nicht in der Lage, einen Dienst Fehler in Android

Question

zu starten Ich habe einen Dienst in meiner Anwendung erstellt und die Funktion aufgerufen, die den Dienst mithilfe einer Schaltfläche mit OnClick in XML gestartet, aber die App abstürzt. einige Hilfe wird geschätzt. Paket slide.apptech.com.nav;

import android.app.AlarmManager; 
import android.app.PendingIntent; 
import android.app.ProgressDialog; 
import android.content.Context; 
import android.content.Intent; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.os.StrictMode; 
import android.support.annotation.Nullable; 
import android.view.View; 
import android.support.design.widget.NavigationView; 
import android.support.v4.view.GravityCompat; 
import android.support.v4.widget.DrawerLayout; 
import android.support.v7.app.ActionBarDrawerToggle; 
import android.support.v7.app.AppCompatActivity; 
import android.support.v7.widget.Toolbar; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.widget.Button; 
import android.widget.ListView; 
import android.widget.TextView; 
import android.widget.Toast; 
import android.support.design.widget.FloatingActionButton; 

import java.util.ArrayList; 
import java.util.Calendar; 

import static java.util.Calendar.*; 

public class MainActivity extends AppCompatActivity 
    implements NavigationView.OnNavigationItemSelectedListener { 

private static String TAG = MainActivity.class.getSimpleName(); 
private Intent myIntent; 
Button Refresh; 
TextView updated; 

//related to main screen list view 
ListView lv; 
Context context; 
ArrayList prgmName; 
public static int [] prgmImages={R.drawable.temp,R.drawable.hum,R.drawable.press,R.drawable.amb,R.drawable.alt}; 
public static String [] prgmNameList={" Temperature: "," Humidity: "," Pressure: "," Ambient Light:"," Altitude: "}; 
//GetFromServer gs1=new GetFromServer(); 
public String [] prgmVal={"1","2","3","4","5"}; 
public static String [] prgmUnit={" °C"," %"," hPa"," lx"," m"}; 
//public String datentime=gs1.DateNTime[0]; 
String datentime; 

//boolean variable to indicate if the arrays have been set or not 
Boolean arraysset; 
GetFromServer gs1; 
public ArrayList<String> atList=new ArrayList<String>(); 
public ArrayList<String> dataList=new ArrayList<String>(); 


@Override 
protected void onCreate(Bundle savedInstanceState) { 

    //these lines overite all the warnings by android to restrict large tasks 
    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build(); 
    StrictMode.setThreadPolicy(policy); 

    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 

    lv = (ListView) findViewById(R.id.listView); 
    updated=(TextView)findViewById((R.id.datentime)); 
    Refresh = (Button) findViewById(R.id.refresh); 

    //block related to main screen list view 
    //creating a object from getfromserver class to give a request to server 
    gs1=new GetFromServer(); 
    new loadSomeStuff().execute(); 
    updated.setText(datentime); 

    prgmVal[0]=Double.toString(gs1.Temperature[0]); 
    prgmVal[1]=Double.toString(gs1.Humidity[0]); 
    prgmVal[2]=Double.toString(gs1.Pressure[0]); 
    prgmVal[3]=Double.toString(gs1.Ambient[0]); 
    prgmVal[4]=Double.toString(gs1.Altitude[0]); 
    datentime="Updated on :"+gs1.DateNTime[0]; 
    context = this; 

    //this adapter is defined in custom adapter 
    // see class for all the constructors 
    lv.setAdapter(new CustomAdapter(MainActivity.this, MainActivity.prgmNameList, MainActivity.prgmImages, prgmVal, MainActivity.prgmUnit)); 

    //code related to refresh button the main screen find xml in content_main 
    Refresh.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 

      startService(new Intent(getBaseContext(),service.class)); 
      //Toast.makeText(context, "Please wait!", Toast.LENGTH_LONG).show(); 
      gs1 = new GetFromServer(); 
      gs1.sendData(); 
      gs1.setArray(); 

