当 minifyEnabled 为 true 时，Android 应用程序崩溃

Question

我正在使用多模块应用程序，并且该应用程序minifyEnabled true在installed模块的 build.gradle 中崩溃。

以下是我从播放控制台检索到的反混淆堆栈跟踪。

 FATAL EXCEPTION: ControllerMessenger
Process: com.packagename, PID: 16978
java.lang.NullPointerException: Attempt to invoke interface method 'java.lang.Object java.util.List.get(int)' on a null object reference
    at com.packagename.login.Utils.AuthenticationActions.saveCredentials(AuthenticationActions.java)
    at com.packagename.login.LoginActivity$1$1.onCompleted(LoginActivity.java)
    at com.packagename.login.LoginActivity$1$1.onCompleted(LoginActivity.java)
    at com.koushikdutta.async.future.SimpleFuture.handleCallbackUnlocked(SimpleFuture.java)
    at com.koushikdutta.async.future.SimpleFuture.setComplete(SimpleFuture.java)
    at com.koushikdutta.async.future.SimpleFuture.setComplete(SimpleFuture.java)
    at com.koushikdutta.ion.IonRequestBuilder$EmitterTransform$1.onCompleted(IonRequestBuilder.java)
    at com.koushikdutta.async.future.SimpleFuture.handleCallbackUnlocked(SimpleFuture.java)
    at com.koushikdutta.async.future.SimpleFuture.setComplete(SimpleFuture.java)
    at com.koushikdutta.async.future.SimpleFuture.setComplete(SimpleFuture.java)
    at com.koushikdutta.ion.IonRequestBuilder$1.run(IonRequestBuilder.java)
    at com.koushikdutta.async.AsyncServer$RunnableWrapper.run(AsyncServer.java)
    at android.os.Handler.handleCallback(Handler.java:746)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at androidx.test.espresso.base.Interrogator.a(Interrogator.java:19)
    at androidx.test.espresso.base.UiControllerImpl.a(UiControllerImpl.java:166)
    at androidx.test.espresso.base.UiControllerImpl.a(UiControllerImpl.java:158)
    at androidx.test.espresso.base.UiControllerImpl.a(UiControllerImpl.java:34)
    at androidx.test.espresso.action.MotionEvents.a(MotionEvents.java:77)
    at androidx.test.espresso.action.MotionEvents.a(MotionEvents.java:52)
    at androidx.test.espresso.action.Tap.c(Tap.java:8)
    at androidx.test.espresso.action.Tap.b(Tap.java:18)
    at androidx.test.espresso.action.Tap$1.a(Tap.java:3)
    at androidx.test.espresso.action.GeneralClickAction.perform(GeneralClickAction.java:22)
    at androidx.test.espresso.ViewInteraction$SingleExecutionViewAction.perform(ViewInteraction.java:9)
    at androidx.test.espresso.ViewInteraction.a(ViewInteraction.java:79)
    at androidx.test.espresso.ViewInteraction.a(ViewInteraction.java:96)
    at androidx.test.espresso.ViewInteraction$1.call(ViewInteraction.java:3)
    at java.util.concurrent.FutureTask.run(FutureTask.java:237)
    at android.os.Handler.handleCallback(Handler.java:746)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:148)
    at android.app.ActivityThread.main(ActivityThread.java:5459)
    at java.lang.reflect.Method.invoke(Method.java)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)

我无法理解这段代码对应什么 'java.lang.Object java.util.List.get(int)'

我正在使用多个外部库，其中之一是ion koush。

我曾尝试将此添加到我的项目中的 proguard-rules.pro 文件中 -keep class com.koushikdutta.** { *;}。但这并没有产生任何成功。

Answer 1

当您的应用程序将 json 转换为 POJO 并且您启用了 minify 时，就会发生这种情况。缩小更改那些使转换变得不可能的 POJO（它会编译，但您所有的 POJO 属性将为空）。

将这些 POJO 添加-keep class com.packagename.<path to pojos> {*; }到您的 proguard-rules 文件中。

Answer 2

还要在所有 Pojo 文件的类名上方添加“@Keep”。