最近在搞Flutter，在模拟器调试一切正常，但是flutter build apk以后真机闪退，看了下日志，报错如下：
E/flutter ( 5319): [ERROR:flutter/shell/platform/android/platform_view_android_jni.cc(39)] java.lang.NoClassDefFoundError: g.a.b.o3
E/flutter ( 5319): at g.a.b.r.v(Unknown Source:0)
E/flutter ( 5319): at com.huangyunkun.kiwi.a.a(Unknown Source:102)
E/flutter ( 5319): at com.huangyunkun.kiwi.MainActivity$a.a(Unknown Source:153)
E/flutter ( 5319): at c.a.c.a.j$a.a(Unknown Source:17)
E/flutter ( 5319): at io.flutter.embedding.engine.e.b.a(Unknown Source:57)
E/flutter ( 5319): at io.flutter.embedding.engine.FlutterJNI.handlePlatformMessage(Unknown Source:4)
E/flutter ( 5319): at android.os.MessageQueue.nativePollOnce(Native Method)
E/flutter ( 5319): at android.os.MessageQueue.next(MessageQueue.java:326)
E/flutter ( 5319): at android.os.Looper.loop(Looper.java:165)
E/flutter ( 5319): at android.app.ActivityThread.main(ActivityThread.java:6815)
E/flutter ( 5319): at java.lang.reflect.Method.invoke(Native Method)
E/flutter ( 5319): at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
E/flutter ( 5319): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)
E/flutter ( 5319): Caused by: java.lang.ExceptionInInitializerError
E/flutter ( 5319): at g.a.b.r.a(Unknown Source:0)
E/flutter ( 5319): at g.a.b.r.a(Unknown Source:4)
E/flutter ( 5319): at g.a.b.r.u(Unknown Source:1)
E/flutter ( 5319): at com.huangyunkun.kiwi.a.a(Unknown Source:15)
E/flutter ( 5319): ... 11 more
E/flutter ( 5319): Caused by: java.lang.IllegalStateException: Failed to create VMBridge instance
E/flutter ( 5319): at g.a.b.o3.b(Unknown Source:40)
E/flutter ( 5319): at g.a.b.o3.<clinit>(Unknown Source:0)
E/flutter ( 5319): ... 15 more
E/flutter ( 5319):
F/flutter ( 5319): [FATAL:flutter/shell/platform/android/platform_view_android_jni.cc(76)] Check failed: CheckException(env).
看java.lang.NoClassDefFoundError: g.a.b.o3应该是android的混淆没对，但是找了一圈proguard却找不到。
查看下文档发现现在已经用R8了，不过默认还是兼容proguard rule的，那么首先先把日志输出看下。
默认配置是
# This is a configuration file for ProGuard.
# http://proguard.sourceforge.net/index.html#manual/usage.html
#
# Starting with version 2.2 of the Android plugin for Gradle, this file is distributed together with
# the plugin and unpacked at build-time. The files in $ANDROID_HOME are no longer maintained and
# will be ignored by new version of the Android plugin for Gradle.
# Optimization is turned off by default. Dex does not like code run
# through the ProGuard optimize steps (and performs some
# of these optimizations on its own).
# Note that if you want to enable optimization, you cannot just
# include optimization flags in your own project configuration file;
# instead you will need to point to the
# "proguard-android-optimize.txt" file instead of this one from your
# project.properties file.
-dontoptimize
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-verbose
# Preserve some attributes that may be required for reflection.
-keepattributes *Annotation*,Signature,InnerClasses,EnclosingMethod
-keep public class com.google.vending.licensing.ILicensingService
-keep public class com.android.vending.licensing.ILicensingService
-keep public class com.google.android.vending.licensing.ILicensingService
-dontnote com.android.vending.licensing.ILicensingService
-dontnote com.google.vending.licensing.ILicensingService
-dontnote com.google.android.vending.licensing.ILicensingService
# For native methods, see http://proguard.sourceforge.net/manual/examples.html#native
-keepclasseswithmembernames class * {
native <methods>;
