我创建了一个项目，该项目使用一个名为service class的类来连续获取位置并将其保存到数组列表中。但它显示出一些错误。该项目是在Android 2.1
Serviceclass.java
package com.example.tracemeendpointsjson;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import Trace.date.TimeDate;
import android.app.Service;
import android.content.Intent;
import android.location.Address;
import android.location.Criteria;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.util.Log;
import android.widget.Toast;
public class ServiceClass extends Service implements LocationListener {
double mLongitude ;
double mLatitude;
boolean check;
public static int k;
CommonClass cmn;
MainActivity ma;
int i;
LocationManager mLocationManager;
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onCreate() {
super.onCreate();
Toast.makeText(ServiceClass.this, "Service started", Toast.LENGTH_SHORT).show();
cmn=new CommonClass();
ma=new MainActivity();
cmn.StartTime=new TimeDate().timeToString();
System.out.println("StartTime :: "+cmn.StartTime);
cmn.StartDate=new TimeDate().dateToString();
System.out.println("StartDate :: "+cmn.StartDate);
check = true;
i = 0;
k=0;
initializeLocationAndStartGpsThread();
}
@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
setCurrentGpsLocation(location);
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
private void setCurrentGpsLocation(Location location) {
String bestProvider = "";
if (location == null) {
mLocationManager =(LocationManager) getSystemService(LOCATION_SERVICE);
mLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 1000, 0, this); // Every 10000 msecs
System.out.println("GPS_PROVIDER: ");
location = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
}
try {
mLongitude = location.getLongitude();
mLatitude = location.getLatitude();
String la=Double.toString(mLatitude);
String ln=Double.toString(mLongitude);
System.out.println("B 4 Size :: "+cmn.Lat.size());
System.out.println("B 4 array :: "+cmn.Lat);
cmn.Lat.add(la);
cmn.Long.add(ln);
System.out.println("after size :: "+cmn.Lat.size());
System.out.println("after array :: "+cmn.Lat);
String UpdatedTime=new TimeDate().timeToString();
cmn.TimeArray.add(UpdatedTime);
System.out.println("UpdatedTime :: "+UpdatedTime);
System.out.println("cmn.TimeArray :: "+cmn.TimeArray.size());
System.out.println("cmn.TimeArray :: "+cmn.TimeArray);
String UpdatedDate=new TimeDate().dateToString();
cmn.DateArray.add(UpdatedDate);
System.out.println("UpdatedDate :: "+UpdatedDate);
System.out.println("cmn.DateArray :: "+cmn.DateArray.size());
System.out.println("cmn.DateArray :: "+cmn.DateArray);
k++;
// Log.i("hai01", "<long,lat> = <" + mLongitude + "," + mLatitude);
// System.out.println("LOgGgggggggggggg");
Message msg = Message.obtain();
msg.what = 1;
ServiceClass.this.updateHandler.sendMessage(msg);
String cityName = null;
Geocoder gcd = new Geocoder(ServiceClass.this, Locale.ENGLISH);
List<Address> addresses=null;
try {
addresses = gcd.getFromLocation(mLongitude, mLatitude, 1);
if (addresses.size() > 0)
System.out.println(addresses.get(0).getLocality());
cityName = addresses.get(0).getLocality();
} catch (IOException e) {
e.printStackTrace();
}
String s = ln + "\n" + la
+ "\n\nMy Current City is: " + cityName;
Toast.makeText(ServiceClass.this, "City is:"+s, Toast.LENGTH_SHORT).show();
} catch (NullPointerException e) {
Log.i("hai02", "Null pointer exception ");
}
}
Handler updateHandler = new Handler() {
/** Gets called on every message that is received */
// @Override
public void handleMessage(Message msg) {
switch (msg.what) {
case 1: {
Log.i("hai03", "Updated location = " + mLatitude + " " + mLongitude);
break;
}
case 0: {
Log.i("hai000000000000", "Running");
break;
}
}
super.handleMessage(msg);
}
