设计模式之策略模式

main
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package com.strategy.com;

public class TestStrategy {

	/**
	 * @param args

    封装类：也叫上下文，对策略进行二次封装，目的是避免高层模块对策略的直接调用。
    抽象策略：通常情况下为一个接口，当各个实现类中存在着重复的逻辑时，则使用抽象类来封装这部分公共的代码，此时，策略模式看上去更像是模版方法模式。
    具体策略：具体策略角色通常由一组封装了算法的类来担任，这些类之间可以根据需要自由替换。
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		StrategyI strategy1 = new ConcreteStrategy1();
		StrategyI strategy2 = new ConcreteStrategy2();
		Context context = null;
		System.out.println("执行策略一");
		context = new Context(strategy1);
		context.excute();
		System.out.println("执行策略二");
		context = new Context(strategy2);
		context.excute();
	}

}
策略抽象类
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package com.strategy.com;

public interface StrategyI {
void doSomething();
}
策略具体类1
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package com.strategy.com;

public class ConcreteStrategy1 implements StrategyI {

	@Override
	public void doSomething() {
		// TODO Auto-generated method stub
		System.out.println("这是策略一");
	}

}
策略具体类2
==============================================================================
package com.strategy.com;

public class ConcreteStrategy2 implements StrategyI {

	@Override
	public void doSomething() {
		// TODO Auto-generated method stub
		System.out.println("这是策略二");
	}

}

封装类
===============================================================================
package com.strategy.com;

public class Context {
	private StrategyI strategy;

	public Context(StrategyI strategy) {
		this.strategy = strategy;
	}

	public void excute() {
		strategy.doSomething();
	}
}