}
# Keep setters in Views so that animations can still work.
-keepclassmembers public class * extends android.view.View {
void set*(***);
*** get*();
}
# We want to keep methods in Activity that could be used in the XML attribute onClick.
-keepclassmembers class * extends android.app.Activity {
public void *(android.view.View);
}
# For enumeration classes, see http://proguard.sourceforge.net/manual/examples.html#enumerations
-keepclassmembers enum * {
public static **[] values();
public static ** valueOf(java.lang.String);
}
-keepclassmembers class * implements android.os.Parcelable {
public static final ** CREATOR;
}
-keepclassmembers class **.R$* {
public static <fields>;
}
# Preserve annotated Javascript interface methods.
-keepclassmembers class * {
@android.webkit.JavascriptInterface <methods>;
}
# The support libraries contains references to newer platform versions.
# Don't warn about those in case this app is linking against an older
# platform version. We know about them, and they are safe.
-dontnote android.support.**
-dontnote androidx.**
-dontwarn android.support.**
-dontwarn androidx.**
# This class is deprecated, but remains for backward compatibility.
-dontwarn android.util.FloatMath
# Understand the @Keep support annotation.
-keep class android.support.annotation.Keep
-keep class androidx.annotation.Keep
-keep @android.support.annotation.Keep class * {*;}
-keep @androidx.annotation.Keep class * {*;}
-keepclasseswithmembers class * {
@android.support.annotation.Keep <methods>;
}
-keepclasseswithmembers class * {
@androidx.annotation.Keep <methods>;
}
-keepclasseswithmembers class * {
@android.support.annotation.Keep <fields>;
}
-keepclasseswithmembers class * {
@androidx.annotation.Keep <fields>;
}
-keepclasseswithmembers class * {
@android.support.annotation.Keep <init>(...);
}
-keepclasseswithmembers class * {
@androidx.annotation.Keep <init>(...);
}
# These classes are duplicated between android.jar and org.apache.http.legacy.jar.
-dontnote org.apache.http.**
-dontnote android.net.http.**
# These classes are duplicated between android.jar and core-lambda-stubs.jar.
-dontnote java.lang.invoke.**
# Build the ephemeral app in a module project.
# Prevents: Warning: library class <plugin-package> depends on program class io.flutter.plugin.**
# This is due to plugins (libraries) depending on the embedding (the program jar)
-dontwarn io.flutter.plugin.**
# The android.** package is provided by the OS at runtime.
-dontwarn android.**
-printconfiguration full-r8-config.txt
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:25
-keep class androidx.core.app.CoreComponentFactory { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:126
-keep class com.google.android.gms.common.api.GoogleApiActivity { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:97
-keep class com.google.android.gms.measurement.AppMeasurementInstallReferrerReceiver { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:111
-keep class com.google.android.gms.measurement.AppMeasurementJobService { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:92
-keep class com.google.android.gms.measurement.AppMeasurementReceiver { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:107
-keep class com.google.android.gms.measurement.AppMeasurementService { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:51
-keep class com.google.firebase.components.ComponentDiscoveryService { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:117
-keep class com.google.firebase.iid.FirebaseInstanceIdReceiver { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:81
-keep class com.google.firebase.perf.provider.FirebasePerfProvider { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:131
-keep class com.google.firebase.provider.FirebaseInitProvider { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:30
-keep class com.huangyunkun.kiwi.MainActivity { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:25
-keep class io.flutter.app.FlutterApplication { <init>(); }
# Referenced at /Users/huangyunkun/OpenSource/kiwi/build/app/intermediates/merged_manifests/release/AndroidManifest.xml:87
-keep class io.flutter.plugins.urllauncher.WebViewActivity { <init>(); }
# Needed when app is not using OkHttp
-dontwarn okio.**
# Needed when app's compileSdkVersion < 24
-dontwarn com.google.firebase.perf.network.**
# We keep all fields for every generated proto file as the runtime uses
# reflection over them that ProGuard cannot detect. Without this keep
# rule, fields may be removed that would cause runtime failures.
-keepclassmembers class * extends com.google.android.gms.internal.firebase-perf.zzep {
<fields>;
