运行getWritableDatabase或getReadableDatabase时收到空错误。我知道这个问题已经提出过很多次了，但我花了7天的时间倾注所有的评论，没有任何运气。
这是第一个代码--HandleCall
package com.mintz.callmeback;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;
public class HandleCall extends Service implements Runnable {
String TAG = "HandleCall";
String phoneNum;
private NotificationManager notificationManager;
private Notification notification;
//CallMeBackApp CallApp = new CallMeBackApp();
Context context;
public HandleCall(String phone)
{
phoneNum = phone;
Log.i(TAG, "Constractor");
}
public void run() {
CallData callData = new CallData(this);
//CallMeBackApp callApp = new CallMeBackApp();
//callApp.endCall2();
Log.i(TAG, "run1"+phoneNum);
if (callData!=null)
Log.d(TAG,"callData is not null!");
以下是“if”语句中的问题，我读了很多关于“null”的答案，所以我尝试检查它是否为SQL任务，如你所见：
if ((callData != null)&&(callData.isPhoneInTheList1(phoneNum, this))){ Log.i(TAG, "run2");
SendSms.sendIt(phoneNum);
Log.i(TAG, "run3");
notificationManager = (NotificationManager) this.getSystemService(NOTIFICATION_SERVICE);
notification = new Notification(android.R.drawable.stat_notify_chat,"", 0);
sendCallNotification(phoneNum);
}
else{
Log.d(TAG, "didnt found the phone number");
}
}
private void sendCallNotification(String phone) {
Log.d(TAG, "sendCallNotification'ing");
Intent callIntent = new Intent(getApplicationContext(), MakeCall.class);
callIntent.putExtra("PhoneNumberToCallBack", phone);
PendingIntent pendingIntent = PendingIntent.getActivity(this, -1,callIntent ,PendingIntent.FLAG_UPDATE_CURRENT); //
this.notification.when = System.currentTimeMillis(); // time when it's happened
this.notification.flags |= Notification.FLAG_AUTO_CANCEL; // This flag tells the Notification manager to cancel this notification as soon as the user clicks on it.
CharSequence notificationTitle = this.getText(R.string.callBackToTitle); //
CharSequence notificationSummary = this.getString(R.string.callBackToMessage, phone);
this.notification.setLatestEventInfo(this, notificationTitle, notificationSummary, pendingIntent); //
this.notificationManager.notify(0, this.notification);
Log.d(TAG, "sendTimelineNotificationed");
}
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
}
和另一个班级：
package com.mintz.callmeback;
import android.content.Context;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class CallData {
static final String TAG = "CallData";
static final String DB_NAME = "PhoneToCallBack.db"; // database filename
static final int DB_VERSION = 1;
static final String TABLE = "PhoneToCallBack";
static final String C_ID = "_id";
static final String C_PHONE_NUMBER = "phone_number";
private static final String GET_ALL_ORDER_BY = C_PHONE_NUMBER + " DESC";
private static final String[] DB_PHONE_COLUMNS = { C_PHONE_NUMBER };
Context context;
// Constructor
public CallData(Context context) {
Log.i(TAG, "Initialized data");
this.context = context;
this.dbHelper = new DBHelper(context);
}
// DataBase Helper for the all App
public class DBHelper extends SQLiteOpenHelper {
Context context;
// Constructor
public DBHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
this.context = context;
}
// Not nead for now
//public DBHelper(Context context, String name, SQLiteDatabase.CursorFactory factory) {
// super(context, name, factory, DB_VERSION);
// this.context = context;
//}
@Override
public void onCreate(SQLiteDatabase db) {
Log.d(TAG, "Creating database: " + DB_NAME);
//String sql = context.getString(R.string.sql1);
//Log.d(TAG, "onCreated sql: " + sql);
db.execSQL("create table " + TABLE + " (" + C_ID + " int primary key, "
+ C_PHONE_NUMBER + " text)");
//db.execSQL(sql);
}
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("drop table if exists " + TABLE); // blow the old database away
Log.d(TAG, "onUpdated");
this.onCreate(db); // run onCreate to get new database
}
}//End of DBHelper Class
public DBHelper dbHelper;
public void close() {
