ensure that debugging is enabled in your mainifest file as well as on your phone(if you are using one) if that break point crashes leave it there and place another one either in the calling activity or higher up in your code in that activity if you can.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of raqz Sent: Thursday, April 08, 2010 2:08 AM To: Android Developers Subject: [android-developers] Re: Trying to start a thread dedicated to sending and receiving data I tried placing the breakpoint right at the beginning of the code but the app crashes anyways. Am I supposed to run it in debug mode or something like that? On Apr 8, 1:55 am, "Tommy" <[email protected]> wrote: > Well in order to help I need to know what is causing the > NullPointerException. You need to set up a break point at the start of your > code and step through(f5) Keep an eye on the code b/c at some point it will > error out and the line of code it was on right before then is the one giving > the issue. > > -----Original Message----- > From: [email protected] > > [mailto:[email protected]] On Behalf Of raqz > Sent: Thursday, April 08, 2010 1:47 AM > To: Android Developers > Subject: [android-developers] Re: Trying to start a thread dedicated to > sending and receiving data > > The errors are as below > > java.lang.NullPointerException > at com.getFriends.ConnectSocket.sendData(ConnectSocket.java:43) > > I am not sure why its giving such an error. > > Please help. > > Thanks, > Raqeeb > > On Apr 8, 1:41 am, "Tommy" <[email protected]> wrote: > > What line does the debug catch the error? Have you stepped through to see > > what line causes the exception to throw? > > > -----Original Message----- > > From: [email protected] > > > [mailto:[email protected]] On Behalf Of raqz > > Sent: Thursday, April 08, 2010 1:37 AM > > To: Android Developers > > Subject: [android-developers] Trying to start a thread dedicated to > sending > > and receiving data > > > Hi, > > > I have a main class activity that does the task of sending control to > > other activities on click of a button. I am also starting a thread in > > the main class. This thread basically sets up a connection with the > > server and is active throughout the lifetime of the application. > > I have two functions in the thread class, send and receive data from > > server. Therefore, when the other activities need to send/receive data > > from server, they use those particular functions. > > First of all please let me know if what I am trying to do is fine as > > per the architecture of the operating system. If its fine, when I try > > to run the code, the app crashes and i see a NullPointerException and > > a RuntimeException in the DDMS log. > > Could some one please help me out in this or suggest a better way to > > implement the concept. > > Also, please be assured that, the other functionality of the code > > works perfectly fine. > > The main class code is as below > > [code] > > package com.getfriends; > > > import java.util.ArrayList; > > import java.util.Iterator; > > import java.util.List; > > import java.util.StringTokenizer; > > import android.app.Activity; > > import android.app.ListActivity; > > import android.os.Bundle; > > import android.widget.ArrayAdapter; > > import android.widget.ListView; > > import android.widget.Toast; > > > public class GetFriendsActivity extends Activity{ > > > private MyFriend obj= new MyFriend(); > > List<MyFriend> listOfFriends = new ArrayList<MyFriend>(); > > > int i=0; > > private String FName=null; > > private String LName=null; > > private String Latitude=null; > > private String Longitude=null; > > private String TimeStamp=null; > > public static ArrayList<String> namesArray=new > > ArrayList<String>(); > > > public void onCreate(Bundle savedInstanceState) { > > super.onCreate(savedInstanceState); > > Thread cThread= null; > > try{ > > cThread = new Thread(new ConnectSocket()); > > cThread.start();} > > catch (Exception e){ > > Toast.makeText(getBaseContext(), > > "Unable to start thread", > > Toast.LENGTH_LONG).show(); > > > } > > Toast.makeText(getBaseContext(), > > "Starting", > > Toast.LENGTH_LONG).show(); > > > try { > > getFriendsList(); > > } catch (Exception e) { > > Toast.makeText(getBaseContext(), > > "Unable to fetch friend list:"+e.getMessage(), > > Toast.LENGTH_LONG).show(); > > e.printStackTrace(); > > } > > try { > > displayFriendsList(); > > } catch (Exception e) { > > Toast.makeText(getBaseContext(), > > "Unable to display friend > list:"+e.getMessage() > > +e.getLocalizedMessage(), > > Toast.LENGTH_LONG).show(); > > e.printStackTrace(); > > } > > ConnectSocket socket = new ConnectSocket(); > > > socket.sendData("ABCDEF"); > > String k = socket.recieveData(); > > Toast.makeText(getBaseContext(), > > "Recieved from server:"+k, > > Toast.LENGTH_LONG).show(); > > > } > > > private void getFriendsList() { > > > String line[] = new String[3]; > > line[0]= > > "Abdul#Raqeeb#23.44#34.44#4.45"; > > line[1]= > > "Abdul#Azeez#33.44#44.44#5.45"; > > line[2]= > > "Kiral#Azeez#53.44#454.44#6.45"; > > for(int k=0;k<=2;k++){ > > StringTokenizer tokens=new > > StringTokenizer(line[k],"#"); > > try{ > > while(tokens.hasMoreTokens()) > > { > > FName=tokens.nextToken(); > > LName=tokens.nextToken(); > > Latitude=tokens.nextToken(); > > Longitude=tokens.nextToken(); > > TimeStamp=tokens.nextToken(); > > listOfFriends.add(new > > MyFriend(FName,LName,Latitude,Longitude,TimeStamp)); > > } > > } > > catch (Exception e){ > > Toast.makeText(this, > > "Some prob > > here:"+e.getLocalizedMessage(), > > > Toast.LENGTH_SHORT).show(); > > e.printStackTrace(); > > } > > } > > > } > > > } > > > [/code] > > > The code related to the thread is > > [code] > > package com.getfriends; > > > import java.io.BufferedReader; > > import java.io.DataOutputStream; > > import java.io.IOException; > > import java.io.InputStreamReader; > > import java.net.InetAddress; > > import java.net.Socket; > > > import android.util.Log; > > > public class ConnectSocket implements Runnable{ > > /** Called when the activity is first created. */ > > > public String fromServer=null; > > public static BufferedReader inFromServer=null; > > public static Socket clientSocket=null; > > public InetAddress address =null; > > public static DataOutputStream outToServer=null; > > > @Override > > public void run(){ > > > try { > > address = InetAddress.getByName("127.0.0.1"); > > Log.d("TCP", "C: Connecting..."); > > clientSocket = new Socket(address, 9999); > > outToServer = new > > DataOutputStream(clientSocket.getOutputStream()); > > inFromServer = new BufferedReader(new > > InputStreamReader(clientSocket.getInputStream())); > > } catch (Exception e) { > > System.out.println("Not Connected to the > internet"); > > } > > > } > > > public void sendData(String s){ > > try { > > if(s.equals(null)) s="hello"; > > Log.d("TCP", "C: Sending..."); > > outToServer.writeBytes(s+'#'); > > outToServer.flush(); > > } catch (IOException e) { > > // TODO Auto-generated catch block > > Log.d("TCP", "unable to send msg"); > > e.printStackTrace(); > > } > > > } > > > public String recieveData(){ > > try { > > fromServer = inFromServer.readLine(); > > if(fromServer.equals(null)) fromServer="bad luck"; > > } catch (IOException e) { > > // TODO Auto-generated catch block > > Log.d("TCP", "unable to send msg"); > > > > ... > > read more » -- You received this message because you are subscribed to the Google Groups "Android Developers" group. 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