如何修复java。伊奥。FileNotFoundException:url的响应：“404:未找到”http://localhost:7001/Socketwar/Servlet'

Question

我使用下面的代码从Java类中调用servlet：

  URL url = new URL( "http://localhost:7001/Socket-war/Servlet" );
  new BufferedReader(new InputStreamReader(url.openStream()));  

获得一个例外：

java.io.FileNotFoundException: Response: '404: Not Found' for url: 'http://localhost:7001/Socket-war/Servlet'  

一切都很好；我以前也在我的其他程序中使用过它；但现在提出例外

谁能告诉我为什么？？？任何建议或建议都是非常值得赞赏的

谢谢大家

Answer 1

这个答案是对聊天的回应

以下是我的servlet代码

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
          response.getWriter().println("Hello World");
            response.getWriter().flush();
            response.getWriter().close();
    }

下面是我的连接代码，它是有效的

public static void main(String[] args) throws IOException {
    System.setProperty("http.proxyHost", "proxy.***.com");
    System.setProperty("http.proxyPort", "####");
     Authenticator authenticator = new Authenticator() {
                    public PasswordAuthentication getPasswordAuthentication() {
                        return (new PasswordAuthentication("user",
                                "pwd".toCharArray()));
                    }
                };
    Authenticator.setDefault(authenticator);
     URL url = new URL( "http://localhost:8080/ImageCanvas/Servlet2" );
     BufferedReader br = new BufferedReader(new InputStreamReader(url.openStream()));
     String line;
     while((line=br.readLine())!= null){
         System.out.println(line);
         System.out.flush();
     }
     br.close();

}