I have an android app that has an incoming and outgoing call methods.
When I run the following method in PhonecallReceiver:
db.insert("CALLINCOME", null, messageValues);
I get an exception (see below). I have verified that the creation is successful. So, why does it crash on insert? note : Database created successfully
Caused by: java.lang.NullPointerException
at com.example.phamngochieu.recievercall.PhonecallReceiver.onIncomingCallStarted(PhonecallReceiver.java:59)
at com.example.phamngochieu.recievercall.PhonecallReceiver.onCallStateChanged(PhonecallReceiver.java:90)
at com.example.phamngochieu.recievercall.PhonecallReceiver.onReceive(PhonecallReceiver.java:48)
at android.app.ActivityThread.handleReceiver(ActivityThread.java:2392)
The following are the codes:
public class PhonecallReceiver extends BroadcastReceiver {
//The receiver will be recreated whenever android feels like it. We need a static variable to remember data between instantiations
private static int lastState = TelephonyManager.CALL_STATE_IDLE;
private static Date callStartTime;
private static boolean isIncoming;
private static String savedNumber; //because the passed incoming is only valid in ringing
public static SQLiteDatabase db;
@Override
public void onReceive(Context context, Intent intent) {
//We listen to two intents. The new outgoing call only tells us of an outgoing call. We use it to get the number.
if (intent.getAction().equals("android.intent.action.NEW_OUTGOING_CALL")) {
savedNumber = intent.getExtras().getString("android.intent.extra.PHONE_NUMBER");
}
else{
String stateStr = intent.getExtras().getString(TelephonyManager.EXTRA_STATE);
String number = intent.getExtras().getString(TelephonyManager.EXTRA_INCOMING_NUMBER);
int state = 0;
if(stateStr.equals(TelephonyManager.EXTRA_STATE_IDLE)){
state = TelephonyManager.CALL_STATE_IDLE;
}
else if(stateStr.equals(TelephonyManager.EXTRA_STATE_OFFHOOK)){
state = TelephonyManager.CALL_STATE_OFFHOOK;
}
else if(stateStr.equals(TelephonyManager.EXTRA_STATE_RINGING)){
state = TelephonyManager.CALL_STATE_RINGING;
}
onCallStateChanged(context, state, number);
}
}
//Derived classes should override these to respond to specific events of interest
protected void onIncomingCallStarted(Context ctx, String number, Date start)
{
ContentValues messageValues = new ContentValues();
messageValues.put("PHONENUMBER",number);
messageValues.put("TIME",start.toString());
Log.e(number, start.toString());
db.insert("CALLINCOME", null, messageValues);
Log.e("gọi đến","*******");
}
protected void onOutgoingCallStarted(Context ctx, String number, Date start)
{
ContentValues messageValues = new ContentValues();
messageValues.put("PHONENUMBER",number);
messageValues.put("TIME", start.toString());
Log.e(number, start.toString());
db.insert("CALLOUTCOME", null, messageValues);
Log.e("gọi đi", "*******");
}
protected void onIncomingCallEnded(Context ctx, String number, Date start, Date end){}
protected void onOutgoingCallEnded(Context ctx, String number, Date start, Date end){}
protected void onMissedCall(Context ctx, String number, Date start){}
//Deals with actual events
//Incoming call- goes from IDLE to RINGING when it rings, to OFFHOOK when it's answered, to IDLE when its hung up
//Outgoing call- goes from IDLE to OFFHOOK when it dials out, to IDLE when hung up
public void onCallStateChanged(Context context, int state, String number) {
if(lastState == state){
//No change, debounce extras
return;
}
switch (state) {
case TelephonyManager.CALL_STATE_RINGING:
isIncoming = true;
callStartTime = new Date();
savedNumber = number;
onIncomingCallStarted(context, number, callStartTime);
break;
case TelephonyManager.CALL_STATE_OFFHOOK:
//Transition of ringing->offhook are pickups of incoming calls. Nothing done on them
if(lastState != TelephonyManager.CALL_STATE_RINGING){
isIncoming = false;
callStartTime = new Date();
onOutgoingCallStarted(context, savedNumber, callStartTime);
}
break;
case TelephonyManager.CALL_STATE_IDLE:
//Went to idle- this is the end of a call. What type depends on previous state(s)
if(lastState == TelephonyManager.CALL_STATE_RINGING){
//Ring but no pickup- a miss
onMissedCall(context, savedNumber, callStartTime);
}
else if(isIncoming){
onIncomingCallEnded(context, savedNumber, callStartTime, new Date());
}
else{
onOutgoingCallEnded(context, savedNumber, callStartTime, new Date());
}
break;
}
lastState = state;
}
}
and Class DatabaseHelper bellow
public class DatabaseHelper extends SQLiteOpenHelper {
// tên của CSDL
private static final String DB_NAME = "message";
// Version của database
private static final int DB_VERSON =2;
public static SQLiteDatabase db;
public DatabaseHelper(Context context) {
super(context, DB_NAME, null, DB_VERSON);
}
public static long count;
@Override
public void onCreate(SQLiteDatabase db) {
// bảng này dùng để lưu tin nhắn đến và đi
this.db = db;
// bảng này dùng để lưu cuộc gọi đến
db.execSQL("CREATE TABLE CALLINCOME ("
+ "_id INTEGER PRIMARY KEY AUTOINCREMENT, "
+ "PHONENUMBER TEXT, "
+ "TIME TEXT);");
// bảng này lưu thông tin cuộc gọi đi
db.execSQL("CREATE TABLE CALLOUTCOME ("
+ "_id INTEGER PRIMARY KEY AUTOINCREMENT, "
+ "PHONENUMBER TEXT, "
+ "TIME TEXT);");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
and Manifestfile bellow
<receiver
android:name=".PhonecallReceiver"
android:enabled="true"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED"/>
<action android:name="android.intent.action.QUICKBOOT_POWERON" />
<action android:name="android.intent.action.PHONE_STATE" />
<action android:name="android.intent.action.NEW_OUTGOING_CALL" />
</intent-filter>
