I am trying to send a text message to a phone and I get an error
Fail to send because of unknown reason. -java.io.IOException
import javax.microedition.io.Connector;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Form;
import javax.microedition.midlet.*;
import javax.wireless.messaging.MessageConnection;
import javax.wireless.messaging.TextMessage;
public class Midlet extends MIDlet {
Form form = new Form("Form");
Display display;
public void startApp()
{
display = Display.getDisplay(this);
display.setCurrent(form);
sendSMS("Hello from j2me");
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
private void sendSMS(String s) {
String destination = "+12234567890";
String addr = "sms://" + destination;
out("Setting up message");
MessageConnection sender = null;
try
{
try
{
sender = (MessageConnection) Connector.open(addr);
TextMessage msg = (TextMessage) sender.newMessage(MessageConnection.TEXT_MESSAGE);
msg.setPayloadText(s);
out("sending");
sender.send(msg);
out("sent successfully");
}
catch (Exception ex)
{
out("Error1:" + ex.getMessage() + " : " + ex.toString() + "\n\n");
}
finally
{
sender.close();
}
}
catch (Exception ex) {
//handle exception
out("Error2:" + ex.getMessage() + " : " + ex.toString() + "\n\n");
}
}
private void out(String str)
{
form.append(str + "\n");
}
}
Did you add permissions to your jad?
MIDlet-Permissions: javax.microedition.io.Connector.sms,javax.wireless.messaging.sms.send
All sorts of reasons:
No credit on PAYG phone
No mobile reception
SMS API blocked by handset operator
User rejected security prompt (this would cause a SecurityException)
Invalid mobile number
Related
Can someone please provide example code on how to use the Bluetooth cn1 library to read and write text data? I tried looking through the project source code (https://github.com/chen-fishbein/bluetoothle-codenameone) for example code, but could not find any that reads/writes text data using the appropriate methods. Those methods also don't have any Java docs.
Here's the code I'm using to send:
public void sendMessage(String message) {
if (Display.getInstance().isSimulator()) {
System.out.println(message);
} else {
// System.out.println("Sending message: " + message);
String b64WriteString = Base64.encode(message.getBytes());
try {
bt.write(new ActionListener() {
#Override
public void actionPerformed(ActionEvent evt) {
}
}, deviceAddress, services.get(0), sendDataCharacteristic, b64WriteString, false);
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
And here to receive:
private void registerNotifications() {
System.out.print("Registering notifications...");
try {
bt.subscribe(new ActionListener() {
#Override
public void actionPerformed(ActionEvent evt) {
JSONObject dataIncoming = (JSONObject) evt.getSource();
String base64Value = "";
try {
if (dataIncoming.getString("status").equals("subscribedResult")) {
base64Value = dataIncoming.getString("value");
}
} catch (JSONException e) {
e.printStackTrace();
}
String message = new String(Base64.decode(base64Value.getBytes()));
Display.getInstance().callSerially(new Runnable() {
#Override
public void run() {
messageReceived.set(message);
}
});
}
}, deviceAddress, services.get(0), receiveDataCharacteristic);
System.out.println("Registered");
System.out.println("Starting communication");
} catch (IOException e) {
System.err.println("Unable to register notifications " + e.getMessage());
e.printStackTrace();
}
}
I have fields defined for the service and characteristic UUID's. Also, the callSerially might not be needed anymore. I think I recall that the CN1LIB was updated to do that, but I don't remember for certain.
For that device, the service characteristic is "6E400001-B5A3-F393-E0A9-E50E24DCCA9E"
The sendCharacteristic is "0x0002"
The receiveCharacteristic is "0x0003"
After taking the suggestions of James H, and some more trial an error, I finally manage to get data transfer between the Adafruit's Bluefruit LE Friend working consistently, at least on an Android device. Not sure about iOS though, since I haven't tested it. Here are the critical code pieces needed.
First, you need the Service, TX and RX Characteristics UUIDs. These UUIDs were found here. Note, these don't need to be upper case.
public static final String UUID_SERVICE = "6e400001-b5a3-f393-e0a9-e50e24dcca9e";
public static final String UUID_RX = "6e400003-b5a3-f393-e0a9-e50e24dcca9e";
public static final String UUID_TX = "6e400002-b5a3-f393-e0a9-e50e24dcca9e";
Next, once you scanned and found the devices, call the connect() method to make the actual connection, and critically call the discover() method. Once the discover() callback gets called, then add the "subscriber" to receive data.
private void connect(String address) {
bleAddress = address; // set the global BLE address
if (!connected) {
// start an infinite progress dialog
final Dialog ip = new InfiniteProgress().showInifiniteBlocking();
try {
bt.connect(new ActionListener() {
#Override
public void actionPerformed(ActionEvent evt) {
ip.dispose();
Object obj = evt.getSource();
print("Connected to Bluetooth LE device ...\n" + obj, true);
// must be called on Android devices in order to load on the UUIDs, otherwise there is an error that service can't be found. Won't do anything on ios though?
discover();
connected = true;
}
}, address);
} catch (IOException ex) {
ip.dispose();
String message = "Error connecting to bluetooth device: " + address;
print(message + "\n" + ex.getMessage(), false);
}
} else {
String message = "BLE device already connected to: " + address;
print(message, false);
}
}
private void discover() {
try {
bt.discover(new ActionListener() {
#Override
public void actionPerformed(ActionEvent evt) {
print("BLE Information Received ...", true);
addSubscriber();
}
}, bleAddress);
} catch (Exception ex) {
print(ex.getMessage(), false);
}
// if we running on is add the subscriber here since the above bt call
// does nothing?
if (Display.getInstance().getPlatformName().equals("ios")) {
print("Adding subscriber for iOS Device", true);
addSubscriber();
}
}
private void addSubscriber() {
try {
bt.subscribe(new ActionListener() {
StringBuilder sb = new StringBuilder();
#Override
public void actionPerformed(ActionEvent evt) {
JSONObject dataIncoming = (JSONObject) evt.getSource();
String base64Value = "";
try {
if (dataIncoming.getString("status").equals("subscribedResult")) {
base64Value = dataIncoming.getString("value");
}
} catch (JSONException e) {
console.setText("Error reading data: " + e.getMessage());
}
String message = new String(Base64.decode(base64Value.getBytes()));
sb.append(message);
if (message.endsWith("\r\n")) {
processData(sb.toString());
sb = new StringBuilder();
}
}
}, bleAddress, UUID_SERVICE, UUID_RX);
String message = console.getText() + "\nSubcriber added ...";
console.setText(message);
} catch (IOException ex) {
String message = "Error Subscribing: " + ex.getMessage();
console.setText(message);
}
}
So this sets up the connection, discovers the services, and finally adds the subscriber method which receives the data, and critically uses a buffer to collect the received data until the CRLF characters are received.
However, another major issue I ran into was the default 23 byte send limit (maybe an Android only issue?) of the BLE specification. If you tried sending more than this, the connection just gets dropped with no meaningful error message being returned. To get around this, I used the technique suggested here, which entails splitting data into chunks of 20 byte arrays. Since we sending regular ASCII text, then 20 characters should be 20 bytes, so I just split the text into Strings 20 characters long. Not the most efficient by it works and it easier to debug.
private void sendText(final String data) {
try {
String b64String = Base64.encode(data.getBytes());
bt.write(new ActionListener() {
#Override
public void actionPerformed(ActionEvent evt) {
if(data.endsWith("\r\n")) {
print("Data sent ...", true);
}
}
}, bleAddress, UUID_SERVICE, UUID_TX, b64String, false);
} catch (IOException ex) {
String message = "Error sending: " + data + "\n"
+ UUID_SERVICE + "\n"
+ UUID_TX + "\n"
+ ex.getMessage();
print(message, false);
}
}
private void splitAndSend(String text) {
text += "\r\n";
// first split data in chunk size of 20 chracters
ArrayList<String> sl = new ArrayList<>();
char[] data = text.toCharArray();
int len = data.length;
int chunkSize = 20;
for (int i=0; i < len; i+= chunkSize) {
sl.add(new String(data, i, Math.min(chunkSize,len - i)));
}
// now send chunks amd wait 100 ms to prevent any erros
for(String word: sl) {
sendText(word);
try {
Thread.sleep(100);
} catch (InterruptedException ex) {}
}
}
The complete source code with GUI stuff can be found here, but this is definitely a work in progress.
I am new to android and java programming. I am try to write a program to read data via bluetooth.
I trying to pass a String apple which I decipher from my bluetooth input data from my thread to my UI for display CalibrationActivity.
I am using handler for the passing.
I keep getting force quit. Can anyone please advice me how can I solve this problem.
Below is my entire code of my extend Thread.
package com.android.backend.data.bluetooth;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.util.ArrayList;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import com.android.AutoActivity;
import com.android.CalibrationActivity;
import com.android.ui.UIManager;
public class Connection extends Thread {
final Connection tt = this;
private final String TAG = "Connection"; // Class name for logging
public boolean connected = false;
public BluetoothSocket bSocket = null;
public InputStream mmInStream = null;
public OutputStream mmOutStream = null;
public ArrayList<String> message = new ArrayList<String>();
public BluetoothDevice currentDevice = null;
public UIManager mgr;
public boolean connectFailure = false;
public boolean stopAutoConnect = false;
public String type = null;
public AutoActivity ff;
public void bsocketcancel() {
try {
bSocket.close();
} catch (IOException e) { }
}
public Connection(UIManager mgr, BluetoothDevice device, String message,
String type) {
this.mgr = mgr;
currentDevice = device;
this.message.add(message);
this.type = type;
}
public Connection(UIManager mgr, BluetoothDevice device, ArrayList<String> message,
String type) {
this.mgr = mgr;
currentDevice = device;
this.message = message;
this.type = type;
}
#Override
public void run() {
if (type.compareToIgnoreCase("Manual") == 0) {
Log.d("thread", "manual");
if (!connected)
connect(currentDevice);
if (bSocket != null){
for(String msg : message)
write(msg.getBytes());
}
mgr.hideConnectingProgressBox();
if(connected){
mgr.connectedDialog();
System.out.println("Maunal connected");
}
Log.d("thread", "hideprogressBox");
if (!connected)
mgr.showConnectionErrBox();
}
if (type.compareToIgnoreCase("auto") == 0){
Log.d("thread", "auto");
stopConnection();
int i = 0;
while (true) { //Set to 5 second
if (!connected)
connect(currentDevice);
if (bSocket != null){
for(String msg : message)
write(msg.getBytes());
}
mgr.hideConnectingProgressBox();
Log.d("thread", "hideprogressBox");
if (!connected) {
mgr.connecting();
}
if (connected) {
mgr.connectedDialog();
bsocketcancel();
System.out.println("Auto connected");
//BluetoothManager.getInstance().disconnectAll(); // cut all connection after transmit
break;
}
if(stopAutoConnect){
mgr.cancelconnecting();
break;
}
}
}
if (type.compareToIgnoreCase("calibrate") == 0) {
Log.d("thread", "calibrate");
if (!connected)
connect(currentDevice);
if (bSocket != null){
for(String msg : message)
write(msg.getBytes());
}
mgr.hideConnectingProgressBox();
if(connected){
mgr.connectedDialog();
mgr.msgsent();
System.out.println("Calibration connected");
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
int bytes;
String apple = "";
// Keep listening to the InputStream while connected
while (true) {
try {
// Read from the InputStream
bytes = mmInStream.read(buffer);
if ( bytes != -1){
while ((bytes==bufferSize)&&(buffer[bufferSize-1] != 0)){
apple = apple + "_" + new String(buffer, 0, bytes);
bytes = mmInStream.read(buffer);
}
apple = apple + new String(buffer, 0, bytes -1);
System.out.println("message " + apple);
//pass data to UI CalibrationActivity
System.out.println("message out " + apple);
Message msga = mhandler.obtainMessage();
Bundle bundle = new Bundle();
bundle.putString("key", apple);
msga.setData(bundle);
mhandler.sendMessage(msga);
}
} catch (IOException e) {
Log.e(TAG, "disconnected", e);
break;
}
}
}
Log.d("thread", "hideprogressBox");
if (!connected){
mgr.showConnectionErrBox();
}
}
}
public void connect(BluetoothDevice device) {
currentDevice = device;
BluetoothSocket tmp = null;
BluetoothManager.getInstance().getBluetoothAdapter().cancelDiscovery();
// Get a BluetoothSocket for a connection with the
// given BluetoothDevice
try {
// tmp = device
// .createRfcommSocketToServiceRecord(BluetoothManager.SerialPortServiceClass_UUID);
Method m = device.getClass().getMethod("createRfcommSocket",
new Class[] { int.class });
tmp = (BluetoothSocket) m.invoke(device, 1);
// } catch (IOException e) {
// Log.e(TAG, "create() failed", e);
// return;
} catch (Exception e) {
Log.e(TAG, "Socket connection failed", e);
return;
}
bSocket = tmp;
try {
bSocket.connect();
} catch (IOException e1) {
Log.e(TAG, "Connection err", e1);
connectFailure = true;
return;
}
if (tmp != null) {
// Get Input/output stream for Socket
try {
mmInStream = bSocket.getInputStream();
mmOutStream = bSocket.getOutputStream();
} catch (IOException e) {
Log.e(TAG, "temp sockets not created", e);
return;
}
}
connected = true;
connectFailure = false;
}
private Handler mhandler;
public void read(){
Log.i(TAG, "Read is running");
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
int bytes;
String a = "";
// Keep listening to the InputStream while connected
while (true) {
try {
// Read from the InputStream
bytes = mmInStream.read(buffer);
if ( bytes != -1){
while ((bytes==bufferSize)&&(buffer[bufferSize-1] != 0)){
a = a + new String(buffer, 0, bytes);
bytes = mmInStream.read(buffer);
}
a = a + new String(buffer, 0, bytes -1);
System.out.println("message " + a);
}
} catch (IOException e) {
Log.e(TAG, "disconnected", e);
break;
}
}
}
public void write(byte[] buffer) {
if (mmOutStream != null) {
try {
mmOutStream.write(buffer);
Log.d(TAG, "Message Sent");
} catch (IOException e) {
Log.e(TAG, "Exception during write", e);
}
} else {
//mgr.showConnectionErrBox();
}
}
public void stopConnection() {
try {
if(bSocket != null)
bSocket.close();
Log.e(TAG, "Connection closed");
} catch (IOException e) {
Log.e(TAG, "close() of connect socket failed", e);
}
}
public BluetoothDevice getCurrentDevice() {
return currentDevice;
}
public void setCurrentDevice(BluetoothDevice currentDevice) {
this.currentDevice = currentDevice;
}
public ArrayList<String> getMessage() {
return message;
}
public void setMessage(ArrayList<String> message) {
this.message = message;
}
}
Below is the affect portion
if(connected){
mgr.connectedDialog();
mgr.msgsent();
System.out.println("Calibration connected");
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
int bytes;
String apple = "";
// Keep listening to the InputStream while connected
while (true) {
try {
// Read from the InputStream
bytes = mmInStream.read(buffer);
if ( bytes != -1){
while ((bytes==bufferSize)&&(buffer[bufferSize-1] != 0)){
apple = apple + "_" + new String(buffer, 0, bytes);
bytes = mmInStream.read(buffer);
}
apple = apple + new String(buffer, 0, bytes -1);
System.out.println("message " + apple);
//pass data to UI CalibrationActivity
System.out.println("message out " + apple);
Message msga = mhandler.obtainMessage();
Bundle bundle = new Bundle();
bundle.putString("key", apple);
msga.setData(bundle);
mhandler.sendMessage(msga);
}
} catch (IOException e) {
Log.e(TAG, "disconnected", e);
break;
}
}
}
Below is the code for my Calibration Activity
package com.android;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import com.android.SimpleGestureFilter.SimpleGestureListener;
import com.android.backend.data.Playlist;
import com.android.backend.data.PlaylistManager;
import com.android.backend.data.SwitchBar;
import com.android.backend.data.bluetooth.BluetoothManager;
import com.android.backend.data.bluetooth.Connection;
import com.android.ui.UIManager;
import com.android.ui.playlist.PlaylistEntryList;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.text.Editable;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.view.Window;
import android.view.WindowManager.LayoutParams;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ToggleButton;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemLongClickListener;
//public class CalibrationActivity extends Activity{
public class CalibrationActivity extends Activity implements SimpleGestureListener{
String gotBread;
public void handleMessage(Message msg)
{ switch(msg.what){
case 2:
Bundle got = getIntent().getExtras();
gotBread = got.getString("key");
TextView aa = (TextView) this.findViewById(R.id.stringinput);
aa.setText(gotBread);
break;
}
}
private SimpleGestureFilter detector;
#Override
public boolean dispatchTouchEvent(MotionEvent me){
this.detector.onTouchEvent(me);
return super.dispatchTouchEvent(me);
}
#Override
public void onSwipe(int direction) {
// TODO Auto-generated method stub
//final MainActivity tt = this;
String str = "";
switch (direction) {
//case SimpleGestureFilter.SWIPE_RIGHT : str = "Swipe Right";
case SimpleGestureFilter.SWIPE_RIGHT : this.finish();
break;
case SimpleGestureFilter.SWIPE_LEFT : str = "Swipe Left";
break;
case SimpleGestureFilter.SWIPE_DOWN : str = "Swipe Down";
break;
case SimpleGestureFilter.SWIPE_UP : str = "Swipe Up";
break;
}
//Toast.makeText(this, str, Toast.LENGTH_SHORT).show();
}
#Override
public void onDoubleTap() {
// TODO Auto-generated method stub
//Toast.makeText(this, "Double Tap", Toast.LENGTH_SHORT).show();
//Do Nothing for now future development
}
private PlaylistManager playlistMgr;
private PlaylistEntryList playlistView; // Data for listview, stores current
// playlist in memory
public String createdNameList; // Indicated the name of currently Name of
// playlist that is being created
public Dialog dialog_customizePL, dialog_createPL, dialog_customizePLms; // Dialog boxes for
