Android 本地广播空指针异常
我在intentService中有一个本地广播，它向活动发送消息。问题是我得到一个空指针异常。感谢您的帮助：） LogCat错误Android 本地广播空指针异常,android,broadcastreceiver,android-broadcast,localbroadcastmanager,Android,Broadcastreceiver,Android Broadcast,Localbroadcastmanager,我在intentService中有一个本地广播，它向活动发送消息。问题是我得到一个空指针异常。感谢您的帮助：） LogCat错误 01-22 17:57:15.461: I/Arrival(16592): This is instantated 01-22 17:57:16.859: D/sender(16592): Broadcasting message 01-22 17:57:16.867: D/AndroidRuntime(16592): Shutting down VM 01-22 1
01-22 17:57:15.461: I/Arrival(16592): This is instantated
01-22 17:57:16.859: D/sender(16592): Broadcasting message
01-22 17:57:16.867: D/AndroidRuntime(16592): Shutting down VM
01-22 17:57:16.867: W/dalvikvm(16592): threadid=1: thread exiting with uncaught exception (group=0x4110d930)
01-22 17:57:16.875: E/AndroidRuntime(16592): FATAL EXCEPTION: main
01-22 17:57:16.875: E/AndroidRuntime(16592): java.lang.NullPointerException
01-22 17:57:16.875: E/AndroidRuntime(16592): at android.support.v4.content.LocalBroadcastManager.executePendingBroadcasts(LocalBroadcastManager.java:297)
01-22 17:57:16.875: E/AndroidRuntime(16592): at android.support.v4.content.LocalBroadcastManager.access$000(LocalBroadcastManager.java:46)
01-22 17:57:16.875: E/AndroidRuntime(16592): at android.support.v4.content.LocalBroadcastManager$1.handleMessage(LocalBroadcastManager.java:116)
01-22 17:57:16.875: E/AndroidRuntime(16592): at android.os.Handler.dispatchMessage(Handler.java:99)
01-22 17:57:16.875: E/AndroidRuntime(16592): at android.os.Looper.loop(Looper.java:175)
01-22 17:57:16.875: E/AndroidRuntime(16592): at android.app.ActivityThread.main(ActivityThread.java:5279)
01-22 17:57:16.875: E/AndroidRuntime(16592): at java.lang.reflect.Method.invokeNative(Native Method)
01-22 17:57:16.875: E/AndroidRuntime(16592): at java.lang.reflect.Method.invoke(Method.java:511)
01-22 17:57:16.875: E/AndroidRuntime(16592): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
01-22 17:57:16.875: E/AndroidRuntime(16592): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
01-22 17:57:16.875: E/AndroidRuntime(16592): at dalvik.system.NativeStart.main(Native Method)
package.com.user；
公共类到达列表扩展活动{
SqlHandler；
ListView lvCustomList，ListView；
编辑文本图标、总线名称、距离信息；
按钮btnGetData；
MediaPlayer mp；
字符串发送者\u ID=“6159599278”；
静态最终字符串TAG=“GCMDemo”；
谷歌云通讯gcm；
文本视图mDisplay；
语境；
字符串寄存器；
专用广播接收机mMessageReceiver；
ArrayList contactList=新建ArrayList（）；
ContactListAdapter ContactListAdapter=新的ContactListAdapter（此，
联系人名单）；
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.fragment_到达）；
sqlHandler=新的sqlHandler（此）；
btnMap=（按钮）findViewById（R.id.OPEN\u映射）；
RelativeLayout listViewHolder=（RelativeLayout）findViewById（R.id.listViewHolder）；
lvCustomList=newlistview（getApplication（））；
addView（lvCustomList）；
Log.i（“到达”，“这是实例”）；
LocalBroadcastManager.getInstance（this）.registerReceiver（mMessageReceiver，
新的IntentFilter（“自定义事件名称”）；
//我们的接收意图处理程序。每当有意图
//播放名为“自定义事件名称”的操作。
mMessageReceiver=新广播接收器（）{
@凌驾
公共void onReceive（上下文、意图）{
//获取包含在意图中的额外数据
字符串消息=intent.getStringExtra（“消息”）；
Log.i（“接收者”，“收到消息：+消息”）；
}
};
}
@凌驾
受保护的空onDestroy（）{
//取消注册，因为活动即将关闭。
LocalBroadcastManager.getInstance（this）.unregisterReceiver（mMessageReceiver）；
super.ondestory（）；
}
}
公共类获取远程数据扩展IntentService{
SqlHandler；
ListView lvCustomList，ListView；
编辑文本图标、总线名称、距离信息；
按钮btnGetData；
JSONParser JSONParser=新的JSONParser（）；
JSONArray产品=null；
MediaPlayer mp；
字符串发送者\u ID=“6159599278”；
静态最终字符串TAG=“GCMDemo”；
谷歌云通讯gcm；
文本视图mDisplay；
语境；
字符串寄存器；
私有静态字符串URL_距离=”http://vu2150.admin.studentswebprojects.ritaj.ps/Distance_Send_Receive/Get_Distance_From_Database.php";
ArrayList contactList=新建ArrayList（）；
ContactListAdapter ContactListAdapter=新的ContactListAdapter（此，
联系人名单）；
公共获取数据（）{
超级（“获取数据”）；
}
@凌驾
受保护的手部内容无效（意图）{
sqlHandler=新的sqlHandler（此）；
//TODO自动生成的方法存根
字符串registrationId=RegisID（）；
List params=new ArrayList（）；
参数add（新的BasicNameValuePair（“RegistrartionID”，RegistrartionID））；
Log.i（“注册ID”，注册ID）；
JSONObject json=jsonParser.makeHttpRequest（URL_距离，“POST”，
参数）；
String query=“从GPS_信息中删除；”；
executeQuery（查询）；
试一试{
//检查成功标签
int success=json.getInt（“success”）；
如果（成功==1）{
//发现的产品
//获取一系列产品