      //codeline to start athe service 


      prgmVal[0] = Double.toString(gs1.Temperature[0]); 
      prgmVal[1] = Double.toString(gs1.Humidity[0]); 
      prgmVal[2] = Double.toString(gs1.Pressure[0]); 
      prgmVal[3] = Double.toString(gs1.Ambient[0]); 
      prgmVal[4] = Double.toString(gs1.Altitude[0]); 
      String datentime = "Updated on :" + gs1.DateNTime[0]; 
      updated.setText(datentime); 
      context = MainActivity.this; 
      lv.setAdapter(new CustomAdapter(MainActivity.this, MainActivity.prgmNameList, MainActivity.prgmImages, prgmVal, MainActivity.prgmUnit)); 
      //Toast.makeText(context, "Refreshed!!!", Toast.LENGTH_LONG).show(); 
     } 
    }); 


    //this code is for a floation button see xml 

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
    fab.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Intent myIntent = new Intent(MainActivity.this,Faq.class); 
      startActivity(myIntent); 
     } 
    }); 

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
      this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close); 
    drawer.setDrawerListener(toggle); 
    toggle.syncState(); 

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view); 
    navigationView.setNavigationItemSelectedListener(this); 
} 

//this is code related to back button in action bar to close drawer if open else go back to previous activity 
@Override 
public void onBackPressed() { 
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
    if (drawer.isDrawerOpen(GravityCompat.START)) { 
     drawer.closeDrawer(GravityCompat.START); 
    } else { 
     super.onBackPressed(); 
    } 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 

    //noinspection SimplifiableIfStatement 
    if (id == R.id.action_settings) { 
     return true; 
    } 

    return super.onOptionsItemSelected(item); 
} 

//app crash due to following code 
@SuppressWarnings("StatementWithEmptyBody") 
@Override 
public boolean onNavigationItemSelected(MenuItem item) { 
    // Handle navigation view item clicks here. 
    int id = item.getItemId(); 

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
    if (id == R.id.liConnection) { 
     drawer.closeDrawer(GravityCompat.START); 
     Intent myIntent = new Intent(MainActivity.this, Connect.class); 
     startActivity(myIntent); 
    } 
    else if (id == R.id.liRanges){ 
     drawer.closeDrawer(GravityCompat.START); 
     Intent myIntent = new Intent(MainActivity.this, Ranges.class); 
     startActivity(myIntent); 
    } 
    else if (id == R.id.liSupport) { 
     drawer.closeDrawer(GravityCompat.START); 
     Intent myIntent = new Intent(MainActivity.this, Support.class); 
     startActivity(myIntent); 
    } 
    else if (id == R.id.liAbout) { 
     drawer.closeDrawer(GravityCompat.START); 
     Intent myIntent = new Intent(MainActivity.this, AboutUs.class); 
     startActivity(myIntent); 
    } 
    else if (id == R.id.liRateus) { 
     drawer.closeDrawer(GravityCompat.START); 
     Intent myIntent = new Intent(MainActivity.this,Rateus.class); 
     startActivity(myIntent); 
    } 
    return true; 
} 


public void getPosition(int position) { 
    if (position == 0) { 
     //code specific to first list item 
     myIntent = new Intent(MainActivity.this, ChartTemperature.class); //replace connect classs with analysis 
     startActivity(myIntent); 
    } 
    else if (position == 1) { 
     //code specific to first list item 
     Intent myIntent = new Intent(MainActivity.this, ChartHumidity.class); 
     startActivity(myIntent); 
    } 
    else if (position == 2) { 
     //code specific to first list item 
     Intent myIntent = new Intent(MainActivity.this, ChartPressure.class); 
     startActivity(myIntent); 
    } 
    else if (position == 3) { 
     //code specific to first list item 
     Intent myIntent = new Intent(MainActivity.this, ChartAmbient.class); 
     startActivity(myIntent); 
    } 
    else if (position == 4) { 
     //code specific to first list item 
     Intent myIntent = new Intent(MainActivity.this, ChartAltitude.class); 
     startActivity(myIntent); 
    } 
} 

