Question

我已经尝试了一切来使这个servlet正常工作，并且在下载了几个较旧的JRE和几个旧版本的Apache tomcat之后，它仍然无法正常工作。现在我正在使用Kepler for Java EE和JRE v1.7以及Tomcat v7。下面是我的java源代码和html - 我怀疑问题出在doGet方法本身，因为我认为我的文件路径命名正确，但我仍然返回一个空白页面。虽然问题可能在于形式动作 - 我对eclipse完全不熟悉。

<!DOCTYPE html> 
   <html>
       <head> <meta charset="ISO-8859-1">
          <title>Insert title here</title> 
       </head> 
     <body> 
        <form  action="/HelloWorld/HelloServlet" method="get">
            <input type="submit"  value="go to hello servlet"/>
        </form> 
     </body> 
   </html>`

HelloServaled.java

package com.tutorials.servlets;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class HelloServlet
 */
@WebServlet("/HelloServlet")
public class HelloServlet extends HttpServlet {


    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public HelloServlet() {
        super();
        // TODO Auto-generated constructor stub
    }
  /* @see Servlet#destroy()
     */
    public void destroy() {
        // TODO Auto-generated method stub
    }

    /**
     * @see HttpServlet#service(HttpServletRequest request,                                                                                                           >        HttpServletResponse response)
     */
    protected void service(HttpServletRequest request, HttpServletResponse  >      response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request,                           >        HttpServletResponse response)
     */

    protected void doGet(HttpServletRequest request, HttpServletResponse           >             response) throws ServletException, IOException {


             PrintWriter out = response.getWriter();
             out.println("I am in go get mehtod" );

        // TODO Auto-generated method stub
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request,                                            >       HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse               >       response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

    /**
     * @see HttpServlet#doPut(HttpServletRequest, HttpServletResponse)
     */
    protected void doPut(HttpServletRequest request, HttpServletResponse                    >       response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

}

Answer 1

您的主要问题在于您的表单action属性与您的servlet映射不同。

您的注释：（@WebServlet("/HelloServlet")）告诉应用服务器监听对＆＃34; / HelloServlet＆＃34;的请求，例如：http://eample.com/HelloServlet它是什么。

另一方面，您的表单将其操作设置为/HelloWorld/HelloServlet，这意味着帖子请求转到http://example.com/HelloWorld/HelloServlet

因此，当您的浏览器在那里发布时，应用程序会处理它应该如何处理它，因为您的servlet没有在那里听任何东西。

单击提交按钮时，在hello world java servlet中返回空白页面

1 个答案: