设计模式(13) --适配器模式(3种实现方式）

清疚 2023-06-15 07:12 21阅读 0赞

### 文章目录 ###

*  基本介绍
 *  适配器模式工作原理
 *  三种实现方式
 *   *  类适配器模式
     *   *  注意:
     *  对象适配器
     *   *  总结
     *  接口适配器
 *  适配器模式在SpringMVC 框架应用的源码剖析
 *  总结:

# 基本介绍 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70]

# 适配器模式工作原理 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 1]

# 三种实现方式 #

## 类适配器模式 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 2]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 3]

代码:  
![在这里插入图片描述][20191121101723763.png]  
Voltage220V

//被适配的类
    public class Voltage220V { 
    	//输出220V的电压
    	public int output220V() { 
    		int src = 220;
    		System.out.println("电压=" + src + "伏");
    		return src;
    	}
    }

IVoltage5V

//适配接口
    public interface IVoltage5V { 
    	public int output5V();
    }

VoltageAdapter

//适配器类
    public class VoltageAdapter extends Voltage220V implements IVoltage5V { 
    
    	@Override
    	public int output5V() { 
    		// TODO Auto-generated method stub
    		//获取到220V电压
    		int srcV = output220V();
    		int dstV = srcV / 44 ; //转成 5v
    		return dstV;
    	}
    }

测试:Client

public class Client { 
    	public static void main(String[] args) { 
    		// TODO Auto-generated method stub
    		System.out.println(" === 类适配器模式 ====");
    		Phone phone = new Phone();
    		phone.charging(new VoltageAdapter());
    	}
    }

![在这里插入图片描述][20191121102640574.png]

### 注意: ###

![在这里插入图片描述][20191121102726581.png]

## 对象适配器 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 4]  
![在这里插入图片描述][20191121102810807.png]  
类图  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 5]  
代码:  
![在这里插入图片描述][20191121103032601.png]  
其他类不变，改下适配器类VoltageAdapter:

//适配器类
    public class VoltageAdapter  implements IVoltage5V { 
    	private Voltage220V voltage220V; // 关联关系-聚合 
    	
    	//通过构造器，传入一个 Voltage220V 实例
    	public VoltageAdapter(Voltage220V voltage220v) { 		
    		this.voltage220V = voltage220v;
    	}
    
    	@Override
    	public int output5V() { 		
    		int dst = 0;
    		if(null != voltage220V) { 
    			int src = voltage220V.output220V();//获取220V 电压
    			System.out.println("使用对象适配器，进行适配~~");
    			dst = src / 44;
    			System.out.println("适配完成，输出的电压为=" + dst);
    		}		
    		return dst;		
    	}
    }

测试Client

public class Client { 
    
    	public static void main(String[] args) { 
    		// TODO Auto-generated method stub
    		System.out.println(" === 对象适配器模式 ====");
    		Phone phone = new Phone();
    		phone.charging(new VoltageAdapter(new Voltage220V()));
    	}
    
    }

![在这里插入图片描述][20191121103253908.png]

### 总结 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 6]

## 接口适配器 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 7]  
安卓上使用接口适配器的实例:  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 8]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 9]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 10]  
自己写个案例:  
![在这里插入图片描述][20191121104133101.png]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 11]  
Interface4

public interface Interface4 { 
    	public void m1();
    	public void m2();
    	public void m3();
    	public void m4();
    }

AbsAdapter

//在AbsAdapter 我们将 Interface4 的方法进行默认实现
    public abstract class AbsAdapter implements Interface4 { 
    
    	//默认实现
    	public void m1() { 
    
    	}
    
    	public void m2() { 
    
    	}
    
    	public void m3() { 
    
    	}
    
    	public void m4() { 
    
    	}
    }

测试Client

public class Client { 
    	public static void main(String[] args) { 
    		
    		AbsAdapter absAdapter = new AbsAdapter() { 
    			//只需要去覆盖我们 需要使用 接口方法
    			@Override
    			public void m1() { 
    				// TODO Auto-generated method stub
    				System.out.println("使用了m1的方法");
    			}
    		};
    		
    		absAdapter.m1();
    	}
    }

![在这里插入图片描述][20191121104327538.png]

# 适配器模式在SpringMVC 框架应用的源码剖析 #

![5)][5]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 12]  
**动手写 SpringMVC 通 过 适配器设计模式 获取到对应的 Controller 的源码**  
![在这里插入图片描述][20191121105056246.png]  
Controller

//多种Controller实现 
    public interface Controller { 
    
    }
    
    class HttpController implements Controller { 
    	public void doHttpHandler() { 
    		System.out.println("http...");
    	}
    }
    
    class SimpleController implements Controller { 
    	public void doSimplerHandler() { 
    		System.out.println("simple...");
    	}
    }
    
    class AnnotationController implements Controller { 
    	public void doAnnotationHandler() { 
    		System.out.println("annotation...");
    	}
    }

