Possible Duplicate:
Trouble with reading phone state
I want to get a call state of phone in my application. I am doing one application in which , When user dial to a number, then my application should come to know whether other side phone is Busy, Not-reachable or power-off states etc. For this I used com.android.internal API's they are
Call.java<http://hi-android.info/src/com/android/internal/telephony/Call.java.html>,
CallManger.java<http://hi-android.info/src/com/android/internal/telephony/CallManager.java.html> and
Connection.java<http://hi-android.info/src/com/android/internal/telephony/Connection.java.html>. I created subclass of Call.java like this:
public class MyCall extends Call{
CallManager cm = CallManager.getInstance();
Connection c;
Phone mDefaultPhone;
private final ArrayList<Connection> emptyConnections = new ArrayList<Connection>();
int size;
List<Call> ringingCall = cm.getForegroundCalls();
@Override
public List<Connection> getConnections() {
System.out.println("**value of list***"+ringingCall.size());
if(ringingCall != null && !ringingCall.isEmpty()){
System.out.println("inside if****");
System.out.println("**call is not null***");
System.out.println("value of call"+ringingCall);
return ((MyCall) ringingCall).getConnections();
}
else{
System.out.println("**list is null***");
return emptyConnections;
}
}
@Override
public Phone getPhone() {
// TODO Auto-generated method stub
System.out.println("**inside getPhone***");
return null;
}
@Override
public void hangup() throws CallStateException {
// TODO Auto-generated method stub
System.out.println("**inside hangUp***");
}
@Override
public boolean isMultiparty() {
// TODO Auto-generated method stub
System.out.println("**inside isMultiparty***");
return false;
}
public Connection
getEarliestConnection() {
Connection myConn = new MyConnection();
System.out.println("inside EarliestConnection");
List<Connection> l;
long time = Long.MAX_VALUE;
Connection c;
Connection earliest = null;
l = getConnections();
System.out.println("value of connection is=="+l);
if (l == null) {
return null;
}else if ( l.size() == 0)
{
return null;
}
for (int i = 0, s = l.size() ; i < s ; i++) {
c = (Connection) l.get(i);
long t;
t = c.getCreateTime();
if (t < time) {
earliest = c;
time = t;
}
}
return earliest;
}
}
Here I am getting the ringingCall.size is 0 for that it is executing else part. And one more class is CallUpdate.java.
public class CallUpdate {
Call myCall = new MyCall();
CallManager cm = CallManager.getInstance();
public Object getCallFailedString(){
Connection myConn = myCall.getEarliestConnection();
System.out.println("myConn is ******"+myConn);
System.out.println("myCall is ******"+myCall);
if(myConn == null){
System.out.println("myConn is null ******");
return null;
}
else
{
Connection.DisconnectCause cause = myConn.getDisconnectCause();
System.out.println("myconn is not null ******"+cause);
switch(cause){
case BUSY :
System.out.println("inside busy");
break;
case NUMBER_UNREACHABLE :
System.out.println("inside un-reachable");
break;
case POWER_OFF :
System.out.println("inside power off");
break;
}
}
return myConn;
}
}
In this code getting myConn value is null. I called CallManger class is like this:
CallManager cm = CallManager.getInstance();
But when I print this getting null pointer exception. System.out.println("value of cm"+cm); why this exception? Can anybody tell me?