};
private void initializeLocationAndStartGpsThread() {
mLocationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
List<String> providers = mLocationManager.getProviders(true);
Log.i("hai04", "Enabled providers = " + providers.toString());
String provider = mLocationManager.getBestProvider(new Criteria(),true);
Log.i("hai05", "Best provider = " + provider);
//setCurrentGpsLocation(null);
}
@Override
public void onDestroy() {
super.onDestroy();
check = false;
i = 0;
cmn.Lat.clear();
cmn.Long.clear();
cmn.FinalDistance.clear();
ma.finaldist=0.0f;
cmn.TimeArray.clear();
cmn.DateArray.clear();
System.out.println("Clear size :: "+cmn.Lat);
System.out.println("Clear size :: "+cmn.Long);
System.out.println("Clear size :: "+cmn.Lat.size());
System.out.println("Clear size :: "+cmn.Long.size());
Toast.makeText(ServiceClass.this, "Service stopped", Toast.LENGTH_SHORT)
.show();
}
}
Logcat输出是：
04-10 22:55:50.318: E/AndroidRuntime(249): Uncaught handler: thread main exiting due to uncaught exception
04-10 22:55:50.361: E/AndroidRuntime(249): java.lang.RuntimeException: Unable to create service com.example.tracemeendpointsjson.ServiceClass: java.lang.IndexOutOfBoundsException: Invalid location 0, size is 0
04-10 22:55:50.361: E/AndroidRuntime(249): at android.app.ActivityThread.handleCreateService(ActivityThread.java:2790)
04-10 22:55:50.361: E/AndroidRuntime(249): at android.app.ActivityThread.access$3200(ActivityThread.java:119)
04-10 22:55:50.361: E/AndroidRuntime(249): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1917)
04-10 22:55:50.361: E/AndroidRuntime(249): at android.os.Handler.dispatchMessage(Handler.java:99)
04-10 22:55:50.361: E/AndroidRuntime(249): at android.os.Looper.loop(Looper.java:123)
04-10 22:55:50.361: E/AndroidRuntime(249): at android.app.ActivityThread.main(ActivityThread.java:4363)
04-10 22:55:50.361: E/AndroidRuntime(249): at java.lang.reflect.Method.invokeNative(Native Method)
04-10 22:55:50.361: E/AndroidRuntime(249): at java.lang.reflect.Method.invoke(Method.java:521)
04-10 22:55:50.361: E/AndroidRuntime(249): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
04-10 22:55:50.361: E/AndroidRuntime(249): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
04-10 22:55:50.361: E/AndroidRuntime(249): at dalvik.system.NativeStart.main(Native Method)
04-10 22:55:50.361: E/AndroidRuntime(249): Caused by: java.lang.IndexOutOfBoundsException: Invalid location 0, size is 0
04-10 22:55:50.361: E/AndroidRuntime(249): at java.util.ArrayList.get(ArrayList.java:341)
04-10 22:55:50.361: E/AndroidRuntime(249): at com.example.tracemeendpointsjson.ServiceClass.setCurrentGpsLocation(ServiceClass.java:143)
04-10 22:55:50.361: E/AndroidRuntime(249): at com.example.tracemeendpointsjson.ServiceClass.initializeLocationAndStartGpsThread(ServiceClass.java:193)
04-10 22:55:50.361: E/AndroidRuntime(249): at com.example.tracemeendpointsjson.ServiceClass.onCreate(ServiceClass.java:55)
04-10 22:55:50.361: E/AndroidRuntime(249): at android.app.ActivityThread.handleCreateService(ActivityThread.java:2780)
请帮帮我
答案 0 :(得分：0)
这是你的罪魁祸首：
04-10 22:55:50.361: E/AndroidRuntime(249): Caused by: java.lang.IndexOutOfBoundsException: Invalid location 0, size is 0
04-10 22:55:50.361: E/AndroidRuntime(249): at com.example.tracemeendpointsjson.ServiceClass.setCurrentGpsLocation(ServiceClass.java:143)
在ServiceClass.java第143行中，您将超出数组的范围，因此导致应用程序崩溃的异常。这就是因为你养成了不把条件块放在括号中的坏习惯，所以你有
if (addresses.size() > 0)
System.out.println(addresses.get(0).getLocality());
cityName = addresses.get(0).getLocality();
你应该
if (addresses.size() > 0) {
System.out.println(addresses.get(0).getLocality());
cityName = addresses.get(0).getLocality();
}