Question

这是我的Java类，我通过它调用简单的servlet并传递数据，我是使用URL和HttpURlConnection类。什么应该是servlet的URL路径

public class TestJava
{
    public static void main(String[] args) 
{
        try 
    {
     URL url=new URL("http://localhost:9865/TestingServlet/PushServlet");

    HttpURLConnection http_url =(HttpURLConnection)   
                                            url.openConnection();
     http_url.setRequestMethod("POST");
     http_url.setDoOutput(true); 
     http_url.setDoInput(true);
     InputStream response = http_url.getInputStream();
     System.out.println(" " +response);
     ObjectOutputStream objOut = new    
             ObjectOutputStream(http_url.getOutputStream());
     objOut.writeObject("hello");
     objOut.flush();
     objOut.close();

    } 

            catch (IOException e) {

        e.printStackTrace();
    }
       }
   }

这是servlet代码，我从java代码接收对象并显示
它在控制台上。

  public class PushServlet extends HttpServlet 
   {
        public void doPost(HttpServletRequest request, HttpServletResponse response) 
          throws  ServletException, IOException
         {

          try 
               {

                    System.out.println("HELLO This is servlet");
                ObjectInputStream objIn = new 
                    ObjectInputStream(request.getInputStream());
                TestJava p = null;
                p = (TestJava) objIn.readObject();
                System.out.println("Servlet received p: "+p);       
              } 
                 catch (Throwable e) 
                 {
                    e.printStackTrace(System.out);
             }
    }

我的web.xml就像这样

 <welcome-file-list>
 <welcome-file>
 Customer_Servlet
  </welcome-file>
  </welcome-file-list>
    <servlet>
    <servlet-name>PushServlet</servlet-name>
    <servlet-class>com.servlet.PushServlet</servlet-class>
   </servlet>
    <servlet-mapping>
     <servlet-name>PushServlet</servlet-name>
     <url-pattern>/PushServlet</url-pattern>
     </servlet-mapping>
     <session-config>
      <session-timeout>50</session-timeout>
      </session-config>
      </web-app>

当我试图在服务器上运行java代码，即Apache服务器时，我得到了错误HTTP状态404我无法找到为什么我收到此服务器错误我的代码都是关于从java应用程序调用servlet

 please help me guys .

Answer 1

所以回答你的问题：“什么应该是servlet的url路径？”我想你应该知道以下内容：

网址应为：

http://localhost:portNumber/nameOfTheContext/MappingOfTheServlet WHERE

portNumber = the port number of the server ( Apache has it by default to 80 but Apache Tomcat has it to 8080, so it's not 9865 unless you changed it from configuration file)
nameOfTheContext = the name of the folder/archive( with .WAR or .EAR extension) which you deployed to the server
MappingOfTheServlet = the mapping of the servlet which you put in web.xml. So if you have <url-pattern>/PushServlet</url-pattern> then the mapping is PushServlet.

所以说你的网址应该是：

http://localhost:8080/NameOfTheContext/PushServlet

如果不清楚在哪里可以找到NameOfTheContext告诉我们你是如何部署servlet的，那么我们可以帮助你。

稍后编辑：上下文的名称应为： JavaToServlet ，因为这是 .WAR 存档的名称。所以你的网址应该是： http://localhost:9865/JavaToServlet/PushServlet

Answer 2

来自网络上404 Error WiKi

的参考资料

当用户尝试关注损坏或死链接时，网站托管服务器通常会生成“404 Not Found”网页;

您可以通过以下链接更多地了解404错误 404 Not Found Error (What It Is and How To Fix It)

从Java应用程序调用Servlet时出现服务器错误

2 个答案: