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XAMPP 서버에 연결하고 아래 클래스로 MySQL 데이터베이스와 상호 작용하려고합니다. 그러나이 줄에 NullPointerException이 수신되었다는 오류 메시지가 표시됩니다.NullPointerError : 서버에 연결할 수 없습니다.
result = imService.createNewGroup(newGroupName);
CreateGroup 클래스에서. CreateGroup 클래스는 사용자가 Dialog에 텍스트를 입력하고 거기에서 서비스가 시작된 직후에 호출된다는 점에 유의해야합니다. 나는 서비스와 네트워크 연결에 대해 상당히 새로운 것이지만 적어도 .createGroup 명령을 보내려고하기 전에 서비스가 연결되어 있는지 확인할 수 있어야만하는 것이있다.
이 createGroup 클래스 : "이 createGroup"방법
public class CreateGroup extends Activity {
private static final String SERVER_RES_RES_SIGN_UP_SUCCESFULL = "1";
private static final String SERVER_RES_SIGN_UP_USERNAME_CRASHED = "2";
private Manager imService;
private Handler handler = new Handler();
String newGroupName;
public ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className, IBinder service) {
imService = ((MessagingService.IMBinder) service).getService();
}
public void onServiceDisconnected(ComponentName className) {
imService = null;
Toast.makeText(CreateGroup.this, R.string.local_service_stopped,
Toast.LENGTH_SHORT).show();
}
};
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
bindService(new Intent(CreateGroup.this, MessagingService.class),
mConnection, Context.BIND_AUTO_CREATE);
// Getting intent and info from the dialog
Intent i = getIntent();
Bundle extras = i.getExtras();
newGroupName = extras.getString("groupName");
Thread thread = new Thread() {
String result = new String();
@Override
public void run() {
// Send group name to the messaging
// service
try {
result = imService.createNewGroup(newGroupName);
} catch (NullPointerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Log.d("problem", "The value of result is " + result.toString());
handler.post(new Runnable() {
@Override
public void run() {
if (result == null) {
Toast.makeText(getApplicationContext(),
"It's null, not working", Toast.LENGTH_LONG)
.show();
}
if (result != null
&& result
.equals(SERVER_RES_RES_SIGN_UP_SUCCESFULL)) {
Toast.makeText(getApplicationContext(),
R.string.signup_successfull,
Toast.LENGTH_LONG).show();
// showDialog(SIGN_UP_SUCCESSFULL);
} else if (result != null
&& result
.equals(SERVER_RES_SIGN_UP_USERNAME_CRASHED)) {
Toast.makeText(getApplicationContext(),
R.string.signup_username_crashed,
Toast.LENGTH_LONG).show();
// showDialog(SIGN_UP_USERNAME_CRASHED);
} else // if
// (result.equals(SERVER_RES_SIGN_UP_FAILED))
{
Toast.makeText(getApplicationContext(),
R.string.signup_failed, Toast.LENGTH_LONG)
.show();
// showDialog(SIGN_UP_FAILED);
}
}
});
}
};
thread.start();
}
서버 케이스 :
case "createGroup":
$SQLtest = "insert into groups(groupName, uniqueGroup, createTime)
VALUES('TestGroup', 1234567891, NOW())";
error_log("$SQLtest", 3 , "error_log");
if($result = $db -> query($SQLtest))
{
$out = SUCCESSFUL;
}
else
{
$out = FAILED;
}
break;
메시징 서비스 및이 createGroup 방법 :
public class MessagingService extends Service implements Manager, Updater {
// private NotificationManager mNM;
public static String USERNAME;
public static final String TAKE_MESSAGE = "Take_Message";
public static final String FRIEND_LIST_UPDATED = "Take Friend List";
public static final String MESSAGE_LIST_UPDATED = "Take Message List";
public ConnectivityManager conManager = null;
private final int UPDATE_TIME_PERIOD = 15000;
private String rawFriendList = new String();
private String rawMessageList = new String();
SocketerInterface socketOperator = new Socketer(this);
private final IBinder mBinder = new IMBinder();
private String username;
private String password;
private boolean authenticatedUser = false;
// timer to take the updated data from server
private Timer timer;
private StorageManipulater localstoragehandler;
private NotificationManager mNM;
public class IMBinder extends Binder {
public Manager getService() {
return MessagingService.this;
}
}
@Override
public void onCreate() {
mNM = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
localstoragehandler = new StorageManipulater(this);
// Display a notification about us starting. We put an icon in the
// status bar.
// showNotification();
conManager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
new StorageManipulater(this);
// Timer is used to take the friendList info every UPDATE_TIME_PERIOD;
timer = new Timer();
Thread thread = new Thread() {
@Override
public void run() {
Random random = new Random();
int tryCount = 0;
while (socketOperator.startListening(10000 + random
.nextInt(20000)) == 0) {
tryCount++;
if (tryCount > 10) {
// if it can't listen a port after trying 10 times, give
// up...
break;
}
}
}
};
thread.start();
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
@Override
public String createNewGroup(String groupName) throws NullPointerException, UnsupportedEncodingException {
String params = "action=createGroup";
String result = socketOperator.sendHttpRequest(params);
return result;
}
}
감사합니다. – Sauron