I am getting the Following error when executing the code

Question

FATAL EXCEPTION: main java.lang.RuntimeException: Unable to start activity ComponentInfo{com.bugs3.munishgupta.cabup/com.bugs3.munishgupta.cabup.WannaHier}: java.lang.NullPointerException at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981) at android.app.ActivityThread.access$600(ActivityThread.java:123) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:4424) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:511) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:825) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:592) at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.NullPointerException at com.bugs3.munishgupta.cabup.WannaHier.onCreate(WannaHier.java:44) at android.app.Activity.performCreate(Activity.java:4465) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1051) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920) ... 11 more

• Wanna Hier.java

          package com.bugs3.munishgupta.cabup;
      import java.util.concurrent.ExecutionException;
      import org.json.JSONArray;
      import org.json.JSONException;
      import org.json.JSONObject;
      import android.app.Activity;
      import android.content.Intent;
      import android.location.Location;
      import android.os.Bundle;
      import android.util.Log;
      import android.view.Menu;
      import android.view.View;
      import android.view.View.OnClickListener;
      import android.widget.Button;
      import android.widget.Toast;
      import com.google.android.gms.maps.GoogleMap;
      import com.google.android.gms.maps.GoogleMap.OnMarkerClickListener;
      import com.google.android.gms.maps.GoogleMap.OnMyLocationChangeListener;
      import com.google.android.gms.maps.MapFragment;
      import com.google.android.gms.maps.model.LatLng;
      import com.google.android.gms.maps.model.Marker;
      import com.google.android.gms.maps.model.MarkerOptions;
  
      public class WannaHier extends Activity {
          GoogleMap map;
          Intent info;
          String mob,lat,lon,title=null;
          Bundle b;
          Button btVCab;
          @Override
          protected void onCreate(Bundle savedInstanceState) {
              super.onCreate(savedInstanceState);
              setContentView(R.layout.wanna_hier);
              info = getIntent();
              b  = info.getExtras();
              mob = b.getString("mob");
              btVCab=(Button) findViewById(R.id.btVCab);
              map=((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
              map.setMyLocationEnabled(true);
              lat=Double.toString(map.getMyLocation().getLatitude());
              lon=Double.toString(map.getMyLocation().getLongitude());
              map.setOnMarkerClickListener(new OnMarkerClickListener() {
  
                  @Override
                  public boolean onMarkerClick(Marker marker) {
                      // TODO Auto-generated method stub
                  try
                  {
                      title=marker.getTitle().toString();
                      request(title,lat,lon,mob);
                  }
                  catch(Exception e)
                  {
                      Toast.makeText(getApplicationContext(), "Please turn on your location", Toast.LENGTH_LONG).show();
                  }
                      return false;
                  }
              });
              map.setOnMyLocationChangeListener(new OnMyLocationChangeListener() {
  
                  @Override
                  public void onMyLocationChange(Location location) {
                      // TODO Auto-generated method stub
                      JSONGetRequest jRequest = JSONGetRequest
                              .getSingleInstance(WannaHier.this);
                      try {
  
                          String url = (Tags.url + "op=update&query=update requestpick set carNo='" +title+
                                "',latitude='" + lat + "', longitude='" + lon +"'where cust_mob='"+ mob +"'").replaceAll(
                                          " ", "%20");
  
                          JSONObject json = jRequest.execute(url).get();
  
                          if (json.getInt("success")==1) {
                              Log.d("Requested Successfully!", json.toString());
                          } else {
                              Log.d("Request failed!", json.getString("message"));
                          }
  
                      } catch (InterruptedException e) {
                          // TODO Auto-generated catch block
                          e.printStackTrace();
                      } catch (ExecutionException e) {
                          // TODO Auto-generated catch block
                          e.printStackTrace();
                      } catch (JSONException e) {
                          // TODO Auto-generated catch block
                          e.printStackTrace();
                      }
                  }
              });
              btVCab.setOnClickListener(new OnClickListener() {
  
                  @Override
                  public void onClick(View v) {
                      // TODO Auto-generated method stub
                      JSONGetRequest jRequest = JSONGetRequest
                              .getSingleInstance(WannaHier.this);
                      try {
  
                          String url = (Tags.url + "op=select&query=select * from driverloc")
                                  .replaceAll(" ", "%20");
  
                          JSONObject json = jRequest.execute(url).get();
  
                          if (json.getInt("success")==1) {
                              Log.d("Requested Successfully!", json.toString());
                              JSONArray js=json.getJSONArray("entities");
                              try{
                                  for(int co=js.length(), i=0; i<co;i++){
                                      json=js.getJSONObject(i);
                                      title=json.getString("carNo");
                                      lat=json.getString("latitude");
                                      lon=json.getString("longitude");
                                      map.addMarker(new MarkerOptions()
                                      .position(new LatLng(Double.parseDouble(lat),Double.parseDouble(lon)))
                                      .title(title));
                                  }
                              }
                              catch(JSONException e) {
                                  e.printStackTrace();
                              }           
                          } else {
                              Log.d("Request failed!", json.getString("message"));
                          }
  
                      } catch (InterruptedException e) {
                          // TODO Auto-generated catch block
                          e.printStackTrace();
                      } catch (ExecutionException e) {
                          // TODO Auto-generated catch block
                          e.printStackTrace();
                      } catch (JSONException e) {
                          // TODO Auto-generated catch block
                          e.printStackTrace();
                      }
  