// Playlist creation
public UIManager uiMgr = new UIManager();
public String CONNECTED_DEVICE_MAC;
public String dialogboxtext;
public Connection Conn;
int i = 0;
protected void onPause() {
super.onPause();
//BluetoothManager.getInstance().disconnectAll();
unregisterReceiver(mRvcau); //Sequence is important
System.exit(0); // Kill off all thread to prevent connectiong lost popup
// I use system because is a calibration so I want user not to leave the activity else cannot calibrate
}
protected void onResume() { //restart bluetooth is accidently off it
super.onResume();
BluetoothManager.getInstance().init();
BluetoothManager.getInstance().getBluetoothAdapter().enable();
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED); // IntentFilter class is important to declare for below filter
registerReceiver(mRvcau,filter); // mRvcau is the location of logic, filter is message identify by android
filter = new IntentFilter(BluetoothDevice.ACTION_ACL_DISCONNECTED); // Future deveploment
registerReceiver(mRvcau,filter);
filter = new IntentFilter(BluetoothDevice.ACTION_ACL_DISCONNECT_REQUESTED); // Future deveploment
registerReceiver(mRvcau,filter);
filter = new IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED); // Future deveploment
registerReceiver(mRvcau,filter);
}
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.remotedevicecalibration);
detector = new SimpleGestureFilter(this,this); ////////////////// For Gesture
playlistMgr = PlaylistManager.getInstance();
initUI();
uiMgr.initPlayListUI(this);
}
int connect = 0; // Check connection
int disconnect = 0; // Check disconnection
int requestdisconnect = 0;
int connectstatuschanges = 0;
public BroadcastReceiver mRvcau = new BroadcastReceiver(){ // The new is instantiate the class **always read from the back
// The line from the back is creating an instantiate of this class
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) {
//AutoActivity.this.finish();
connect = 1; // prevent activity from exiting
System.out.println("ACTION_ACL_CONNECTED " + connect);
}
else
{
connect = 0;
System.out.println("ACTION_ACL_CONNECTED " + connect);
}
if (BluetoothDevice.ACTION_ACL_DISCONNECTED.equals(action)) { //future development
disconnect = 1;
System.out.println("ACTION_ACL_DISCONNECTED " + disconnect);
}
else
{
disconnect = 0;
System.out.println("ACTION_ACL_DISCONNECTED " + disconnect);
}
if (BluetoothDevice.ACTION_ACL_DISCONNECT_REQUESTED.equals(action)) { //future development
requestdisconnect = 1;
System.out.println("ACTION_ACL_DISCONNECT_REQUESTED " + requestdisconnect);
}
else
{
requestdisconnect = 0;
System.out.println("ACTION_ACL_DISCONNECT_REQUESTED " + requestdisconnect);
}
if (BluetoothDevice.ACTION_BOND_STATE_CHANGED.equals(action)) { //future development
connectstatuschanges = 1;
System.out.println("ACTION_BOND_STATE_CHANGED " + connectstatuschanges);
}
else
{
connectstatuschanges = 0;
System.out.println("ACTION_BOND_STATE_CHANGED " + connectstatuschanges);
}
}
};
/**
* Init layout component. Define Listener for Buttons and Dataset for
* ListViews
*/
#SuppressLint("ParserError")
public void initUI() {
Button Orange = (Button) findViewById(R.id.CalibrationOrange); // new method on test using image
Orange.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v){
// TODO Auto-generated method stub
activiteSingleConnection(20);
}
});
Button Blue = (Button) findViewById(R.id.CalibrationBlue); // new method on test using image icon to on the switch
Blue.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v){
// TODO Auto-generated method stub
activiteSingleConnection(21);
}
});
Button Green = (Button) findViewById(R.id.CalibrationGreen); // new method on test using image icon to on the switch
Green.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v){
// TODO Auto-generated method stub
activiteSingleConnection(22);
}
});
loadDataToMem();
}
public void activiteSingleConnection(int i) {
BluetoothManager btMgr = BluetoothManager.getInstance();
BluetoothDevice device = btMgr.getBluetoothAdapter().getRemoteDevice(
CONNECTED_DEVICE_MAC);
ArrayList<String> msg = new ArrayList<String>();
if(i == 20){
msg.add("N");
}
if(i == 21){
msg.add("J");
}
if(i == 22){
msg.add("I");
}
CharSequence fruit = null;
TextView aa = (TextView) this.findViewById(R.id.stringinput);
aa.setText(fruit);
btMgr.calibratesentMessage(uiMgr, device, msg);
}
public void loadDataToMem() {
try {
String str = "";
//StringBuffer buf = new StringBuffer();
FileInputStream input = this.openFileInput("bone.txt");
BufferedReader reader = new BufferedReader(new InputStreamReader(
input));
if (input != null) {
while ((str = reader.readLine()) != null) {
String[] buff = str.split(",");
TextView topView = (TextView) this
.findViewById(R.id.remotedevicecalibrationtextview1);
TextView bottomView = (TextView) this
.findViewById(R.id.remotedevicecalibrationtextView2);
topView.setText("Name : " + buff[0]);
bottomView.setText("Mac : " + buff[2]);
this.CONNECTED_DEVICE_MAC = buff[2];
Log.d("loadDataToMem", str);
}
}
input.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
Below are my log cat error message
09-13 10:50:33.640: W/dalvikvm(2086): threadid=9: thread exiting with uncaught exception (group=0x40015560)
09-13 10:50:33.667: E/AndroidRuntime(2086): FATAL EXCEPTION: Thread-10
09-13 10:50:33.667: E/AndroidRuntime(2086): java.lang.NullPointerException
09-13 10:50:33.667: E/AndroidRuntime(2086): at com.android.backend.data.bluetooth.Connection.run(Connection.java:196)
Hope someone can advice me how to solve. Thank You.