products=json.getJSONArray（“products”）；
//在所有产品中循环
对于（int i=0；ipackage com.user;
public class Arrival_List extends Activity {
SqlHandler sqlHandler;
ListView lvCustomList, listView;
EditText IconBearing, BusName, DistanceInfo;
Button btnGetData;
MediaPlayer mp;
String SENDER_ID = "616159599278";
static final String TAG = "GCMDemo";
GoogleCloudMessaging gcm;
TextView mDisplay;
Context context;
String regid;
private BroadcastReceiver mMessageReceiver;
ArrayList<ContactListItems> contactList = new ArrayList<ContactListItems>();
ContactListAdapter contactListAdapter = new ContactListAdapter(this,
contactList);
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_arrival);
sqlHandler = new SqlHandler(this);
btnMap = (Button) findViewById(R.id.OPEN_MAP);
RelativeLayout listViewHolder = (RelativeLayout) findViewById(R.id.listViewHolder);
lvCustomList = new ListView(getApplication());
listViewHolder.addView(lvCustomList);
Log.i("Arrival", "This is instantated");
LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,
new IntentFilter("custom-event-name"));
// Our handler for received Intents. This will be called whenever an Intent
// with an action named "custom-event-name" is broadcasted.
mMessageReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
// Get extra data included in the Intent
String message = intent.getStringExtra("message");
Log.i("receiver", "Got message: " + message);
}
};
}
@Override
protected void onDestroy() {
// Unregister since the activity is about to be closed.
LocalBroadcastManager.getInstance(this).unregisterReceiver(mMessageReceiver);
super.onDestroy();
}
}
public class Get_Distane_Data extends IntentService {
SqlHandler sqlHandler;
ListView lvCustomList, listView;
EditText IconBearing, BusName, DistanceInfo;
Button btnGetData;
JSONParser jsonParser = new JSONParser();
JSONArray products = null;
MediaPlayer mp;
String SENDER_ID = "616159599278";
static final String TAG = "GCMDemo";
GoogleCloudMessaging gcm;
TextView mDisplay;
Context context;
String regid;
private static String URL_Distance = "http://vu2150.admin.studentswebprojects.ritaj.ps/Distance_Send_Receive/Get_Distance_From_Database.php";
ArrayList<ContactListItems> contactList = new ArrayList<ContactListItems>();
ContactListAdapter contactListAdapter = new ContactListAdapter(this,
contactList);
public Get_Distane_Data() {
super("Get_Distane_Data");
}
@Override
protected void onHandleIntent(Intent intent) {
sqlHandler = new SqlHandler(this);
// TODO Auto-generated method stub
String RegistrartionID = RegisID();
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("RegistrartionID", RegistrartionID));
Log.i("RegistrartionID", RegistrartionID);
JSONObject json = jsonParser.makeHttpRequest(URL_Distance, "POST",
params);
String query = "DELETE FROM GPS_INFORMATION;";
sqlHandler.executeQuery(query);
try {
// Checking for SUCCESS TAG
int success = json.getInt("success");
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray("products");
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String Bus_Distance = c.getString("Bus_Distance");
String Bus_Bearing = c.getString("Bus_Bearing");
String Bus_Long = c.getString("Bus_Long");
String Bus_Lat = c.getString("Bus_Lat");
String BusName = c.getString("Bus_Name");
Log.i("Bus_Distance", Bus_Distance);
Log.i("Bus_Bearing", Bus_Bearing);
Log.i("Bus_Long", Bus_Long);
Log.i("Bus_Lat", Bus_Lat);
Log.i("BusName", BusName);
try {
String query0 = "INSERT INTO GPS_INFORMATION(Bus_Name,Distance_Info,Icon_Bearing,Bus_Lat,Bus_Long) values ('"
+ Bus_Bearing
+ "','"
+ BusName
+ "','"
+ Bus_Distance
+ "','"
+ Bus_Lat
+ "','"
+ Bus_Long + "')";
sqlHandler.executeQuery(query0);
sendMessage();
} catch (Exception e) {
Log.i("error", "this is where the error happens");
}
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
private void sendMessage() {
Log.d("sender", "Broadcasting message");
Intent intent = new Intent("custom-event-name");
intent.putExtra("message", "This is my message!");
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
}
}
LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,
new IntentFilter("custom-event-name"));