对于很多用户，我遇到了以下崩溃：
Fatal Exception: java.lang.NullPointerException: Attempt to invoke interface method 'java.util.Set java.util.Map.keySet()' on a null object reference
at com.google.android.gms.internal.zzbtn.zza(Unknown Source)
at com.google.android.gms.internal.zzbtn.run(Unknown Source)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
我通过外部库搜索，发现崩溃的来源是以下类zzbtn中的firebase-config库（参见方法-zza（））。
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package com.google.android.gms.internal;
import android.content.Context;
import android.util.Log;
import com.google.android.gms.internal.zzbtl;
import com.google.android.gms.internal.zzbto;
import com.google.android.gms.internal.zzbtr;
import com.google.android.gms.internal.zzbxt;
import com.google.android.gms.internal.zzbts.zza;
import com.google.android.gms.internal.zzbts.zzb;
import com.google.android.gms.internal.zzbts.zzc;
import com.google.android.gms.internal.zzbts.zzd;
import com.google.android.gms.internal.zzbts.zze;
import com.google.android.gms.internal.zzbts.zzf;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
public class zzbtn implements Runnable {
public final Context mContext;
public final zzbto zzclY;
public final zzbto zzclZ;
public final zzbto zzcma;
public final zzbtr zzclQ;
public zzbtn(Context var1, zzbto var2, zzbto var3, zzbto var4, zzbtr var5) {
this.mContext = var1;
this.zzclY = var2;
this.zzclZ = var3;
this.zzcma = var4;
this.zzclQ = var5;
}
private zza zza(zzbto var1) {
zza var2 = new zza();
if(var1.zzace() != null) {
Map var3 = var1.zzace();
ArrayList var4 = new ArrayList();
Iterator var5 = var3.keySet().iterator();
while(var5.hasNext()) {
String var6 = (String)var5.next();
ArrayList var7 = new ArrayList();
Map var8 = (Map)var3.get(var6);
/* Crash is here when reading keySet() on null map */
Iterator var9 = var8.keySet().iterator();
while(var9.hasNext()) {
String var10 = (String)var9.next();
zzb var11 = new zzb();
var11.zzaB = var10;
var11.zzcml = (byte[])var8.get(var10);
var7.add(var11);
}
zzd var16 = new zzd();
var16.zzaGP = var6;
zzb[] var12 = new zzb[var7.size()];
var16.zzcmq = (zzb[])var7.toArray(var12);
var4.add(var16);
}
zzd[] var15 = new zzd[var4.size()];
var2.zzcmi = (zzd[])var4.toArray(var15);
}
if(var1.zzzD() != null) {
List var13 = var1.zzzD();
byte[][] var14 = new byte[var13.size()][];
var2.zzcmj = (byte[][])var13.toArray(var14);
}
var2.timestamp = var1.getTimestamp();
return var2;
}
public void run() {
zze var1 = new zze();
if(this.zzclY != null) {
var1.zzcmr = this.zza(this.zzclY);
}
if(this.zzclZ != null) {
var1.zzcms = this.zza(this.zzclZ);
}
if(this.zzcma != null) {
var1.zzcmt = this.zza(this.zzcma);
}
if(this.zzclQ != null) {
zzc var2 = new zzc();
var2.zzcmm = this.zzclQ.getLastFetchStatus();
var2.zzcmn = this.zzclQ.isDeveloperModeEnabled();
var2.zzcmo = this.zzclQ.zzacj();
var1.zzcmu = var2;
}
if(this.zzclQ != null && this.zzclQ.zzach() != null) {
ArrayList var8 = new ArrayList();
Map var3 = this.zzclQ.zzach();
Iterator var4 = var3.keySet().iterator();
while(var4.hasNext()) {
String var5 = (String)var4.next();
if(var3.get(var5) != null) {
zzf var6 = new zzf();
var6.zzaGP = var5;
var6.zzcmx = ((zzbtl)var3.get(var5)).zzacd();
var6.resourceId = ((zzbtl)var3.get(var5)).zzacc();
var8.add(var6);
}
}
zzf[] var11 = new zzf[var8.size()];