}
# We keep all fields for every generated proto file as the runtime uses
# reflection over them that ProGuard cannot detect. Without this keep
# rule, fields may be removed that would cause runtime failures.
-keepclassmembers class * extends com.google.android.gms.internal.measurement.zzfd {
<fields>;
}
# We keep all fields for every generated proto file as the runtime uses
# reflection over them that ProGuard cannot detect. Without this keep
# rule, fields may be removed that would cause runtime failures.
-keepclassmembers class * extends com.google.android.gms.internal.measurement.zzfd {
<fields>;
}
# We keep all fields for every generated proto file as the runtime uses
# reflection over them that ProGuard cannot detect. Without this keep
# rule, fields may be removed that would cause runtime failures.
-keepclassmembers class * extends com.google.android.gms.internal.measurement.zzfd {
<fields>;
}
# We keep all fields for every generated proto file as the runtime uses
# reflection over them that ProGuard cannot detect. Without this keep
# rule, fields may be removed that would cause runtime failures.
-keepclassmembers class * extends com.google.android.gms.internal.clearcut.zzcg {
<fields>;
}
# We keep all fields for every generated proto file as the runtime uses
# reflection over them that ProGuard cannot detect. Without this keep
# rule, fields may be removed that would cause runtime failures.
-keepclassmembers class * extends com.google.android.gms.internal.firebase_remote_config.zzhi {
<fields>;
}
# Auto-generated proguard rule with obfuscated symbol
-keepclassmembers class * {
@com.google.android.gms.internal.firebase_remote_config.zzcc <fields>;
}
# b/35135904 Ensure that proguard will not strip the mResultGuardian.
-keepclassmembers class com.google.android.gms.common.api.internal.BasePendingResult {
com.google.android.gms.common.api.internal.BasePendingResult$ReleasableResultGuardian mResultGuardian;
}
-dontwarn com.google.firebase.platforminfo.KotlinDetector
# We keep all fields for every generated proto file as the runtime uses
# reflection over them that ProGuard cannot detect. Without this keep
# rule, fields may be removed that would cause runtime failures.
-keepclassmembers class * extends com.google.android.gms.internal.measurement.zzfd {
<fields>;
}
# We keep all fields for every generated proto file as the runtime uses
# reflection over them that ProGuard cannot detect. Without this keep
# rule, fields may be removed that would cause runtime failures.
-keepclassmembers class * extends com.google.android.gms.internal.measurement.zzfd {
<fields>;
}
# We keep all fields for every generated proto file as the runtime uses
# reflection over them that ProGuard cannot detect. Without this keep
# rule, fields may be removed that would cause runtime failures.
-keepclassmembers class * extends com.google.android.gms.internal.measurement.zzfd {
<fields>;
}
# Proguard flags for consumers of the Google Play services SDK
# https://developers.google.com/android/guides/setup#add_google_play_services_to_your_project
# Keep SafeParcelable NULL value, needed for reflection by DowngradeableSafeParcel
-keepclassmembers public class com.google.android.gms.common.internal.safeparcel.SafeParcelable {
public static final *** NULL;
}
# Needed for Parcelable/SafeParcelable classes & their creators to not get renamed, as they are
# found via reflection.
-keep class com.google.android.gms.common.internal.ReflectedParcelable
-keepnames class * implements com.google.android.gms.common.internal.ReflectedParcelable
-keepclassmembers class * implements android.os.Parcelable {
public static final *** CREATOR;
}
# Keep the classes/members we need for client functionality.
-keep @interface androidx.annotation.Keep
-keep @androidx.annotation.Keep class *
-keepclasseswithmembers class * {
@androidx.annotation.Keep <fields>;
}
-keepclasseswithmembers class * {
@androidx.annotation.Keep <methods>;
}
# Keep the names of classes/members we need for client functionality.
-keep @interface com.google.android.gms.common.annotation.KeepName
-keepnames @com.google.android.gms.common.annotation.KeepName class *
-keepclassmembernames class * {
@com.google.android.gms.common.annotation.KeepName *;
}
# Keep Dynamite API entry points
-keep @interface com.google.android.gms.common.util.DynamiteApi
-keep @com.google.android.gms.common.util.DynamiteApi public class * {
public <fields>;
public <methods>;
