一个Servlet处理N个请求可以用反射 (二)

柔光的暖阳◎ 2023-10-17 17:38 25阅读 0赞

一、web.xml配置文件

<servlet-mapping>
        <servlet-name>UserServlet</servlet-name>
        <url-pattern>*.do</url-pattern>
      </servlet-mapping>

二、JSP页面

<a href="find.do"> Find</a>
    	<p />
    	<a href="add.do"> Add</a>
    	<p />
       <a href="delete.do"> Delete</a>

三、Servlet页面

public void doGet(HttpServletRequest request, HttpServletResponse response)
    			throws ServletException, IOException {
    
    		response.setContentType("text/html;charset=utf-8");
    		PrintWriter out = response.getWriter();
    
    		// 获得提交的路径 :/find.do
    		String path = request.getServletPath();
    
    		// 截取出query
    		String methodName = path.substring(1, path.indexOf("."));
    
    		// out.println(methodName);
    
    		try {
    			// 利用反射
    			Method method = getClass().getDeclaredMethod(methodName,
    					HttpServletRequest.class, HttpServletResponse.class);
    			// 执行相应的方法
    			method.invoke(this, request, response);
    
    		} catch (Exception e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    
    		out.flush();
    		out.close();
    	}
    
    	private void add(HttpServletRequest request, HttpServletResponse response)
    			throws ServletException, IOException {
    
    		System.out.println("add action!");
    
    	}
    
    	private void delete(HttpServletRequest request, HttpServletResponse response)
    			throws ServletException, IOException {
    
    		System.out.println("del  action!");
    
    	}
    
    	private void find(HttpServletRequest request, HttpServletResponse response)
    			throws ServletException, IOException {
    
    		System.out.println("find  action!");
    
    	}
    
    	/**
    	 * The doPost method of the servlet. <br>
    	 * 
    	 * This method is called when a form has its tag value method equals to
    	 * post.
    	 * 
    	 * @param request
    	 *            the request send by the client to the server
    	 * @param response
    	 *            the response send by the server to the client
    	 * @throws ServletException
    	 *             if an error occurred
    	 * @throws IOException
    	 *             if an error occurred
    	 */
    	public void doPost(HttpServletRequest request, HttpServletResponse response)
    			throws ServletException, IOException {
    
    		doGet(request, response);
    	}

效果图: ![Center][]

[Center]: https://img-blog.csdn.net/20180104135329357?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvaGx4MjAwODA4MDg=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center