// Method to start the service 
public void startService(View view) { 
    startService(new Intent(getBaseContext(), service.class)); 
} 

//here we are creating a async task to reduce load on oncreate method 
public class loadSomeStuff extends AsyncTask<String, Integer, Void> { 

    @Override 
    protected Void doInBackground(String... params) { 
     // TODO Auto-generated method stub 


      try { 
       gs1.sendData(); 
       gs1.setArray(); 
       prgmVal[0]=Double.toString(gs1.Temperature[0]); 
       prgmVal[1]=Double.toString(gs1.Humidity[0]); 
       prgmVal[2]=Double.toString(gs1.Pressure[0]); 
       prgmVal[3]=Double.toString(gs1.Ambient[0]); 
       prgmVal[4]=Double.toString(gs1.Altitude[0]); 
       datentime="Updated on :"+gs1.DateNTime[0]; 

       arraysset = true; 
      } catch (Exception e) { 
       e.printStackTrace(); 
      } 
     return null; 
    } 
} 

}

service.java

package slide.apptech.com.nav; 

import android.app.Notification; 
import android.app.NotificationManager; 
import android.app.Service; 
import android.content.Context; 
import android.content.Intent; 
import android.os.IBinder; 
import android.support.annotation.Nullable; 
import android.widget.Toast; 

/** 
* Created by MOHIT on 17-04-2016. 
*/ 
public class service extends Service{ 
    //creating a server class object 
    GetFromServer gs1; 

    //creating a database object 
    database record; 
    String value; 
    boolean tempflag,pressflag,humflag,lightflag; 
    double temperature,humidity,pressure,light,max,min; 
    NotificationManager manager; 
    Notification myNotication; 
    Context context; 
    MainActivity main; 
    public final String UPDATE_DATA = "update"; 

    @Override 
    public int onStartCommand(Intent intent, int flags, int startId) { 
     //Toast.makeText(context, "Service Started in onStartCommand", Toast.LENGTH_LONG).show(); 
     if(intent.getAction().equals(UPDATE_DATA)){ 
      Toast.makeText(context, "Service Started in onStartCommand", Toast.LENGTH_LONG).show(); 
      //getandcheck(); 
     } 
     return START_STICKY; 
    } 

    @Nullable 
    @Override 
    public IBinder onBind(Intent intent) { 
     return null; 
    } 

    public void getandcheck(){ 

     //getting the values from server 
     gs1 = new GetFromServer(); 
     gs1.sendData(); 
     gs1.setArray(); 
     //setting variables to latest sensor values 
     temperature = gs1.Temperature[0]; 
     humidity = gs1.Humidity[0]; 
     pressure = gs1.Pressure[0]; 
     light = gs1.Ambient[0]; 

     record.open(); 

     //making function calls to setup flags 
     checktemp(); 
     checkhum(); 
     checkpress(); 
     checklight(); 

     //if any flag is true the it means that readings are out of range 
     if(tempflag == true){ 

      String readings = ("Temperature : " + temperature +" °C"); 


      final Notification.Builder builder = new Notification.Builder(service.this); 
      builder.setStyle(new Notification.BigTextStyle(builder) 
        .bigText(readings) 
        .setBigContentTitle("WSstation") 
        .setSummaryText("Alert!!!")) 
        .setContentTitle("WSstation") 
        .setContentText("Your Temperature Readings are out of range") 
        .setSmallIcon(R.drawable.auicon); 

      final NotificationManager nm = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE); 
      nm.notify(0, builder.build()); 
     } 

     if(pressflag == true){ 

      String readings = ("Pressure : " + pressure +" hpa"); 


      final Notification.Builder builder = new Notification.Builder(service.this); 
      builder.setStyle(new Notification.BigTextStyle(builder) 
        .bigText(readings) 
        .setBigContentTitle("WSstation") 
        .setSummaryText("Alert!!!")) 
        .setContentTitle("WSstation") 
        .setContentText("Your Pressure Readings are out of range") 
        .setSmallIcon(R.drawable.auicon); 

