致命的例外：主要 java.lang.RuntimeException：无法启动活动ComponentInfo {com.bugs3.munishgupta.cabup / com.bugs3.munishgupta.cabup.WannaHier}：java.lang.NullPointerException 在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:1956） 在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:1981） 在android.app.ActivityThread.access $ 600（ActivityThread.java:123） 在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1147） 在android.os.Handler.dispatchMessage（Handler.java:99） 在android.os.Looper.loop（Looper.java:137） 在android.app.ActivityThread.main（ActivityThread.java:4424） at java.lang.reflect.Method.invokeNative（Native Method） 在java.lang.reflect.Method.invoke（Method.java:511） 在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:825） 在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:592） at dalvik.system.NativeStart.main（Native Method） 引起：java.lang.NullPointerException 在com.bugs3.munishgupta.cabup.WannaHier.onCreate（WannaHier.java:44） 在android.app.Activity.performCreate（Activity.java:4465） 在android.app.Instrumentation.callActivityOnCreate（Instrumentation.java:1051） 在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:1920） ......还有11个
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;
}
}
答案 0 :(得分：0)
答案是WannaHier: line 44
我怀疑它是
lat=Double.toString(map.getMyLocation().getLatitude());
如果没有可用的位置，getMyLocation()可以返回null，因此您必须检查此内容。
例如：
Location location = map.getMyLocation();
if(location != null){
lat=Double.toString(location.getLatitude());
lon=Double.toString(location.getLongitude());
}