                  }
              });
          }
          @Override
          protected void onStart() {
              // TODO Auto-generated method stub
              super.onStart();
              Toast.makeText(getApplicationContext(), "Please Turn on your location and click on view cabs", Toast.LENGTH_LONG).show();
          }
  
          public void request(String title, String lat, String lon, String mob )
          {
              JSONGetRequest jRequest = JSONGetRequest
                      .getSingleInstance(WannaHier.this);
              try {
  
                  String url = (Tags.url + "op=insert&query=insert into requestpick values ('"
                          +title+ "','" + lat + "','" + lon +"','"+ mob +"')").replaceAll(
                                  " ", "%20");
  
                  JSONObject json = jRequest.execute(url).get();
  
                  if (json.getInt("success")==1) {
                      Log.d("Requested Successfully!", json.toString());
                  } else {
                      Log.d("Request failed!", json.getString("message"));
                  }
  
              } catch (InterruptedException e) {
                  // TODO Auto-generated catch block
                  e.printStackTrace();
              } catch (ExecutionException e) {
                  // TODO Auto-generated catch block
                  e.printStackTrace();
              } catch (JSONException e) {
                  // TODO Auto-generated catch block
                  e.printStackTrace();
              }
          }
          @Override
          protected void onPause() {
              // TODO Auto-generated method stub
              super.onPause();
              JSONGetRequest jRequest = JSONGetRequest
                      .getSingleInstance(WannaHier.this);
              try {
  
                  String url = (Tags.url + "op=delete&query=delete from requestpick where cust_mob='"
                  + mob +"'").replaceAll(" ", "%20");
  
                  JSONObject json = jRequest.execute(url).get();
  
                  if (json.getInt("success")==1) {
                      Log.d("Requested Successfully!", json.toString());
                  } else {
                      Log.d("Request failed!", json.getString("message"));
                  }
  
              } catch (InterruptedException e) {
                  // TODO Auto-generated catch block
                  e.printStackTrace();
              } catch (ExecutionException e) {
                  // TODO Auto-generated catch block
                  e.printStackTrace();
              } catch (JSONException e) {
                  // TODO Auto-generated catch block
                  e.printStackTrace();
              }
  
              finish();
          }
          @Override
          public boolean onCreateOptionsMenu(Menu menu) {
              // Inflate the menu; this adds items to the action bar if it is present.
              getMenuInflater().inflate(R.menu.wanna_hier, menu);
              return true;
          }
  
      }
  

• Profile.java

  package com.bugs3.munishgupta.cabup;
  import com.bugs3.munishgupta.cabup.R;
  import android.app.Activity;
  import android.content.Intent;
  import android.os.Bundle;
  import android.view.Menu;
  import android.view.View;
  import android.view.View.OnClickListener;
  import android.widget.Button;
  import android.widget.Toast;
  
  public class Profile extends Activity {
  
  Button obhier, obshare, obsettings;
  String mob,carno,table;
  Intent info;
  Bundle b;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.profile);
      obhier=(Button) findViewById(R.id.btnHier);
      obshare=(Button) findViewById(R.id.btnShare);
      obsettings=(Button) findViewById(R.id.btnSetting);
      info = getIntent();
      b  = info.getExtras();
      table=b.getString("table");
  
      if((carno=b.getString("carno"))!=null )
      {
          Toast.makeText(getApplicationContext(), carno, Toast.LENGTH_SHORT).show();
          obhier.setVisibility(View.INVISIBLE);       
      }
      else
      {
          obshare.setVisibility(View.INVISIBLE);
      }
  
      obshare.setOnClickListener(new OnClickListener() {
  
          @Override
          public void onClick(View v) {
              // TODO Auto-generated method stub
              Intent wshare=new Intent(Profile.this,WannaShare.class);
                  mob = b.getString("mob");
                  wshare.putExtra("mob", mob);
                  wshare.putExtra("carno", carno);
                  wshare.putExtra("table", table);
                  startActivity(wshare);
          }
      });
      obhier.setOnClickListener(new OnClickListener() {
  
          @Override
          public void onClick(View v) {
              // TODO Auto-generated method stub
              Intent whier=new Intent(Profile.this,WannaHier.class);
                  mob = b.getString("mob");
                  whier.putExtra("mob", mob);
                  whier.putExtra("table", table);
                  startActivity(whier);
          }
      });
      obsettings.setOnClickListener(new OnClickListener() {
  
          @Override
          public void onClick(View v) {
              // TODO Auto-generated method stub
              Intent isetting = new Intent(Profile.this,ChangeSetting.class);
              if(b.getString("mob")!=null)
              {
                  mob = b.get("mob").toString();
                  isetting.putExtra("mob", mob);
                  isetting.putExtra("table", table);
              }
              startActivity(isetting);
          }      
      });       
  }
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {        
      // Inflate the menu; this adds items to the action bar if it is present.
      getMenuInflater().inflate(R.menu.profile, menu);
      return true;
  }
  }
  

Answer 1

The answer is at WannaHier: line 44 which I suspect it to be

lat=Double.toString(map.getMyLocation().getLatitude());

Because getMyLocation() can return null if there is no location available so you have to check for this.

For example:

Location location = map.getMyLocation();
if(location != null){
    lat=Double.toString(location.getLatitude());
    lon=Double.toString(location.getLongitude()); 
}