How to Implement a MIDlet that gets invoked when a SMS is sent to port 50000?
The code is not working. SMS can't be received on the phone, SMS is sent through the emulator (JAVA Me SDK).
What settings should be done to receive the SMS ?
my code:
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import java.io.IOException;
import javax.microedition.io.PushRegistry;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.MIDlet;
/**
* #author bonni
*/
public class Midletsms extends MIDlet implements CommandListener{
protected Display display;
//boolean started=false;
Form form = new Form("Welcome");
Command mCommandQuit;
public void startApp() {
String url = "sms://:50000";
try {
PushRegistry.registerConnection(url,this.getClass().getName(), "*");
// PushRegistry.registerConnection(url,"Midletsms.class", "*");
} catch (IOException ex) {
} catch (ClassNotFoundException ex) {
}
form.append("This midlet gets invoked when message is sent to port:50000");
display = Display.getDisplay(this);
display.setCurrent(form);
mCommandQuit = new Command("Quit", Command.EXIT, 0);
form.addCommand(mCommandQuit);
form.setCommandListener(this);
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
public void commandAction(Command c, Displayable d) {
// throw new UnsupportedOperationException("Not supported yet.");
String label = c.getLabel();
if(label.equals("Quit"))
{
destroyApp(false);
notifyDestroyed();
}
}
}
Not sure I fully understand the problem. But you need to read about PushRegistry.
So there are two types of push registration, static and dynamic.
The code example you have given uses dynamic registration. You will need to manually invoke this MIDlet at least once in order for the push registration to happen. (Aside: In your example you are doing this in the startApp method, this is a very bad idea! Push registration is a potentially blocking operation, and therefore should not be done in a lifecycle method such as startApp. You should do this in a new thread).
The alternative is static registration, where you include the push information in the jad. The push port will be registered when the MIDlet is installed, without the need to run it.
Finally, you say
sms is sent through the emulator
what does this mean? In order for the app to start you need to send an SMS on the relevant port number from another MIDlet (this could be on the same handset if you want).
I found this code on net from Jimmy's blog and it is perfectly working. You can try it your self,
SMSSender.java
public class SMSSender extends MIDlet implements CommandListener {
private Form formSender = new Form("SMS Sender");
private TextField tfDestination = new TextField("Destination", "", 20, TextField.PHONENUMBER);
private TextField tfPort = new TextField("Port", "50000", 6, TextField.NUMERIC);
private TextField tfMessage = new TextField("Message", "message", 150, TextField.ANY);
private Command cmdSend = new Command("Send", Command.OK, 1);
private Command cmdExit = new Command("Exit", Command.EXIT, 1);
private Display display;
public SMSSender() {
formSender.append(tfDestination);
formSender.append(tfPort);
formSender.append(tfMessage);
formSender.addCommand(cmdSend);
formSender.addCommand(cmdExit);
formSender.setCommandListener(this);
display = Display.getDisplay(this);
}
protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
}
protected void pauseApp() {
}
protected void startApp() throws MIDletStateChangeException {
display.setCurrent(formSender);
}
public void commandAction(Command c, Displayable d) {
if (c==cmdSend) {
SendMessage.execute(tfDestination.getString(), tfPort.getString(), tfMessage.getString());
} else if (c==cmdExit) {
notifyDestroyed();
}
}
}
class SendMessage {
public static void execute(final String destination, final String port, final String message) {
Thread thread = new Thread(new Runnable() {
public void run() {
MessageConnection msgConnection;
try {
msgConnection = (MessageConnection)Connector.open("sms://"+destination+":" + port);
TextMessage textMessage = (TextMessage)msgConnection.newMessage(
MessageConnection.TEXT_MESSAGE);
textMessage.setPayloadText(message);
msgConnection.send(textMessage);
msgConnection.close();
} catch (IOException e) {
e.printStackTrace();
}
}
});
thread.start();
}
}
SMSReceiver.java
public class SMSReceiver extends MIDlet implements CommandListener, MessageListener {
private Form formReceiver = new Form("SMS Receiver");
private TextField tfPort = new TextField("Port", "50000", 6, TextField.NUMERIC);
private Command cmdListen = new Command("Listen", Command.OK, 1);
private Command cmdExit = new Command("Exit", Command.EXIT, 1);
private Display display;
public SMSReceiver() {
formReceiver.append(tfPort);
formReceiver.addCommand(cmdListen);
formReceiver.addCommand(cmdExit);
formReceiver.setCommandListener(this);
display = Display.getDisplay(this);
}
protected void destroyApp(boolean unconditional)
throws MIDletStateChangeException {
}
protected void pauseApp() {
}
protected void startApp() throws MIDletStateChangeException {
display.setCurrent(formReceiver);
}
public void commandAction(Command c, Displayable d) {
if (c==cmdListen) {
ListenSMS sms = new ListenSMS(tfPort.getString(), this);
sms.start();
formReceiver.removeCommand(cmdListen);
} else if (c==cmdExit) {
notifyDestroyed();
}
}
public void notifyIncomingMessage(MessageConnection conn) {
Message message;
try {
message = conn.receive();
if (message instanceof TextMessage) {
TextMessage tMessage = (TextMessage)message;
formReceiver.append("Message received : "+tMessage.getPayloadText()+"\n");
} else {
formReceiver.append("Unknown Message received\n");
}
} catch (InterruptedIOException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
class ListenSMS extends Thread {
private MessageConnection msgConnection;
private MessageListener listener;
private String port;
public ListenSMS(String port, MessageListener listener) {
this.port = port;
this.listener = listener;
}
public void run() {
try {
msgConnection = (MessageConnection)Connector.open("sms://:" + port);
msgConnection.setMessageListener(listener);
} catch (IOException e) {
e.printStackTrace();
}
}
}
I've spent long on this but no success yet. In my application to capture image and send to the server, I get NullPointerException below;
java.lang.NullPointerException: 0
at Files.CameraMIDlet.snap(CameraMIDlet.java:120)
at Files.CameraForm.commandAction(CameraForm.java:116)
at javax.microedition.lcdui.Display$ChameleonTunnel.callScreenListener(), bci=46
at com.sun.midp.chameleon.layers.SoftButtonLayer.processCommand(), bci=74
at com.sun.midp.chameleon.layers.SoftButtonLayer.soft2(), bci=173
at com.sun.midp.chameleon.layers.SoftButtonLayer.keyInput(), bci=78
at com.sun.midp.chameleon.CWindow.keyInput(), bci=38
at javax.microedition.lcdui.Display$DisplayEventConsumerImpl.handleKeyEvent(), bci=17
at com.sun.midp.lcdui.DisplayEventListener.process(), bci=277
at com.sun.midp.events.EventQueue.run(), bci=179
at java.lang.Thread.run(Thread.java:722)
The errors happen at byte[] image = videoControl.getSnapshot("encoding = jpeg"); in the CameraMIDlet and also at midlet.snap(); in the CameraForm, in the code below.
