Look at this image and the beautiful amount of errors shown by the bar on the right
我甚至从未触及过Activity.java，它提出了成千上万的异常。我无法筛选所有这些，说实话，我不打算这样做。
有谁能告诉我什么是可能的解决方案？
（如果需要，我会用附加信息编辑这篇文章）
此外，logcat显示以下内容：
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication D/AndroidRuntime:
Shutting down VM
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x41960898)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.denny.myapplication/com.example.denny.myapplication.MainActivity}: java.lang.IllegalStateException: System services not available to Activities before onCreate()
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2219)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2349)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.ActivityThread.access$700(ActivityThread.java:159)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:99)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.os.Looper.loop(Looper.java:137)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5419)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at java.lang.reflect.Method.invokeNative(Native Method)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at java.lang.reflect.Method.invoke(Method.java:525)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1187)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at dalvik.system.NativeStart.main(Native Method)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: Caused by: java.lang.IllegalStateException: System services not available to Activities before onCreate()
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.Activity.getSystemService(Activity.java:4712)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at com.example.denny.myapplication.MainActivity.<init>(MainActivity.java:169)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at java.lang.Class.newInstanceImpl(Native Method)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at java.lang.Class.newInstance(Class.java:1130)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.Instrumentation.newActivity(Instrumentation.java:1078)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2210)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2349)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.ActivityThread.access$700(ActivityThread.java:159)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:99)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.os.Looper.loop(Looper.java:137)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5419)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at java.lang.reflect.Method.invokeNative(Native Method)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at java.lang.reflect.Method.invoke(Method.java:525)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1187)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
10-17 19:40:20.263 7782-7782/com.example.denny.myapplication E/AndroidRuntime: at dalvik.system.NativeStart.main(Native Method)
我的代码：
package com.example.denny.myapplication;
import android.Manifest;
import android.Manifest.permission;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Handler;
import android.provider.Settings;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
PackageManager pm = getPackageManager();
if (pm.checkPermission(permission.ACCESS_FINE_LOCATION, getPackageName()) == PackageManager.PERMISSION_DENIED) {
alertboxGPS();
}
mHandler = new Handler();
startRepeatingTask();
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
}
);
getSystemService(Context.LOCATION_SERVICE);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public PackageManager getPackageManager() {
return super.getPackageManager();
}
@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.
//Also, chuck the subroutine settings here. :3
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
protected void alertboxGPS() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("Your Device's GPS is Disabled")
.setCancelable(true)
.setTitle("** Gps Status **")
.setPositiveButton("Gps On",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// finish the current activity
// AlertBoxAdvance.this.finish();
Intent myIntent = new Intent(
Settings.ACTION_SECURITY_SETTINGS);
startActivity(myIntent);
dialog.cancel();
}
})
.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// cancel the dialog box
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.show();
}
protected void alertboxViolation() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("Please stop walking. You may get in an accident.")
.setCancelable(false)
.setTitle("Walking Warning")
.setPositiveButton("Stop Walking",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// finish the current activity
// AlertBoxAdvance.this.finish();
Intent myIntent = new Intent(
Settings.ACTION_SECURITY_SETTINGS);
startActivity(myIntent);
dialog.cancel();
}
})
.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// cancel the dialog box
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.show();
}
protected void alertboxGranted() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("Access Granted")
.setCancelable(true)
.setTitle("Access to GPS")
.setPositiveButton("Ok",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// finish the current activity
// AlertBoxAdvance.this.finish();
Intent myIntent = new Intent(
Settings.ACTION_SECURITY_SETTINGS);
startActivity(myIntent);
dialog.cancel();
}
})
.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// cancel the dialog box
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.show();
}
//Some Default Integers
int ViolationLimit = 10;
int SpeedLimit = 100;
int ExceedInstance = 0;
//Default Value
LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Location location1 = null;
Location location2 = null;
private double GetSpeed(Location location1, Location location2) {
if (location1 == null) {
location1 = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
location2 = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
} else {
location1 = location2;
}
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)== PackageManager.PERMISSION_GRANTED) {
alertboxGranted();
}
location2 = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
double Distance;
Distance = location1.distanceTo(location2);
double Speed = Distance / mInterval;
return Speed;
}
private int Judge(double Speed, int ViolationLimit, int SpeedLimit, int ExceedInstance) {
if (Speed >= 1 && Speed <= SpeedLimit) {
ExceedInstance += 1;
}
if (ExceedInstance >= ViolationLimit) {
alertboxViolation();
}
return ExceedInstance;
}
void stopRepeatingTask() {
mHandler.removeCallbacks(mStatusChecker);
}
private int mInterval = 3000; // 3 seconds by default, can be changed later
private Handler mHandler;
Runnable mStatusChecker = new Runnable() {
@Override
public void run() {
updateStatus();
mHandler.postDelayed(mStatusChecker, mInterval);
}
};
private void updateStatus() {
//Is used for updating mInterval
}
void startRepeatingTask() {
if (location1 == null && location2 == null) {
double Speed = GetSpeed(location1, location2);
Judge(Speed, ViolationLimit, SpeedLimit, ExceedInstance);
mStatusChecker.run();
}
else {
double Speed = GetSpeed(location1, location2);
Judge(Speed, ViolationLimit, SpeedLimit, ExceedInstance);
mStatusChecker.run();
}
}
}