      final NotificationManager nm = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE); 
      nm.notify(0, builder.build()); 
     } 

     if(humflag == true){ 

      String readings = ("Humidity : " + humidity +" %"); 


      final Notification.Builder builder = new Notification.Builder(service.this); 
      builder.setStyle(new Notification.BigTextStyle(builder) 
        .bigText(readings) 
        .setBigContentTitle("WSstation") 
        .setSummaryText("Alert!!!")) 
        .setContentTitle("WSstation") 
        .setContentText("Your Humidity Readings are out of range") 
        .setSmallIcon(R.drawable.auicon); 

      final NotificationManager nm = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE); 
      nm.notify(0, builder.build()); 
     } 

     if(lightflag == true){ 

      String readings = ("Ambient Light : " + light +" lx"); 


      final Notification.Builder builder = new Notification.Builder(service.this); 
      builder.setStyle(new Notification.BigTextStyle(builder) 
        .bigText(readings) 
        .setBigContentTitle("WSstation") 
        .setSummaryText("Alert!!!")) 
        .setContentTitle("WSstation") 
        .setContentText("Your Ambient Light Readings are out of range") 
        .setSmallIcon(R.drawable.auicon); 

      final NotificationManager nm = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE); 
      nm.notify(0, builder.build()); 
     } 
    } 

    public void checktemp(){ 
     //for temperature checking 
     value = record.getMax(1); 
     max = Double.parseDouble(value); 
     value = record.getMin(1); 
     min = Double.parseDouble(value); 

     if((temperature < min) || (temperature > max)){ 
      tempflag = true; 
     } 
     else{ 
      tempflag = false; 
     } 
    } 

    public void checkhum(){ 
     //for humidity checking 
     value = record.getMax(3); 
     max = Double.parseDouble(value); 
     value = record.getMin(3); 
     min = Double.parseDouble(value); 

     if((humidity < min) || (humidity > max)){ 
      humflag = true; 
     } 
     else{ 
      humflag = false; 
     } 
    } 

    public void checkpress(){ 
     //for pressure checking 
     value = record.getMax(2); 
     max = Double.parseDouble(value); 
     value = record.getMin(2); 
     min = Double.parseDouble(value); 

     if((pressure < min) || (pressure > max)){ 
      pressflag = true; 
     } 
     else{ 
      pressflag = false; 
     } 
    } 

    public void checklight(){ 
     //for ambient light checking 
     value = record.getMax(4); 
     max = Double.parseDouble(value); 
     value = record.getMin(4); 
     min = Double.parseDouble(value); 

     if((light < min) || (light > max)){ 
      lightflag = true; 
     } 
     else{ 
      lightflag = false; 
     } 
    } 

    /*@Override 
    public void onCreate() { 
     super.onCreate(); 
     Toast.makeText(context, "Service Started in oncreate", Toast.LENGTH_LONG).show(); 
    }*/ 

} 

content_main.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    app:layout_behavior="@string/appbar_scrolling_view_behavior" 
    tools:context="slide.apptech.com.nav.MainActivity" 
    tools:showIn="@layout/app_bar_main"> 

    <RelativeLayout 
     android:id="@+id/mainContent" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:background="#004D40"> 



     <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
      xmlns:tools="http://schemas.android.com/tools" 
      android:background="#004D40" 
      android:layout_width="match_parent" 
      android:layout_height="fill_parent" 
      android:orientation="vertical" 
      android:paddingBottom="@dimen/activity_vertical_margin" 
      android:paddingLeft="@dimen/activity_horizontal_margin" 
      android:paddingRight="@dimen/activity_horizontal_margin" 
      android:paddingTop="@dimen/activity_vertical_margin" 
      tools:context=".Home" 
      android:layout_alignParentTop="true" 
      android:layout_alignParentStart="true"> 

