package designpatterns.strategy;
import java.util.*;
import java.io.*;

/**//**
* 该类是策略模式中的Context类，用来管理算法运行的上下文环境
* @author Feifan Yin
*
*/
public class Context ...{
private Strategy m_strategy;
private byte[] inData;
private byte[] outData;
public Context(Strategy pStrategy, File file)...{
m_strategy = pStrategy;
try...{
FileInputStream fi = new FileInputStream(file);
}catch(Exception e)...{
e.printStackTrace();
}
}

public void contextInterface()...{
if(inData != null)...{
this.outData = m_strategy.algorithmInterface(inData);
}
}

void printResult()...{
if(this.outData != null)...{
System.out.println(new String(outData));
}
}

public static final void main(String arg[])...{
//选择一个算法 
Strategy strategy = new ConcreateStrategyA();
//Strategy strategy = new ConcreateStrategyB();
//Strategy strategy = new ConcreateStrategyC();
//给出上下文环境 
Context context = new Context(strategy,new File("in.txt"));
//利用上下文环境驱动算法执行 
context.contextInterface();
//输出算法执行结果 
context.printResult();
}
}

package designpatterns.strategy;

/**//**
* 表示一个抽象的算法，为具体的算法定义皆空
* @author Feifan Yin
*
*/
public abstract class Strategy ...{
/**//**
* 抽象的算法接口
* @param data 输入数据
* @return 输出数据
*/
public abstract byte[] algorithmInterface(byte[] data);
}

package designpatterns.strategy;

/**//**
* 算法封装类，表示一个具体的算法
* @author Feifan Yin
*
*/
public class ConcreateStrategyA extends Strategy...{
/**//**
* 具体算法的实现
*/
public byte[] algorithmInterface(byte[] data) ...{
// TODO Auto-generated method stub 
for(int i = 0;i<data.length; ++i)...{
data[i] = (byte) ~data[i];
}
return data;
}
}

package designpatterns.strategy;

/**//**
* 算法封装类，表示一个具体的算法
* @author Feifan Yin
*
*/
public class ConcreateStrategyB extends Strategy...{
/**//**
* 具体算法的实现
*/
public byte[] algorithmInterface(byte[] data) ...{
// TODO Auto-generated method stub 
for(int i = 0;i<data.length; ++i)...{
data[i] = (byte) (6 ^ data[i]);
}
return data;
}
}

package designpatterns.strategy;

/**//**
* 算法封装类，表示一个具体的算法
* @author Feifan Yin
*
*/
public class ConcreateStrategyC extends Strategy...{
/**//**
* 具体算法的实现
*/
public byte[] algorithmInterface(byte[] data) ...{
// TODO Auto-generated method stub 
for(int i = 0;i<data.length; ++i)...{
data[i] = (byte) (123 & data[i]);
}
return data;
}
}