Question

我有一个小程序需要向servlet提交分数，但它无法正常工作。

这是applet的代码

private URLConnection getConnection() throws MalformedURLException, IOException {
        URL serverAddress = null;
        URLConnection conn = null;
        serverAddress = new URL("http://localhost/GamesPortal/submitScore");
        conn = serverAddress.openConnection();
        conn.setDoOutput(true);
        conn.setRequestProperty("Content-Type", "application/x-java-serialized-object");
        return conn;
    }

    private void sendRecievedata(GameInfo info) {
        try {
            URLConnection c = this.getConnection();
            OutputStream os =  c.getOutputStream();
            ObjectOutputStream oos = new ObjectOutputStream(os);
            oos.writeObject(info);
            oos.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

这是servlet代码

    try {
        HttpSession s = request.getSession(true);

        response.setContentType("application/x-java-serialized-object");
        InputStream in = request.getInputStream();
        ObjectInputStream ois = new ObjectInputStream(in);
        GameInfo info = (GameInfo) ois.readObject();

        if (info.getUserId() > 0) {
            Scores score = new Scores();
            score.submitScore(info);
        }
    } catch (Exception ex) {
        ex.printStackTrace();
    } finally {
    }
    response.setContentType("text/html;charset=UTF-8");
    PrintWriter out = response.getWriter();
    try {
        out.println("<html>");
        out.println("<head>");
        out.println("<title>Servlet submitScore</title>");            
        out.println("</head>");
        out.println("<body>");
        out.println("<h1>Servlet submitScore at " + request.getContextPath() + "</h1>");
        out.println("</body>");
        out.println("</html>");
    } catch {
        ex.printStackTrace();
    } finally {            
        out.close();
    }

现在我尝试通过浏览器访问servlet，只是为了确保地址是正确的（确实如此），但出于某种原因，当我尝试从applet本身访问它时，它没有连接。（调试器甚至没有启动）。

（根据建议，将ex.printStackTrace（）;添加到每个try catch中，但我不知道我应该寻找什么或在哪里找到它）

调用applet的代码看起来类似于： http://roseindia.net/jsp/simple-jsp-example/applet-in-jsp.shtml

<jsp:plugin code="Pong.class" name="Games/Pong/Pong" type="applet" width="800" height="600">
    <jsp:params>
        <jsp:param name="userId" value="<%= user.getUserId()%>" ></jsp:param>
    </jsp:params>
</jsp:plugin>

有什么我在这里可以忽略的吗？

Answer 1

我设法让它发挥作用。

这是applet的代码：

    private URLConnection getServletConnection()
        throws MalformedURLException, IOException {
    URL urlServlet = new URL("http://localhost:8080/GamePortal/submitScore");
    URLConnection con = urlServlet.openConnection();
    con.setDoOutput(true);
    con.setRequestProperty(
            "Content-Type",
            "application/x-java-serialized-object");
    return con;

}

private void onSendData(GameInfo info) {

    try {
        // send data to the servlet
        URLConnection con = getServletConnection();
        OutputStream outstream = con.getOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(outstream);
        oos.writeObject(info);
        oos.flush();
        oos.close();
        // receive result from servlet
        InputStream instr = con.getInputStream();
        ObjectInputStream inputFromServlet = new ObjectInputStream(instr);
        String result = (String) inputFromServlet.readObject();
        //JOptionPane.showMessageDialog(null, result);
        inputFromServlet.close();
        instr.close();
    } catch (Exception ex) {
        ex.printStackTrace();
    }
}

这是servlet的代码：

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {        
    try {
        response.setContentType("application/x-java-serialized-object");
        // read a String-object from applet
        // instead of a String-object, you can transmit any object, which
        // is known to the servlet and to the applet
        InputStream in = request.getInputStream();
        ObjectInputStream inputFromApplet = new ObjectInputStream(in);
        GameInfo score = (GameInfo) inputFromApplet.readObject();
        System.out.println(score.getScore());

        GameInfo info = score;

        if (info.getUserId() > 0) {
            Scores instance = new Scores();
            instance.submitScore(info);
        }

        OutputStream outstr = response.getOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(outstr);
        oos.writeObject("reply");
        oos.flush();
        oos.close();
    } catch (ClassNotFoundException ex) {
    }
}

感谢您的帮助，请原谅我花太多时间回复。

Applet和Servlet通信

1 个答案: