j - 1));
                j--;
            }
            list.set(j, key);
        }
    }
}

/*
 * Copyright (c) 2017. Xiaomi.Co.Ltd All rights reserved
 */

package com.pt.strategy;

import java.util.List;

/**
 * @description 策略的上下文环境，之所以由此上下文环境是为了便于做一些共性处理，比如对参数的校验,执行时间统计等；假如没有此上下文，需要在每一个策略类里面校验
 * @author panteng
 * @date 17-2-27.
 */
public class SortContext {
    ISorting sorting;
    public SortContext(){
    }
    public SortContext(ISorting sorting){
        this.sorting = sorting;
    }
    public ISorting getSorting(){
        return sorting;
    }
    public void setSorting(ISorting sorting){
        this.sorting = sorting;
    }

    public void Sort(List<Integer> list){
        sorting.sort(list);
    }
}

/*
 * Copyright (c) 2017. Xiaomi.Co.Ltd All rights reserved
 */

package com.pt.strategy;

import org.junit.Test;

import java.util.ArrayList;
import java.util.List;

/**
 * @description
 * @author panteng
 * @date 17-2-27.
 */
public class StrategyTest {
    @Test
    public void strategyTest(){
        List<Integer> list = new ArrayList<Integer>();
        list.add(3);
        list.add(23);
        list.add(4);
        list.add(14);
        list.add(2);
        list.add(8);
        list.add(21);
        list.add(56);
        list.add(14);

        ISorting strategy1 = new SortStrategy1();
        ISorting strategy2 = new SortStrategy2();

        SortContext sortContext = new SortContext(strategy1);
        sortContext.Sort(list);
        System.out.println(list);

        /*SortContext sortContext = new SortContext();
        sortContext.setSorting(strategy2);
        sortContext.Sort(list);
        System.out.println(list);*/

    }
}