Adapter适配器模式

Adapter pattern

In software engineering, the adapter pattern is a software design pattern (also known as wrapper, an alternative naming shared with the decorator pattern) that allows the interface of an existing class to be used as another interface.[1] It is often used to make existing classes work with others without modifying their source code.
An example is an adapter that converts the interface of a Document Object Model of an XML document into a tree structure that can be displayed.

Structure

Example

public class Main {
    public static void main(String[] args) throws Exception {
        FileInputStream fis = new FileInputStream("c:/test.text");
				//Adapter
        InputStreamReader isr = new InputStreamReader(fis);
        //public BufferedReader(Reader in) 
        //BufferedReader 的参数为Reader
        //InputstreamReader 将 FileInputStream fis 转为 Reader
        BufferedReader br = new BufferedReader(isr);
        String line = br.readLine();
        while (line != null && !line.equals("")) {
            System.out.println(line);
        }
        br.close();
    }
}

Summary

• 类似于转接头的中转作用
• 常见的Adapter类反而不是Adapter
  • WindowAdapter
  • KeyAdapter