查看通话记录时，Android应用程序在手机上崩溃

Question

我一直在研究一个读取通话记录的应用程序。我用过这段代码。

public String log_dump(ContentResolver con){

    StringBuffer sb = new StringBuffer();
    Cursor managedCursor = con.query(CallLog.Calls.CONTENT_URI, null,null, null, null);
    int number = managedCursor.getColumnIndex(CallLog.Calls.NUMBER);
    int type = managedCursor.getColumnIndex(CallLog.Calls.TYPE);
    int date = managedCursor.getColumnIndex(CallLog.Calls.DATE);
    int duration = managedCursor.getColumnIndex(CallLog.Calls.DURATION);
    sb.append("Call Details :");
    int i=0;
    while (managedCursor.moveToNext()) {
        String phNumber = managedCursor.getString(number);
        String callType = managedCursor.getString(type);
        String callDate = managedCursor.getString(date);
        Date callDayTime = new Date(Long.valueOf(callDate));
        String callDuration = managedCursor.getString(duration);
        String dir = null;
        int dircode = Integer.parseInt(callType);
        switch (dircode) {
        case CallLog.Calls.OUTGOING_TYPE:
            dir = "OUTGOING";
            break;

        case CallLog.Calls.INCOMING_TYPE:
            dir = "INCOMING";
            break;

        case CallLog.Calls.MISSED_TYPE:
            dir = "MISSED";
            break;
        }
        sb.append("\nPhone Number:--- " + phNumber + " \nCall Type:--- "
                + dir + " \nCall Date:--- " + callDayTime
                + " \nCall duration in sec :--- " + callDuration);
        sb.append("\n----------------------------------");

        if(i>10){
            break;
        }
        i = i+1;
    }
    managedCursor.close();
    return sb.toString();

}

当我在模拟器上运行它时工作正常。 但在我的手机上它崩溃了。你们可以帮助我吗？