The code for CameraForm is here:
package Files;
import javax.microedition.media.*;
import javax.microedition.lcdui.*;
import javax.microedition.media.control.*;
import java.io.IOException;
class CameraForm extends Form implements CommandListener {
private final CameraMIDlet midlet;
private final Command exitCommand;
private Command captureCommand = null;
private Command showImageCommand = null;
private Player player = null;
private static VideoControl videoControl = null;
private boolean active = false;
private StringItem messageItem;
public CameraForm(CameraMIDlet midlet) {
super("Camera");
this.midlet = midlet;
messageItem = new StringItem("Message", "start");
append(messageItem);
exitCommand = new Command("EXIT", Command.EXIT, 1);
addCommand(exitCommand);
setCommandListener(this);
try {
//creates a new player and set it to realize
player = Manager.createPlayer("capture://video");
player.realize();
//Grap the Video control and set it to the current display
videoControl = (VideoControl) (player.getControl("VideoControl"));
if (videoControl != null) {
append((Item) (videoControl.initDisplayMode(
VideoControl.USE_GUI_PRIMITIVE, null)));
captureCommand = new Command("CAPTURE", Command.SCREEN, 1);
addCommand(captureCommand);
messageItem.setText("OK");
} else {
messageItem.setText("No video control");
}
} catch (IOException ioe) {
messageItem.setText("IOException: " + ioe.getMessage());
} catch (MediaException me) {
messageItem.setText("Media Exception: " + me.getMessage());
} catch (SecurityException se) {
messageItem.setText("Security Exception: " + se.getMessage());
}
}
* the video should be visualized on the sreen
* therefore you have to start the player and set the videoControl visible
synchronized void start() {
if (!active) {
try {
if (player != null) {
player.start();
}
if (videoControl != null) {
videoControl.setVisible(true);
//midlet.snap();
}
} catch (MediaException me) {
messageItem.setText("Media Exception: " + me.getMessage());
} catch (SecurityException se) {
messageItem.setText("Security Exception: " + se.getMessage());
}
active = true;
}
}
* to stop the player. First the videoControl has to be set invisible
* than the player can be stopped
synchronized void stop() {
if (active) {
try {
if (videoControl != null) {
videoControl.setVisible(false);
}
if (player != null) {
player.stop();
}
} catch (MediaException me) {
messageItem.setText("Media Exception: " + me.getMessage());
}
active = false;
}
}
* on the captureCommand a picture is taken and transmited to the server
public void commandAction(Command c, Displayable d) {
if (c == exitCommand) {
midlet.cameraFormExit();
} else {
if (c == captureCommand) {
midlet.snap();
}
}
}
}
The code for CameraMIDlet is below:
package Files;
import java.io.*;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.io.*;
import javax.microedition.media.control.*;
import java.io.IOException;
import javax.microedition.media.MediaException;
public class CameraMIDlet extends MIDlet {
private CameraForm cameraSave = null;
private DisplayImage displayImage = null;
CameraForm captureThread;
private static VideoControl videoControl;
private StringItem messageItem;
public CameraMIDlet() {
}
/*
* startApp()
* starts the MIDlet and generates cameraSave, displayImage, database
*
**/
public void startApp() {
Displayable current = Display.getDisplay(this).getCurrent();
if (current == null) {
//first call
cameraSave = new CameraForm(this);
displayImage = new DisplayImage(this);
Display.getDisplay(this).setCurrent(cameraSave);
cameraSave.start();
} else {
//returning from pauseApp
if (current == cameraSave) {
cameraSave.start();
}
Display.getDisplay(this).setCurrent(current);
}
}
public void pauseApp() {
if (Display.getDisplay(this).getCurrent() == cameraSave) {
cameraSave.stop();
}
}
public void destroyApp(boolean unconditional) {
if (Display.getDisplay(this).getCurrent() == cameraSave) {
cameraSave.stop();
}
}
private void exitRequested() {
destroyApp(false);
notifyDestroyed();
}
void cameraFormExit() {
exitRequested();
}
/**
* restart the camera again
*
*/
void displayCanvasBack() {
Display.getDisplay(this).setCurrent(cameraSave);
cameraSave.start();
}
/**
* the byte[] of the image should be transmitted to a server
*
**/
void buildHTTPConnection(byte[] byteImage) {
displayImage.setImage(byteImage);
Display.getDisplay(this).setCurrent(displayImage);
HttpConnection hc = null;
OutputStream out = null;
try {
//enode the image data by the Base64 algorithm
String stringImage = Base64.encode(byteImage);
// URL of the Sevlet
String url = new String(
"http://ip-adress:8080/C:/Users/HASENDE/Documents/NetBeansProjects/Mobile/pics");
// Obtain an HTTPConnection
hc = (HttpConnection) Connector.open(url);
// Modifying the headers of the request
hc.setRequestMethod(HttpConnection.POST);
// Obtain the output stream for the HttpConnection
out = hc.openOutputStream();
out.write(stringImage.getBytes());
} catch (IOException ioe) {
StringItem stringItem = new StringItem(null, ioe.toString());
} finally {
try {
if (out != null)
out.close();
if (hc != null)
hc.close();
} catch (IOException ioe) {
}
}
// ** end network
}
/**
* stop the camera, show the captured image and transmit the image to a server
**/
void transmitImage(byte[] image) {
cameraSave.stop();
Display.getDisplay(this).setCurrent(displayImage);
buildHTTPConnection(image);
}
public void snap(){
try {
byte[] image = videoControl.getSnapshot("encoding = jpeg");
transmitImage(image);
messageItem.setText("Ok");
} catch (MediaException me) {
messageItem.setText("Media Exception: " + me.getMessage());
}
}
}
By identifying the statement that throws NPE you get 99% close to finding the bug:
byte[] image = videoControl.getSnapshot("encoding = jpeg");
NPE in above statement means videoControl is null. Now if you look at it closer, you may notice that in CameraMIDlet, videoControl is initialized with null and never changes to anything else - that's why you are getting NPE. By the way, from CameraForm code it looks like you intended to use videoControl object that is defined there, didn't you.
