我正在尝试在没有网络时将数据插入数据库，但它给了我NullPointerException。当它上线时，它会给其他人一些并崩溃我的应用程序。
LogCat错误
10-13 01:27:07.614: E/Service(13862): Service Created..
10-13 01:27:08.054: E/Service Started(13862): Successful
10-13 01:27:08.094: E/Insertion(13862): java.lang.NullPointerException
10-13 01:27:09.134: E/Service Network(13862): Network is offline
10-13 01:27:14.174: E/Service Network(13862): Network is offline
10-13 01:28:29.154: E/Service Network(13862): Network is offline
10-13 01:28:35.924: E/Service Network(13862): Network is offline
10-13 01:28:39.174: E/Service Network(13862): Network is online
10-13 01:28:39.204: E/AndroidRuntime(13862): FATAL EXCEPTION: Timer-0
10-13 01:28:39.204: E/AndroidRuntime(13862): java.lang.NullPointerException
10-13 01:28:39.204: E/AndroidRuntime(13862): at com.remote.synchronizer.haris.SQLiteAdapter.getAllContacts(SQLiteAdapter.java:94)
10-13 01:28:39.204: E/AndroidRuntime(13862): at com.remote.synchronizer.haris.OfflineDataService.DataSender(OfflineDataService.java:96)
10-13 01:28:39.204: E/AndroidRuntime(13862): at com.remote.synchronizer.haris.OfflineDataService.access$0(OfflineDataService.java:90)
10-13 01:28:39.204: E/AndroidRuntime(13862): at com.remote.synchronizer.haris.OfflineDataService$1.run(OfflineDataService.java:67)
10-13 01:28:39.204: E/AndroidRuntime(13862): at java.util.Timer$TimerImpl.run(Timer.java:284)
OfflineDataService.java
package com.remote.synchronizer.haris;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import org.apache.http.NameValuePair;
import android.app.IntentService;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;
public class OfflineDataService extends IntentService {
boolean wifi,edge;
private Timer timer= new Timer();
SQLiteDatabase db;
String un,shop,city,date,order;
private SQLiteAdapter mySQLiteAdapter;
Cursor cursor;
public OfflineDataService() {
super("OfflineDataService");
}
@Override
public void onCreate() {
super.onCreate();
Log.e("Service", "Service Created.. ");
mySQLiteAdapter = new SQLiteAdapter(this);
mySQLiteAdapter.getWritableDatabase();
}
@Override
protected void onHandleIntent(Intent intent) {
Bundle bundle=intent.getExtras();
un=bundle.getString("un");
shop=bundle.getString("shop");
city=bundle.getString("city");
date=bundle.getString("date");
order=bundle.getString("order");
Log.e("Service Started", "Successful");
//Inserting New Record
mySQLiteAdapter.insert(un,shop,city,date,order);
timer.scheduleAtFixedRate(new TimerTask(){
@Override
public void run() {
//Checking network connectivity
wifi=NetworkInfo.Wifi(OfflineDataService.this);
edge=NetworkInfo.EDGE(OfflineDataService.this);
if(wifi==true||edge==true)
{
Log.e("Service Network", "Network is online");
DataSender();
}
else
{
Log.e("Service Network", "Network is offline");
}
}
}, 1000, 5000);
}
/*@Override
public void onDestroy() {
super.onDestroy();
// mySQLiteAdapter.deleteAll();
Log.e("Service Destroy", "Successful");
}*/
private void DataSender()
{
//timer.cancel();
List<NameValuePair> contacts=new ArrayList<NameValuePair>();
contacts=mySQLiteAdapter.getAllContacts();
String url="http://10.0.2.2:3325/Product/Create?";
int response = 0;
try
{
response = CustomHttpClient.executeHttpPost(url, contacts);
if(response==200)
{
Log.e("Data Sent", "Response 200");
}
else{
Log.e("Service Data", "Faield to upload data" );
}
}
catch (Exception e)
{
Log.e("Data Sending", e.toString());
e.printStackTrace();
}
}
}
SQLiteAdapter.java
package com.remote.synchronizer.haris;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class SQLiteAdapter extends SQLiteOpenHelper {
public static final String DATABASE_NAME = "Product";
public static final String TABLE_NAME = "Orders";
public static final int DATABASE_VERSION = 1;
public static final String KEY_ID = " _id"; //
public static final String KEY_NAME = "name";
public static final String KEY_SHOP = "shop";
private static final String KEY_CITY = "city";
private static final String KEY_DATE = "datee";
private static final String KEY_ORDER = "orderr";
private static final String CREATE_TABLE =
"CREATE TABLE " + TABLE_NAME + " ("
+ KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ KEY_NAME + " VARCHAR,"
+ KEY_SHOP + " VARCHAR," + KEY_CITY + " VARCHAR, " + KEY_DATE + " VARCHAR, " + KEY_ORDER + " VARCHAR" +");";
public SQLiteAdapter(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(CREATE_TABLE);
}
private SQLiteDatabase sqLiteDatabase;
private SQLiteAdapter sqLiteHelper=this;
public void close(){
sqLiteHelper.close();
}
public void insert(String name, String shop, String city, String datee, String orderr){
try
{
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_NAME, name);
contentValues.put(KEY_SHOP, shop);
contentValues.put(KEY_CITY, city);
contentValues.put(KEY_DATE, datee);
contentValues.put(KEY_ORDER, orderr);
sqLiteDatabase.insertOrThrow(TABLE_NAME, KEY_ID, contentValues);
//sqLiteDatabase.close();
}
catch(Exception e)
{
e.printStackTrace();
Log.e("Insertion", e.toString());
}
}
public void deleteAll(){
sqLiteDatabase.delete(TABLE_NAME, null, null);
}
public void delete_byID(int id){
sqLiteDatabase.delete(TABLE_NAME, KEY_ID+"="+id, null);
}
/*public Cursor queueAll(){
String[] columns = new String[]{KEY_ID, KEY_NAME, KEY_SHOP, KEY_CITY, KEY_DATE, KEY_ORDER};
Cursor cursor = sqLiteDatabase.query(TABLE_NAME, columns,
null, null, null, null, null);
return cursor;
}*/
public List<NameValuePair> getAllContacts() {
List<NameValuePair> postParameters = new ArrayList<NameValuePair>();
String selectQuery = "SELECT * FROM " + TABLE_NAME;
sqLiteHelper.getReadableDatabase();
Cursor cursor = sqLiteDatabase.rawQuery(selectQuery, null);
if(cursor.moveToFirst()){
while(!cursor.isAfterLast())
{
postParameters.add(new BasicNameValuePair("User", cursor.getString(cursor.getColumnIndex(KEY_NAME))));
postParameters.add(new BasicNameValuePair("ShopName", cursor.getString(cursor.getColumnIndex(KEY_SHOP))));
postParameters.add(new BasicNameValuePair("city", cursor.getString(cursor.getColumnIndex(KEY_CITY))));
postParameters.add(new BasicNameValuePair("OrderDate", cursor.getString(cursor.getColumnIndex(KEY_DATE))));
postParameters.add(new BasicNameValuePair("OrderDetail", cursor.getString(cursor.getColumnIndex(KEY_ORDER))));
cursor.moveToNext();
}
}
//cursor.close();
return postParameters;
};
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(SQLiteAdapter.class.getName(),
"Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS " + CREATE_TABLE);
onCreate(db);
}
}
先谢谢
答案 0 :(得分：1)
您永远不会在sqLiteDatabase课程中初始化SQLiteAdapter。
将onCreate方法更改为：
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(CREATE_TABLE);
sqLiteDatabase = db;
}