java暴力反射

柔情只为你懂 2023-05-29 13:25 32阅读 0赞

暴力反射可以获取java类中私有的方法

# 儿子 #

package cn.itcast.travel.web.servlet;
    
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    
    @WebServlet("/user/*")
    public class UserServlet extends BaseServlet { 
        protected void add(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
            System.out.println("userServlet add方法");
    
        }
    
        protected void find(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
            System.out.println("userServlet find方法");
        }
    }

# 老爹 #

package cn.itcast.travel.web.servlet;
    
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    import java.lang.reflect.InvocationTargetException;
    import java.lang.reflect.Method;
    
    public class BaseServlet extends HttpServlet { 
        @Override
        protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 
    // 完成方法分发
    // 获取请求路径
                String uri =  req.getRequestURI();// /travel/user/123
    
    // 获取方法名称
          String methodname =  uri.substring(uri.lastIndexOf("/")+1);
            System.out.println(methodname);
    // 获取方法对象 反射相关的知识
            try { 
    // getDeclaredMethod忽略访问权限修饰符
                Method method = this.getClass().getDeclaredMethod(methodname,HttpServletRequest.class,HttpServletResponse.class);
            //执行方发
    // 暴力反射
                method.setAccessible(true);
                method.invoke(this,req,resp);
            } catch (NoSuchMethodException e) { 
                e.printStackTrace();
            } catch (IllegalAccessException e) { 
                e.printStackTrace();
            } catch (InvocationTargetException e) { 
                e.printStackTrace();
            }
        }
    }