Side note. CameraForm seems to be designed to used in multiple threads (there are synchronized modifiers) - if this is the case, you better make sure that videoControl is also obtained from it in a synchronized way. Also in that case, add volatile modifier in definition of active flag:
private volatile boolean active = false; // in CameraForm
For Capturing photo use canvas instead of Form,
Check follwing code for Photo Capture
public class ImageCaptureCanvas extends Canvas {
UrMidlet midlet;
VideoControl videoControl;
Player player;
SnapShotCanvas snap;
private Display display;
public ImageCaptureCanvas(UrMidlet midlet) throws MediaException {
this.midlet = midlet;
this.display = Display.getDisplay(midlet);
this.setFullScreenMode(true);
try {
player = Manager.createPlayer("capture://image");
player.realize();
videoControl = (VideoControl) player.getControl("VideoControl");
} catch (Exception e) {
dm(e.getClass().getName());
}
videoControl.initDisplayMode(VideoControl.USE_DIRECT_VIDEO, this);
try {
videoControl.setDisplayLocation(0,0);
videoControl.setDisplaySize(getWidth(), getHeight());
} catch (MediaException me) {
try {
videoControl.setDisplayFullScreen(true);
} catch (MediaException me2) {
}
}
dm("icc10");
videoControl.setVisible(true);
dm("icc11");
player.start();
this.display.setCurrent(this);
}
public void dm(String message) {
Form form = new Form("Error");
form.append(message);
display.setCurrent(form);
}
public void paint(Graphics g) {
}
protected void keyPressed(int keyCode) {
boolean prv=false;
int actn=getGameAction(keyCode);
switch (keyCode) {
case KEY_NUM5:
prv=true;
Thread t = new Thread() {
public void run() {
try {
byte[] raw = videoControl.getSnapshot(null);
Image image = Image.createImage(raw, 0, raw.length);
snap = new SnapShotCanvas(image);
display.setCurrent(snap);
} catch (Exception e) {
dm(e.getClass().getName() + " " + e.getMessage());
}
}
};
t.start();
break;
}
if(!prv){
switch (actn) {
case Canvas.FIRE:
Thread t1 = new Thread() {
public void run() {
try {
byte[] raw = videoControl.getSnapshot(null);
Image image = Image.createImage(raw, 0, raw.length);
snap = new SnapShotCanvas(image);
display.setCurrent(snap);
} catch (Exception e) {
dm(e.getClass().getName() + " " + e.getMessage());
}
}
};
t1.start();
break;
}
}
}
}
SnapShotCanvas Code here
class SnapShotCanvas extends Canvas {
private Image image;
public SnapShotCanvas(Image image) {
this.image = image;
setFullScreenMode(true);
}
public void paint(Graphics g) {
g.drawImage(image, getWidth() / 2, getHeight() / 2, Graphics.HCENTER | Graphics.VCENTER);
}
}
i have the following code which is giving me error:
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Vector;
import javax.bluetooth.BluetoothStateException;
import javax.bluetooth.DeviceClass;
import javax.bluetooth.DiscoveryAgent;
import javax.bluetooth.DiscoveryListener;
import javax.bluetooth.LocalDevice;
import javax.bluetooth.RemoteDevice;
import javax.bluetooth.ServiceRecord;
import javax.bluetooth.UUID;
import javax.microedition.io.Connector;
import javax.microedition.io.StreamConnection;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.List;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
public class DeviceClientCOMM implements DiscoveryListener, CommandListener {
static final boolean DEBUG = false;
static final String DEBUG_address = "0013FDC157C8"; // N6630
protected UUID uuid = new UUID(0x1101); // serial port profile
protected int inquiryMode = DiscoveryAgent.GIAC; // no pairing is needed
protected int connectionOptions = ServiceRecord.NOAUTHENTICATE_NOENCRYPT;
protected int stopToken = 255;
private Command backCommand = new Command("Back", Command.BACK, 1);
protected Form infoArea = new Form("Bluetooth Client");
protected Vector deviceList = new Vector();
private CameraMIDlet mymidlet;
private byte[] imag;
public DeviceClientCOMM(CameraMIDlet m, byte[] imag) {
mymidlet = m;
this.imag = imag;
infoArea.setCommandListener(this);
infoArea.addCommand(backCommand);
try {
startApp();
} catch (MIDletStateChangeException ex) {
ex.printStackTrace();
}
}
protected void startApp() throws MIDletStateChangeException {
makeInformationAreaGUI();
if (DEBUG) // skip inquiry in debug mode
{
startServiceSearch(new RemoteDevice(DEBUG_address) {
});
} else {
try {
startDeviceInquiry();
} catch (Throwable t) {
log(t);
}
}
}
private void startDeviceInquiry() {
try {
log("Start inquiry method - this will take few seconds...");
DiscoveryAgent agent = getAgent();
agent.startInquiry(inquiryMode, this);
} catch (Exception e) {
log(e);
}
}
public void deviceDiscovered(RemoteDevice btDevice, DeviceClass cod) {
log("A device discovered (" + getDeviceStr(btDevice) + ")");
deviceList.addElement(btDevice);
}
public void inquiryCompleted(int discType) {
log("Inquiry compeleted. Please select device from combo box.");
