How to send bytearray from Servlet to Midlet application?

[Archana Maharjan]

Hello everyone!
I'm trying to send bytes from servlet to midlet so that i could turn that bytes back to image and display in midlet.
Below are my codes!

//For Servlet

public void doPost(HttpServletRequest request, HttpServletResponse response) 
throws ServletException, IOException { 
String MIDP_USER_AGENT = "UNTRUSTED/1.0 Profile/MIDP-1.0 Configuration/CLDC-1.0"; 
String ua = request.getHeader("User-Agent"); 
String un=request.getParameter("ACT"); 
String pwsd=request.getParameter("PWD"); 
PrintWriter out = response.getWriter(); 
if(MIDP_USER_AGENT.equals(ua)){//Midlet 
out.println("screen capture"+request.getParameter("ACT")); 
out.println("password:"+request.getParameter("PWD")); 
} 
else{ 
response.setContentType("text/plain"); 
if(un.equals("project") && pwsd.equals("java")) 
{ 
try { 
//ScreenCapture is a class that captures DesktopScreen and returns its bytes 
byte[] imgByte=ScreenCapture.ScreenCapture(); 
out.print(imgByte); 
} catch (AWTException ex) { 
ex.printStackTrace(); 
} 
} 
else{ 
out.println("Sorry!Authentication not valid,Try Again!"); 
} 
} 
}  

//For Midlet

public void invokeServlet(String geturl, String account, String password) throws IOException { 
HttpConnection c = null; 
InputStream is = null; 
DataInputStream in=null; 
StringBuffer b = new StringBuffer(); 
byte[] imgByts; 
try { 
c = (HttpConnection) Connector.open(geturl + "?ACT=" + account + "&PWD=" + password); 
c.setRequestMethod(HttpConnection.GET); 
c.setRequestProperty("IF-Modified-Since", "20 Apr 2002 16:19:14 GMT"); 
c.setRequestProperty("User-Agent", "Profile/MIDP-1.0 Configuration/CLDC-1.0"); 
c.setRequestProperty("Content-Language", "en-US"); 
is = c.openDataInputStream(); 
int ch; 
while ((ch = is.read()) != -1) { 
b.append((char) ch); 
} 
imgByts=b.toString().getBytes(); 
Image img=Image.createImage(imgByts, 0, imgByts.length); 
ControlPCMidlet.canvas = new ImageCanvas(img);  
} catch (IOException ioe) { 
System.out.println("error 2:" + ioe); 
} finally { 
if (in != null) { 
in.close(); 
} 
if (is != null) { 
is.close(); 
} 
if (c != null) { 
c.close(); 
} 
} 
//Drawing picture in canvas 
ControlPCMidlet.display.setCurrent(ControlPCMidlet.canvas); 
} 

What should I do in above codes to get screencapture in midlet application? Thanking in advance....

[lokesh jain]

hi,
You need to treat midlet as the WebService client and you can call the method in the midlet then like this

   

public class DataBaseMidlet extends MIDlet implements Runnable, CommandListener{

    private Form form;
    private Display display;
    private Command result,exit;
    private Alert alert;
    private TextField textf,textf2,textf3,textf4;
    String DataQuery = "";
    String UsrNam ="";
    String Pswrd = "";
    String FilNam = "";
    DBconService_Stub dbss;
    
    public DataBaseMidlet()
    {
        display = Display.getDisplay(this);
        result = new Command("Ok", Command.OK, 1);
        exit = new Command("Exit", Command.SCREEN, 1);
        textf = new TextField("Enter Query   :", "", 100, TextField.ANY);
//       textf.getString()
//        System.out.println("value of textf >>> "+ textf.getString());
        textf2 = new TextField("Enter UserName   :", "", 20, TextField.ANY);
        textf3 = new TextField("Enter Password   :", "", 20, TextField.ANY | TextField.PASSWORD);
        textf4 = new TextField("Enter File Name :  ", "", 30, TextField.ANY);
        form = new Form("Connecting to Database");
        form.append(textf);
        form.append(textf2);
        form.append(textf3);
        form.append(textf4);
        form.addCommand(result);
        form.addCommand(exit);
        form.setCommandListener(this);
    }

    public void DataBaseResult()
    {
          System.out.println("inside Database Result");
        DataQuery = textf.getString();
        UsrNam = textf2.getString();
        Pswrd = textf3.getString();
        FilNam = textf4.getString();
        new Thread(this).start();
      
//        String st = null;
////        String st1 = textf.getString();
//        System.out.println("value of SQL Query >>> "+SQLquery);
//        System.out.println("value of Username  >>> "+Uname);
//        System.out.println("value of Password >>> "+Pass);
//        
//        st = FinalResult(SQLquery,Uname,Pass);
//        
//        return st;
    }
    public void run(){
        byte[] st1 = null;
        try{
             dbss = new DBconService_Stub();
            System.out.println("Values passed to Stub  >> "+DataQuery+
                    ">>>>     "+UsrNam+" >>>>>>   "+Pswrd+ ">>>>>>    "+FilNam);
//         st1
            st1         =    dbss.DB(DataQuery, UsrNam, Pswrd,FilNam);
//         System.out.println("value of STr >>   "+str);  
         System.out.println("value of ST1 >>   "+st1);
         String st2 = st1.toString();
         System.out.print("Value of ST2 >> "+st2);
         form.append(st2);
         display.setCurrent(form);
//            st1 = dbss.DB(Sq, Un, Pa);
            
        }catch(Exception ex){
            Alert serviceAlert = new Alert("Service Problem", "Try it later", null, AlertType.ERROR);
            serviceAlert.setTimeout(Alert.FOREVER);
            display.setCurrent(alert, form);
            System.out.print("Inside Catch  "+ex);
        }
//        return st1;
    }

    public void startApp() {
        
//        String str = DataBaseResult();
        display.setCurrent(form);
    }

    public void pauseApp() {
    }

    public void destroyApp(boolean unconditional) {
    }

    public void commandAction(Command cmd, Displayable disply) {
        //throw new UnsupportedOperationException("Not supported yet.");
        String label = cmd.getLabel();
try{
        if(label.equals("Exit"))
        {
            destroyApp(false);
            notifyDestroyed();
        }else if(label.equals("Ok"))
        {
            DataBaseResult();
        }
    }catch(Exception ex)
    {
        System.out.print("inside the CommantAction Exception  "+ex);
    }
    }
}

 

here dbss.DB(DataQuery, UsrNam, Pswrd,FilNam) is the method of the web service .java file.

regards
Lokesh

[Archana Maharjan]

Dear Lokesh!
Is there any possible way to display that screencapture without using the database?
Is the way I've passed the bytearray into midlet application correct?
Is the way I'm getting the bytearray in midlet application through servlet correct?
And I want to draw that image in the canvas of the midlet.
I have ControlPCMidlet midlet application, LoginValidateThread where run thread invokes the invokeservlet.
Wht should I do?

[lokesh jain]

hi Archana,
I have given you an example only, you can use the screen capture without use of Database things. To pass byteArray, you need to make the Midlet as client of the servlet. Yes, you can send byteArray from servlet to Midlet. You need to use Canvas class in midlet.

[lokesh jain]

Hi, Here I would like to give you a link, which performs servlet to midlet communication. webpage

I think your doubt will be cleared.

regards
Lokesh

[Archana Maharjan]

Thank you Lokesh ji. It is solved now!

[lokesh jain]

Hi,
That's good !! Can you tell me, how you did it. It will add to my knowledge base as well.


regards
Lokesh