      <!--<TextView 
       android:id="@+id/textView1" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:textSize="25dp" 
       android:textStyle="bold" 
       android:text=" Computer Languages..." /> 
       --> 

      <ListView 
       android:paddingTop="60dp" 
       android:id="@+id/listView" 
       android:layout_width="fill_parent" 
       android:layout_height="376dp" 
       android:layout_above="@+id/datentime"> 
      </ListView> 

      <TextView 
       android:paddingTop="20dp" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:textAppearance="?android:attr/textAppearanceSmall" 
       android:text="Updated:" 
       android:textColor="#FFEB3B" 
       android:id="@+id/datentime" 
       android:layout_gravity="center_horizontal" /> 

      <Button 
       style="?android:attr/buttonStyleSmall" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:text="Refresh" 
       android:id="@+id/refresh" 
       android:layout_gravity="center_horizontal" 
       android:onClick="startService"/> 


     </LinearLayout> 

    </RelativeLayout> 

</RelativeLayout> 

logcat

04-20 20:15:18.623 27500-27500/slide.apptech.com.nav E/MotionRecognitionManager: mSContextService = null 
04-20 20:15:18.628 27500-27500/slide.apptech.com.nav E/MotionRecognitionManager: motionService = com.samsung.android.motion.IMotionRecognitionService$Stub$Proxy@28c858d 
04-20 20:15:24.578 27500-27500/slide.apptech.com.nav E/AndroidRuntime: FATAL EXCEPTION: main 
                     Process: slide.apptech.com.nav, PID: 27500 
                     java.lang.RuntimeException: Unable to start service slide.apptech.com.nav.service@1aa1fa82 with Intent { cmp=slide.apptech.com.nav/.service }: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference 
                      at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3978) 
                      at android.app.ActivityThread.access$2300(ActivityThread.java:211) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1803) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:145) 
                      at android.app.ActivityThread.main(ActivityThread.java:6912) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at java.lang.reflect.Method.invoke(Method.java:372) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199) 
                     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference 
                      at slide.apptech.com.nav.service.onStartCommand(service.java:33) 
                      at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3961) 
                      at android.app.ActivityThread.access$2300(ActivityThread.java:211)  
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1803)  
                      at android.os.Handler.dispatchMessage(Handler.java:102)  
                      at android.os.Looper.loop(Looper.java:145)  
                      at android.app.ActivityThread.main(ActivityThread.java:6912)  
                      at java.lang.reflect.Method.invoke(Native Method)  
                      at java.lang.reflect.Method.invoke(Method.java:372)  
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)  
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)  

Answer 1

Die Absicht, die Sie einchecken service.onStartCommand hat keine Aktion. Ändern Sie diese

if(intent.getAction().equals(UPDATE_DATA)){ 
    Toast.makeText(context, "Service Started in onStartCommand", Toast.LENGTH_LONG).show(); 
    //getandcheck(); 
} 

in diesem

if(intent.getAction() != null && intent.getAction().equals(UPDATE_DATA)){ 
    Toast.makeText(context, "Service Started in onStartCommand", Toast.LENGTH_LONG).show(); 
    //getandcheck(); 
} 

UPDATE
Um noch den Toast zeigen Sie könnte einen zusätzlichen boolean in Ihrer Absicht setzen und prüfen, ob diese in Ihren Diensten. Beginnen Sie Ihren Dienst wie diese

startService(new Intent(getBaseContext(),service.class).putExtra("show_toast", true)); 

und prüfen, ob es in Ihrem Dienst wie diese

if (intent.getBooleanExtra("show_toast", false)) { 
    Toast.makeText(context, "Service Started in onStartCommand", Toast.LENGTH_LONG).show(); 
    //getandcheck(); 
} 

Answer 2

Sehen aus wie Sie nicht eine Aktion für die Absicht angegeben haben und Sie einen Null-Zeiger immer aus diesem Grunde . Stellen Sie außerdem sicher, dass Sie die String-Konstante für den Objektwert überprüfen, um Nullzeigerausnahmen zu vermeiden.