第28章 行为型模式大PK

//行为型模式大PK——策略模式和命令模式
//实例：用策略模式实现压缩算法
#include <iostream>
#include <string>

using namespace std;

//抽象压缩算法
class Algorithm
{
public:
    //压缩算法
    virtual bool compress(string source, string to) = 0;
    //解压算法
    virtual bool uncompress(string source, string to) = 0;

    virtual ~Algorithm(){}
};

//具体算法:zip算法
class Zip : public Algorithm
{
public:
    //zip格式的压缩算法
    bool compress(string source, string to)
    {
        cout << source << " --> " << to <<" ZIP压缩成功" <<endl;
        return true;
    }
    //zip格式的解压缩算法
    bool uncompress(string source, string to)
    {
        cout << source <<" --> " << to <<" ZIP解压缩成功" <<endl;
        return true;
    }
};

//具体算法:Gzip
class Gzip : public Algorithm
{
public:
    //gzip格式的压缩算法
    bool compress(string source, string to)
    {
        cout << source << " --> " << to <<" GZIP压缩成功" <<endl;
        return true;
    }
    //gzip格式的解压缩算法
    bool uncompress(string source, string to)
    {
        cout << source <<" --> " << to <<" GZIP解压缩成功" <<endl;
        return true;
    }
};

//环境角色
class Context
{
private:
    Algorithm* al; //指向抽象算法
public:
    Context(Algorithm* al)
    {
        this->al = al;
    }

    //设置算法策略
    void setAlgorithm(Algorithm* al)
    {
        this->al = al;
    }

    //执行压缩算法
    bool compress(string source, string to)
    {
        return al->compress(source ,to);
    }

    //执行解压缩算法
    bool uncompress(string source, string to)
    {
        return al->uncompress(source ,to);
    }
};

int main()
{
    //创建两种算法策略
    Algorithm* alZip = new Zip();
    Algorithm* alGzip = new Gzip();

    //创建环境角色，并执行zip算法
    Context ctx(alZip);

    cout <<"========执算zip算法========" << endl;
    //执行压缩算法
    ctx.compress("c:\\window", "d:\\windows.zip");
    //执行解压缩算法
    ctx.compress("c:\\window.zip", "d:\\windows");

    //"========执算gzip算法========"
    cout <<"========执算gzip算法========" << endl;
    //更换算法
    ctx.setAlgorithm(alGzip);

    //执行压缩算法
    ctx.compress("c:\\window", "d:\\windows.zip");
    //执行解压缩算法
    ctx.compress("c:\\window.zip", "d:\\windows");

    delete alZip;
    delete alGzip;
    return 0;
};
/*输出结果：
========执算zip算法========
c:\window --> d:\windows.zip ZIP压缩成功
c:\window.zip --> d:\windows ZIP压缩成功
========执算gzip算法========
c:\window --> d:\windows.zip GZIP压缩成功
c:\window.zip --> d:\windows GZIP压缩成功
*/

//行为型模式大PK——策略模式和命令模式
//实例：用命令模式实现压缩算法
#include <iostream>
#include <string>

using namespace std;

//抽象接收者
class IReceiver
{
public:
    //压缩
    virtual bool compress(string source, string to) = 0;
    //解压
    virtual bool uncompress(string source, string to) = 0;

    virtual ~IReceiver(){}
};

//zip接收者
class ZipReceiver : public IReceiver
{
public:
    //压缩
    bool compress(string source, string to)
    {
        cout << source << " --> " << to <<" ZIP压缩成功" <<endl;
        return true;
    }
    //解压
    bool uncompress(string source, string to)
    {
        cout << source << " --> " << to <<" ZIP解压缩成功" <<endl;
        return true;
    }
};

//Gzip接收者
class GzipReceiver : public IReceiver
{
public:
    //压缩
    bool compress(string source, string to)
    {
        cout << source << " --> " << to <<" GZIP压缩成功" <<endl;
        return true;
    }
    //解压
    bool uncompress(string source, string to)
    {
        cout << source << " --> " << to <<" GZIP解压缩成功" <<endl;
        return true;
    }
};

//抽象压缩命令
class AbstractCmd
{
protected:
    //持有接收者的引用
    IReceiver* zip;
    IReceiver* gzip;
public:
    AbstractCmd()
    {
        zip = new ZipReceiver();
        gzip = new GzipReceiver();
    }
    virtual ~AbstractCmd()
    {
        delete zip;
        delete gzip;
    }

    //抽象方法，命令的具体单元
    virtual bool execute(string source, string to) = 0;
};

//zip压缩命令
class ZipCompressCmd : public AbstractCmd
{
public:
    bool execute(string source, string to)
    {
        return  zip->compress(source, to);
    }
};

//zip解压缩命令
class ZipUncompressCmd : public AbstractCmd
{
public:
    bool execute(string source, string to)
    {
       return  zip->uncompress(source, to);
    }
};

//gzip压缩命令
class GzipCompressCmd : public AbstractCmd
{
public:
    bool execute(string source, string to)
    {
       return  gzip->compress(source, to);
    }
};

//gzip解压缩命令
class GzipUncompressCmd : public AbstractCmd
{
public:
    bool execute(string source, string to)
    {
       return  gzip->uncompress(source, to);
    }
};

//调用者
class Invoker
{
private:
    //持有抽象命令的引用
    AbstractCmd* cmd;
public:
    Invoker(AbstractCmd* cmd)
    {
        this->cmd = cmd;
    }

    //执行命令
    bool execute(string source, string to)
    {
        return cmd->execute(source, to);
    }

    void setCommand(AbstractCmd* cmd)
    {
        this->cmd = cmd;
    }
};

int main()
{
    //定义一个命令，压缩一个文件
    AbstractCmd* cmd = new ZipCompressCmd();
    //AbstractCmd* cmd = new ZipUncompressCmd();//换命令

    //定义调用者
    Invoker* invoker = new Invoker(cmd);
    //执行压缩命令
    cout <<"========执行压缩命令========"<<endl;

    invoker->execute("c:\\windows", "d:\\windows.zip");

    return 0;
};
/*输出结果：
========执行压缩命令========
c:\windows --> d:\windows.zip ZIP压缩成功
*/