this.dbHelper.close();
}
public void insertOrIgnore(ContentValues values) {
Log.d(TAG, "insertOrIgnore on " + values);
SQLiteDatabase db = this.dbHelper.getWritableDatabase();
try {
db.insertWithOnConflict(TABLE, null, values, SQLiteDatabase.CONFLICT_IGNORE);
} finally {
db.close();
}
}
/**
*
* @return Cursor where the columns are _id, phone_number
*/
public Cursor getPhoneList() {
SQLiteDatabase db = this.dbHelper.getReadableDatabase();
return db.query(TABLE, null, null, null, null, null, GET_ALL_ORDER_BY);
}
/**
* Deletes ALL the data
*/
public void delete() {
// Open Database
SQLiteDatabase db = this.dbHelper.getWritableDatabase();
// Delete the data
db.delete(TABLE, null, null);
// Close Database
db.close();
}
/**
*
* @param Phone number to check if exist
* @return True if the number is in the list
*/
public Boolean isPhoneInTheList(String phone) {
SQLiteDatabase db = dbHelper.getReadableDatabase();
Log.d(TAG, "befor query");
//Cursor cursor = db.query(TABLE, null, null, phone, null, null, null);
Cursor cursor = db.query("PhoneToCallBack", null, "phone_number=" + phone,null, null, null, null);
return (cursor.moveToFirst()) ; //Return True if find the Phone number in the DB
}
public Boolean isPhoneInTheList1(String phone, Context context) {
//DBHelper dbHelper1;
dbHelper = new DBHelper(context);
SQLiteDatabase database;
if (dbHelper != null)
Log.d(TAG,"dbHelper1 != null");
database = dbHelper.getWritableDatabase();
Log.d(TAG, "befor query");
Cursor cursor = database.query("PhoneToCallBack", null, "phone_number=" + phone,null, null, null, null);
return (cursor.moveToFirst()) ; //Return True if find the Phone number in the DB
}
}
这是我拨打电话并致电HandleCall时所得到的：
08-28 15:17:45.706: I/CallData(340): Initialized data
08-28 15:17:45.725: I/CallData(340): Initialized data
08-28 15:17:45.725: D/CallMeBackMainActivity(340): onCreate
08-28 15:17:45.826: D/CallMeBackMainActivity(340): onResume
08-28 15:17:45.826: D/CallMeBackMainActivity(340): Get the data from the database
08-28 15:17:45.886: D/CallMeBackMainActivity(340): Get the Cursor
08-28 15:19:21.495: D/PhoneServiceReceiver(340): the number is: 55555555
08-28 15:19:21.505: D/MyPhoneStateListener(340): RINGING from 55555555
08-28 15:19:21.535: I/HandleCall(340): Constractor
08-28 15:19:21.588: I/CallData(340): Initialized data
08-28 15:19:21.588: I/HandleCall(340): run155555555
08-28 15:19:21.595: D/HandleCall(340): callData is not null!
08-28 15:19:21.605: D/CallData(340): dbHelper1 != null
08-28 15:19:21.605: W/dalvikvm(340): threadid=9: thread exiting with uncaught exception (group=0x40015560)
08-28 15:19:21.638: E/AndroidRuntime(340): FATAL EXCEPTION: Thread-10
08-28 15:19:21.638: E/AndroidRuntime(340): java.lang.NullPointerException
08-28 15:19:21.638: E/AndroidRuntime(340): at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:203)
08-28 15:19:21.638: E/AndroidRuntime(340): at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:118)
08-28 15:19:21.638: E/AndroidRuntime(340): at com.mintz.callmeback.CallData.isPhoneInTheList1(CallData.java:133)
08-28 15:19:21.638: E/AndroidRuntime(340): at com.mintz.callmeback.HandleCall.run(HandleCall.java:43)
08-28 15:19:21.638: E/AndroidRuntime(340): at java.lang.Thread.run(Thread.java:1019)
08-28 15:19:21.895: W/IInputConnectionWrapper(340): showStatusIcon on inactive InputConnection
08-28 15:19:40.655: D/dalvikvm(340): GC_EXPLICIT freed 92K, 52% free 2599K/5379K, external 884K/1038K, paused 115ms
我很乐意得到任何帮助，我真的被卡住了！
答案 0 :(得分：0)
我认为您正在使用来自Activity的新调用初始化HandleCall。如果是这样，你就不能这样做。因为在这种情况下，您将没有HandleCall服务的上下文。这就是你崩溃的原因。
如果您正在执行new HandleCall，则无法通过
this
CallData callData = new CallData(this);
您必须传递一个由框架初始化的正确context而不是上面的行
编辑：
public HandleCall(String phone, Context ctx)
{
phoneNum = phone;
context = ctx;
Log.i(TAG, "Constractor");
}
现在使用
CallData callData = new CallData(context);
同时致电new HandleCall(phone, Activityname.this)