}
# Needed when building against pre-Marshmallow SDK.
-dontwarn android.security.NetworkSecurityPolicy
# Needed when building against Marshmallow SDK.
-dontwarn android.app.Notification
# Protobuf has references not on the Android boot classpath
-dontwarn sun.misc.Unsafe
-dontwarn libcore.io.Memory
# Internal Google annotations for generating Proguard keep rules.
-dontwarn com.google.android.apps.common.proguard.UsedBy*
# Annotations referenced by the SDK but whose definitions are contained in
# non-required dependencies.
-dontwarn javax.annotation.**
-dontwarn org.checkerframework.**
# Copyright 2018 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
# We need to avoid obfuscating the support library boundary interface because
# this API is shared with the Android Support Library.
# Note that we only 'keep' the package org.chromium.support_lib_boundary itself,
# any sub-packages of that package can still be obfuscated.
-keep public class org.chromium.support_lib_boundary.* { public *; }
# Copyright (C) 2018 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Prevent WebViewClientCompat from being renamed, since chromium depends on this name.
-keepnames public class androidx.webkit.WebViewClientCompat
# Copyright (C) 2016 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# CoordinatorLayout resolves the behaviors of its child components with reflection.
-keep public class * extends androidx.coordinatorlayout.widget.CoordinatorLayout$Behavior {
public <init>(android.content.Context, android.util.AttributeSet);
public <init>();
}
# Make sure we keep annotations for CoordinatorLayout's DefaultBehavior and ViewPager's DecorView
-keepattributes *Annotation*
# aapt2 is not (yet) keeping FQCNs defined in the appComponentFactory <application> attribute
-keep class androidx.core.app.CoreComponentFactory
# JSR 305 annotations are for embedding nullability information.
-dontwarn javax.annotation.**
# A resource is loaded with a relative path so the package of this class must be preserved.
-keepnames class okhttp3.internal.publicsuffix.PublicSuffixDatabase
# Animal Sniffer compileOnly dependency to ensure APIs are compatible with older versions of Java.
-dontwarn org.codehaus.mojo.animal_sniffer.*
# OkHttp platform used only on JVM and when Conscrypt dependency is available.
-dontwarn okhttp3.internal.platform.ConscryptPlatform
-keepattributes *Annotation*
-keepclassmembers enum androidx.lifecycle.Lifecycle$Event {
<fields>;
}
-keep !interface * implements androidx.lifecycle.LifecycleObserver {
}
-keep class * implements androidx.lifecycle.GeneratedAdapter {
<init>(...);
}
-keepclassmembers class ** {
@androidx.lifecycle.OnLifecycleEvent *;
}
-keep public class * extends androidx.versionedparcelable.VersionedParcelable
-keep public class android.support.**Parcelizer { *; }
-keep public class androidx.**Parcelizer { *; }
-keep public class androidx.versionedparcelable.ParcelImpl
-dontwarn com.google.firebase.components.Component$Instantiation
-dontwarn com.google.firebase.components.Component$ComponentType
-keep class * implements com.google.firebase.components.ComponentRegistrar
-keepclassmembers,allowobfuscation class * extends androidx.lifecycle.ViewModel {
<init>();
}
-keepclassmembers,allowobfuscation class * extends androidx.lifecycle.AndroidViewModel {
<init>(android.app.Application);
}
-keep,allowobfuscation @interface androidx.annotation.Keep
-keep @androidx.annotation.Keep class * {*;}
-keepclasseswithmembers class * {
@androidx.annotation.Keep <methods>;
}
-keepclasseswithmembers class * {
@androidx.annotation.Keep <fields>;
}
-keepclasseswithmembers class * {
@androidx.annotation.Keep <init>(...);
}
-ignorewarnings
因为唯一和原生有关的就是自定义了一个rhino的channel，直接keep即可
-keep class org.mozilla.javascript.** { *; }
如果是开发阶段也可以先关闭混淆，后面统一处理
android.enableR8=false
参考
https://developer.android.com/studio/build/shrink-code#troubleshoot
https://developer.android.com/studio/build/shrink-code#configuration-files