applet 代码如下：

java.net.URL url1 = new java.net.URL("http://localhost:8080/platform/servlet/STOREDATA");
java.net.URLConnection con1 = url1.openConnection();
con1.setDoOutput(true);
con1.setUseCaches(false);
con1.setDoInput(true);         
con1.setRequestProperty("Content-type", "application/octet-stream");
PrintWriter out1 = new PrintWriter(con1.getOutputStream());
out1.println("this is test");
out1.flush();         
out1.close();


Servlet 代码如下:

BufferedReader in  = new BufferedReader(new InputStreamReader  (request.getInputStream()));
System.out.println(in.readLine());

tomcat 报错：2002-06-07 09:51:45 - Ctx(  ): 400 R( /) null

请帮忙.

This error occurs when the applet do not read servlet message, 
take a look at my example:


Appelt:

 private Object[][] getConfigInfo() throws MalformedURLException, IOException{
    URL url = new URL(/tech-qa-java/servletForecastUrl/index.html);
    URLConnection con = url.openConnection();
    con.setUseCaches(false);
    Object[][] configData;
     try
     {
        ObjectOutputStream outputToServlet = null;
        con.setDoOutput(true);
        outputToServlet = new ObjectOutputStream(con.getOutputStream());
        // serialize the object
        outputToServlet.writeObject("Get System Configuration");
        outputToServlet.flush();
        outputToServlet.close();
      }catch (IOException se){
           JOptionPane.showMessageDialog(null, "Can not connect to server!", "Server error", JOptionPane.PLAIN_MESSAGE);
      }

      try{
        InputStream in = con.getInputStream();
        ObjectInputStream objStream;
        objStream = new ObjectInputStream(in);
        configData = (Object[][])objStream.readObject();
        return configData;
      }catch(Exception re){
        //JOptionPane.showMessageDialog(null, "Can not connect to server!", "Server error", JOptionPane.PLAIN_MESSAGE);
      }
      return null;
 }