var1.zzcmv = (zzf[])var8.toArray(var11);
}
byte[] var9 = zzbxt.zzf(var1);
try {
FileOutputStream var10 = this.mContext.openFileOutput("persisted_config", 0);
var10.write(var9);
var10.close();
} catch (IOException var7) {
Log.e("AsyncPersisterTask", "Could not persist config.", var7);
}
}
}
此类用于 FirebaseRemoteConfig 类（参见方法 zzt()），如下所示：
https://gist.github.com/anonymous/e6f23c1dc37bf905a9224d8b72ab6cd9
我在我的应用程序类中使用 FirebaseRemoteConfig，如下所示：
public class MyApp extends MultiDexApplication {
public static boolean sound = true;
private static Context context;
private Typeface regularTypeFace;
private Typeface boldTypeFace;
private final String LOG_TAG = "MyApp";
private FirebaseRemoteConfig remoteConfig = null;
@Override
public void onCreate() {
super.onCreate();
Fabric.with(this, new Crashlytics());
context = getApplicationContext();
/* Try catch to handle any runtime exception thrown by firebase API */
try {
/* Initialize firebase app : Done to avoid crashes due to IllegalStateException - Default FirebaseApp is not initialized */
FirebaseApp.initializeApp(this);
/* Start to fetch Remote config parameters */
startConfigFetch();
} catch (Exception e){
e.printStackTrace();
}
}
/**
* Description : Fetches remote config params from firebase & uses the fetched values
*/
public void startConfigFetch() {
/* try to get the default instance of Firebase Remote config */
/* try-catch : To Resolve Crash #1399 */
try {
remoteConfig = FirebaseRemoteConfig.getInstance();
} catch (IllegalStateException e){
e.printStackTrace();
}
/* If we don't get an instance of Firebase remote config, then do nothing */
if (remoteConfig == null){
return;
}
FirebaseRemoteConfigSettings remoteConfigSettings = new FirebaseRemoteConfigSettings.Builder()
.setDeveloperModeEnabled(BuildConfig.DEBUG)
.build();
remoteConfig.setConfigSettings(remoteConfigSettings);
remoteConfig.setDefaults(R.xml.remote_config_defaults);
/* Time for which cache lives, for now its 0 ms */
long cacheExpiration = 0;
OnCompleteListener<Void> onCompleteListener = new OnCompleteListener<Void>() {
@Override
public void onComplete(@NonNull Task<Void> task) {
if (task.isSuccessful()) {
if (getContext() != null) {
onFetchConfigSuccess();
}
} else {
Log.d(LOG_TAG, "Stories Fetch Fail");
}
}
};
OnFailureListener onFailListener = new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Log.d(LOG_TAG, "Stories Fetch Fail in remote config");
}
};
remoteConfig.fetch(cacheExpiration).addOnCompleteListener(onCompleteListener).addOnFailureListener(onFailListener);
}
/**
* Called when fetch config is success
* */
private void onFetchConfigSuccess() {
/* Once the config is successfully fetched it must be activated before newly fetched */
/* values are returned (or can be used) */
remoteConfig.activateFetched();
/* Get dynamic stories string */
String dynamicStories = remoteConfig.getString(Common.KEY_DYNAMIC_STORIES_FIREBASE_CONFIG);
/* Get bundled stories (these are app-bundled stories & dynamic stories but part of bundled stories) */
String bundledStories = remoteConfig.getString(Common.KEY_BUNDLED_STORIES_FIREBASE_CONFIG);
/* Do something with dynamicStories & bundledStories values */
}
}
zzbto 类在这里：
https://gist.github.com/anonymous/e2f3a67e6fd3be51ba4456fe2e847890
请帮助解决此崩溃。