Java反射

反射的使用方法

userSeriver接口

public interface UserService {

   void add();

   int delete(String id);

   int update(String id, String name, String age);

   int insert(String id, String name, String age);
}
UserServiceImpl 实现类

public class UserServiceImpl implements UserService {

   @Override
   public void add() {
       System.out.println("add个啥，你啥也没传");
   }

   @Override
   public int delete(String id) {
       System.out.println("id:"+id+"被删除了");
       return 0;
   }

   @Override
   public int update(String id, String name, String age) {
       System.out.println("id:"+id+"修改成功[name:"+name+"age:"+age+"]");
       return 1;
   }

   @Override
   public int insert(String id, String name, String age) {
       System.out.println("插入成功[id:"+id+"name:"+name+"age:"+age+"]");
       return 2;
   }

}
MainTest测试类

public class MainTest {

   public static void main(String[] args) {
       try {
           Class<?> clazz1 = Class.forName("com.test.UserServiceImpl");

           Method method1 = clazz1.getMethod("update", String.class, String.class, String.class);
           Object invoke1 = method1.invoke(clazz1.newInstance(), "id100","王大拿","51");
           System.out.println(invoke1);

           Class<?> clazz2 = UserServiceImpl.class;
           for (Method method : clazz2.getMethods()) {
               if (method.getName().equals("insert")) {
                   Method thisMethod = clazz2.getMethod(method.getName(), method.getParameterTypes());
                   Object obj = thisMethod.invoke(clazz2.newInstance(), "1", "张大炮", "28");
                   System.out.println(obj);
               }
           }

           UserService user = new UserServiceImpl();
           Class<?> clazz3 = user.getClass();
           Method method3 = clazz3.getMethod("add");
           Object invoke3 = method3.invoke(clazz3.newInstance());
           System.out.println(invoke3);

       } catch (Exception e) {
           e.printStackTrace(http://www.my516.com);
       }
   }
}

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