自定义一个测试注解

自定义@Test注解

1.创建Annotation类型文件，命名Test

@Retention(RetentionPolicy.RUNTIME)
public @interface Test {
     
	public String value();
}

2.自定义类，如类A，方法前添加注解

public class A {
     
	@Test("do")
	public void f1(){
     
		System.out.println("f1()");
	}
	public void f2(){
     
		System.out.println("f2()");
	}
	@Test("info")
	public void f3(String info,int age){
     
		System.out.println(info+":"+age);
	}
	@Test("hello")
	public String f4(){
     
		return "hello";
	}
}

3，编写测试类AnnotationTest

public class AnnotationTest {
     
	public static void main(String[] args) {
     
		Scanner scanner = new Scanner(System.in);
		String name=scanner.next();
		try {
     
			Class<?> c = Class.forName(name);
			Object obj = c.newInstance();
			Method[] methods = c.getDeclaredMethods();
			for(Method mt:methods){
     
				Test test = mt.getDeclaredAnnotation(Test.class);
				String value=null;
				if(test!=null){
     
					Class<?>[] types = mt.getParameterTypes();
					value = test.value();
					Object result;
					if(types.length==0){
     
						result = mt.invoke(obj);
						System.out.println(result);
					}else{
     
						Object[] params=new Object[types.length];
						for (int i = 0; i < params.length; i++) {
     
							if(types[i]==String.class){
     
								params[i]="张三";
							}else if(types[i]==int.class){
     
								params[i]=18;
							}
						}
						result=mt.invoke(obj, params);
						System.out.println(result);
					}
				}
				System.out.println(test+":"+value);
			}
		} catch (Exception e) {
     
			e.printStackTrace();
		}
	}
}