makeDeviceSelectionGUI();
}
private void startServiceSearch(RemoteDevice device) {
try {
log("Start search for Serial Port Profile service from " + getDeviceStr(device));
UUID uuids[] = new UUID[]{uuid};
getAgent().searchServices(null, uuids, device, this);
} catch (Exception e) {
log(e);
}
}
public void servicesDiscovered(int transId, ServiceRecord[] records) {
log("Service discovered.");
for (int i = 0; i < records.length; i++) {
ServiceRecord rec = records[i];
String url = rec.getConnectionURL(connectionOptions, false);
handleConnection(url);
}
}
public void serviceSearchCompleted(int transID, int respCode) {
String msg = null;
switch (respCode) {
case SERVICE_SEARCH_COMPLETED:
msg = "the service search completed normally";
break;
case SERVICE_SEARCH_TERMINATED:
msg = "the service search request was cancelled by a call to DiscoveryAgent.cancelServiceSearch()";
break;
case SERVICE_SEARCH_ERROR:
msg = "an error occurred while processing the request";
break;
case SERVICE_SEARCH_NO_RECORDS:
msg = "no records were found during the service search";
break;
case SERVICE_SEARCH_DEVICE_NOT_REACHABLE:
msg = "the device specified in the search request could not be reached or the local device could not establish a connection to the remote device";
break;
}
log("Service search completed - " + msg);
}
private void handleConnection(final String url) {
Thread echo = new Thread() {
public void run() {
StreamConnection stream = null;
InputStream in = null;
OutputStream out = null;
try {
log("Connecting to server by url: " + url);
stream = (StreamConnection) Connector.open(url);
log("Bluetooth stream open.");
// InputStream in = stream.openInputStream();
out = stream.openOutputStream();
in = stream.openInputStream();
startReadThread(in);
// String stringImage = Base64.encode(imag);
log("Start echo loop.");
out.write(imag);
out.flush();
// out.flush();
// stream.close();
} catch (IOException e) {
log(e);
} finally {
log("Bluetooth stream closed.");
if (out != null) {
try {
out.close();
stream.close();
logSet("Image Transfer done\n----------------\n\nWaiting for results...");
} catch (IOException e) {
log(e);
}
}
}
}
};
echo.start();
}
private void startReadThread(final InputStream in) {
Thread reader = new Thread() {
public void run() {
byte[] s = new byte[512];
//boolean flag = true;
try {
while (true) {
int r = in.read(s);
if (r != -1) {
logSet(new String(s, 0, r));
} else {
break;
}
Thread.sleep(200);
}
} catch (Throwable e) {
log(e);
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
}
}
}
}
};
reader.start();
}
private void makeInformationAreaGUI() {
infoArea.deleteAll();
Display.getDisplay(mymidlet).setCurrent(infoArea);
}
private void makeDeviceSelectionGUI() {
final List devices = new List("Select a device", List.IMPLICIT);
for (int i = 0; i < deviceList.size(); i++) {
devices.append(
getDeviceStr((RemoteDevice) deviceList.elementAt(i)), null);
}
devices.setCommandListener(new
CommandListener( ) {
public void commandAction(Command arg0,
Displayable arg1)
{
makeInformationAreaGUI();
startServiceSearch((RemoteDevice) deviceList.elementAt(devices.getSelectedIndex()));
}
});
Display.getDisplay(mymidlet).setCurrent(devices);
}
synchronized private void log(String msg) {
infoArea.append(msg);
infoArea.append("\n\n");
}
synchronized private void logSet(String msg) {
infoArea.deleteAll();
infoArea.append(msg);
infoArea.append("\n\n");
}
private void log(Throwable e) {
log(e.getMessage());
}
private DiscoveryAgent getAgent() {
try {
return LocalDevice.getLocalDevice().getDiscoveryAgent();
} catch (BluetoothStateException e) {
throw new Error(e.getMessage());
}
}
private String getDeviceStr(RemoteDevice btDevice) {
return getFriendlyName(btDevice) + " - 0x" + btDevice.getBluetoothAddress();
}
private String getFriendlyName(RemoteDevice btDevice) {
try {
return btDevice.getFriendlyName(false);
} catch (IOException e) {
return "no name available";
}
}
public void commandAction(Command arg0, Displayable arg1) {
mymidlet.DisplayMainList();
}
}
the errors are
C:\Documents and Settings\admin\My Documents\NetBeansProjects\DeviceClientCOMM\src\DeviceClientCOMM.java:51: cannot find symbol
symbol : class CameraMIDlet
location: class DeviceClientCOMM
private CameraMIDlet mymidlet;
C:\Documents and Settings\admin\My Documents\NetBeansProjects\DeviceClientCOMM\src\DeviceClientCOMM.java:54: cannot find symbol
symbol : class CameraMIDlet
location: class DeviceClientCOMM
public DeviceClientCOMM(CameraMIDlet m, byte[] imag)
You don't have an import for CameraMIDlet, so the compiler doesn't know which class you mean.
Assuming you've got an appropriate classpath entry, you should just be able to add the right import and it should be fine.
Are you sure CameraMIDlet exists for your use though? I can see some sample code in JSR-135, but I'm not sure it's a full API to be used...