HandlerAdapter

///定义一个Adapter接口 
    public interface HandlerAdapter { 
    	public boolean supports(Object handler);
    
    	public void handle(Object handler);
    }
    
    // 多种适配器类
    
    class SimpleHandlerAdapter implements HandlerAdapter { 
    
    	public void handle(Object handler) { 
    		((SimpleController) handler).doSimplerHandler();
    	}
    
    	public boolean supports(Object handler) { 
    		return (handler instanceof SimpleController);
    	}
    
    }
    
    class HttpHandlerAdapter implements HandlerAdapter { 
    
    	public void handle(Object handler) { 
    		((HttpController) handler).doHttpHandler();
    	}
    
    	public boolean supports(Object handler) { 
    		return (handler instanceof HttpController);
    	}
    
    }
    
    class AnnotationHandlerAdapter implements HandlerAdapter { 
    
    	public void handle(Object handler) { 
    		((AnnotationController) handler).doAnnotationHandler();
    	}
    
    	public boolean supports(Object handler) { 
    
    		return (handler instanceof AnnotationController);
    	}
    
    }

DispatchServlet

import java.util.ArrayList;
    import java.util.List;
    public class DispatchServlet { 
    	public static List<HandlerAdapter> handlerAdapters = new ArrayList<HandlerAdapter>();
    
    	public DispatchServlet() { 
    		handlerAdapters.add(new AnnotationHandlerAdapter());
    		handlerAdapters.add(new HttpHandlerAdapter());
    		handlerAdapters.add(new SimpleHandlerAdapter());
    	}
    
    	public void doDispatch() { 
    
    		// 此处模拟SpringMVC从request取handler的对象，
    		// 适配器可以获取到希望的Controller
    		 HttpController controller = new HttpController();
    		// AnnotationController controller = new AnnotationController();
    		//SimpleController controller = new SimpleController();
    		// 得到对应适配器
    		HandlerAdapter adapter = getHandler(controller);
    		// 通过适配器执行对应的controller对应方法
    		adapter.handle(controller);
    	}
    	public HandlerAdapter getHandler(Controller controller) { 
    		//遍历：根据得到的controller(handler), 返回对应适配器
    		for (HandlerAdapter adapter : this.handlerAdapters) { 
    			if (adapter.supports(controller)) { 
    				return adapter;
    			}
    		}
    		return null;
    	}
    	public static void main(String[] args) { 
    		new DispatchServlet().doDispatch(); // http...
    	}
    }

![在这里插入图片描述][20191121105706102.png]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 13]  
个人感觉:这个写法太精妙了，因为各个controller方法名不同。①怎么让这些方法变成一个统一的? 于是想到用每个controller对应一个adapter实现类，这个adapter统一实现adapet接口。②如何判断传进来的controller用哪个adapt实现类?这句话白话说就是 根据controller找到对应的adapt，于是在dispatchservelt中先把所有的adapt实现来放在一个集合中，遍历，用每个adapt提供的support方法，找到自己。于是 就是可以使用这个对应的adapter干自己喜欢的事情了。！！

# 总结: #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 14]

--------------------

完

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20191121100402580.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20191121100436384.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20191121100633363.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20191121101556630.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[20191121101723763.png]: https://img-blog.csdnimg.cn/20191121101723763.png
[20191121102640574.png]: https://img-blog.csdnimg.cn/20191121102640574.png
[20191121102726581.png]: https://img-blog.csdnimg.cn/20191121102726581.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 4]: https://img-blog.csdnimg.cn/20191121102751473.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[20191121102810807.png]: https://img-blog.csdnimg.cn/20191121102810807.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 5]: https://img-blog.csdnimg.cn/20191121102958788.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[20191121103032601.png]: https://img-blog.csdnimg.cn/20191121103032601.png
[20191121103253908.png]: https://img-blog.csdnimg.cn/20191121103253908.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 6]: https://img-blog.csdnimg.cn/2019112110332426.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 7]: https://img-blog.csdnimg.cn/2019112110341957.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 8]: https://img-blog.csdnimg.cn/20191121103549347.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 9]: https://img-blog.csdnimg.cn/20191121103950593.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 10]: https://img-blog.csdnimg.cn/20191121104016896.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[20191121104133101.png]: https://img-blog.csdnimg.cn/20191121104133101.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 11]: https://img-blog.csdnimg.cn/20191121104540912.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[20191121104327538.png]: https://img-blog.csdnimg.cn/20191121104327538.png
[5]: https://img-blog.csdnimg.cn/20191121104807424.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 12]: https://img-blog.csdnimg.cn/20191121104858584.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[20191121105056246.png]: https://img-blog.csdnimg.cn/20191121105056246.png
[20191121105706102.png]: https://img-blog.csdnimg.cn/20191121105706102.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 13]: https://img-blog.csdnimg.cn/20191121105726896.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1_size_16_color_FFFFFF_t_70 14]: https://img-blog.csdnimg.cn/20191121105821388.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JhaWR1XzIxMzQ5NjM1,size_16,color_FFFFFF,t_70