Adapter大概就是一个转换interface的class。就比如说现在我们有两个interface

public interface Student {
    public void studentIntroduction();
}

public interface People {
    public void peopleIntroduction();	 
}

一个是student，一个是people，然后随便建个人去implement student这个interface

public class Yidow implements Student {
    public void studentIntroduction(){
        System.out.println("I'm a student");
    }
}

这时候我们就要想啦，学生也是人啊，为啥Yidow不能是个人呢？所以我们建一个adapter

public class Adapter implements People { 
    Student newStudent; 
    public adapter(Student std){ 
        newStudent = std; 
    }  
    public void peopleIntroduction(){ 
        newStudent.studentIntroduction(); 
    } 
}

建完adapter以后我们就可以这样用

public class Main {	
	public static void main(String[] args) {
		Yidow yidow = new Yidow();
		People adapterYidow = new Adapter(yidow);
		yidow.studentIntroduction();
		adapterYidow.peopleIntroduction();
        }
}

Output:

I'm a student
I'm a student

所以其实output都是一样的，但是就是改变了一下interface