适配器模式

public class Source {
	public void method1() {
		System.out.println("this is original method!");
	}
}

public interface Targetable {
	/* 与原类中的方法相同 */
	public void method1();
	/* 新类的方法 */
	public void method2();
}

public class Adapter extends Source implements Targetable {
	@Override
	public void method2() {
		System.out.println("this is the targetable method!");
	}
}

Adapter类继承Source类，实现Targetable接口，下面是测试类：

public class AdapterTest {

	public static void main(String[] args) {
		Targetable target = new Adapter();
		target.method1();
		target.method2();
	}
}

输出：

this is original method!
this is the targetable method!

这样Targetable接口的实现类就具有了Source类的功能。

对象的适配器模式

public class Wrapper implements Targetable {
	private Source source;	
	public Wrapper(Source source){
		super();
		this.source = source;
	}
	@Override
	public void method2() {
		System.out.println("this is the targetable method!");
	}
	@Override
	public void method1() {
		source.method1();
	}
}