Send JSON Request from blackberry application

问题:

how can i send JSON request from blackberry application that works as client to the server to get an information from the server to use them in BB application i use blackberry eclipse under windows 7

i try this code

public void loginRequest() throws IOException, JSONException{
    HttpConnection c = null;
    InputStream is = null;
    int rc;

    JSONObject postObject = new JSONObject();
    postObject.put("method", method);
    //postObject.put("params", Parameters);

    try{
        c = (HttpConnection)Connector.open(urlPath);

        // Set the request method and headers
        c.setRequestMethod(HttpConnection.GET);
        c.setRequestProperty("Content-Type", "application/json;charset=UTF-8");
        c.setRequestProperty("Content-Length", "" + (postObject.toString().length() - 2));
        c.setRequestProperty("method", "GET");

        // Getting the response code will open the connection,
        // send the request, and read the HTTP response headers.
        // The headers are stored until requested.
        rc = c.getResponseCode();
        if (rc != HttpConnection.HTTP_OK){
            throw new IOException("HTTP response code: " + rc);
        }

        is = c.openInputStream();

        // Get the length and process the data
        int len = (int)c.getLength();
        if (len > 0){
             int actual = 0;
             int bytesread = 0 ;
             byte[] data = new byte[len];
             while ((bytesread != len) && (actual != -1)){
                actual = is.read(data, bytesread, len - bytesread);
                bytesread += actual;
             }
             //Get the JSON String
            System.out.println(new String(data));
        }
        else{
            int ch;
            while ((ch = is.read()) != -1){
                //TODO
                /*
                process((byte)ch);
                */
            }
        }
    }catch (ClassCastException e){
        throw new IllegalArgumentException("Not an HTTP URL");
    }finally {
        if (is != null)
            is.close();
        if (c != null)
            c.close();
    }
   }

i call this method by run method in a thread

when the simulator reach (rc = c.getResponseCode();) running code stops

i debug the code and it stops when it reach this statement with this error

Local connection timed out after ~ 120000

any help

回答1:

When running the application in simulator, make sure you enabled the Launch Mobile Data System Connection Service (MDS-CS) with simulator in Eclipse's "Run Configurations" or "Debug Configurations"->"Simulator tab"->"General tab".

If it is not enabled, you should check this guide "Testing a BlackBerry device application with the BlackBerry Smartphone Simulator", particularly the "Testing a BlackBerry device application that uses an HTTP connection" section. To make a long story short, you have to enable the MDS-CS. After enabling it, you should restart your simulator. Here is a quote from this guide:

Start the BlackBerry MDS Connection Service when you start the BlackBerry Smartphone Simulator

1. In Eclipse®, on the Run menu, click Debug Configurations or Run Configurations.
2. Expand the BlackBerry Simulator item.
3. Complete one of the following tasks:
   • To work with an existing launch configuration, under BlackBerry Simulator, click a launch configuration.
   • To create a new launch configuration, right-click BlackBerry Simulator, select New.
4. Click the Simulator tab.
5. Click the General tab.
6. Select the Launch Mobile Data System Connection Service (MDS-CS) with simulator check box.
7. Click Apply.

Edit:
Alternatively, when using a simulator you can add ;deviceside=true suffix to the url that you pass to Connector.open(). By setting deviceside=true you specify that the underlying TCP connection should be opened directly from the handheld (simulator in your case), therefore BlackBerry MDS Connection Service will not be used. Here is a code snippet based on your code:

if (DeviceInfo.isSimulator()) {
    urlPath += ";deviceside=true";
} else {
    urlPath += connectionDependentSuffix; // suffix that is relevant to
                                          // the desired connection option
}
c = (HttpConnection)Connector.open(urlPath);

Hope this helps.