Android 引入 AndroidPdfViewer 问题：Duplicate class android.support.v4.app.AppLaunchChecker...

implementation'com.github.barteksc:android-pdf-viewer:3.2.0-beta.1'

• 在 Android 开发中，引入 AndroidPdfViewer 后，构建项目时，出现如下错误信息

Execution failed for task ':view:checkDebugDuplicateClasses'. > A failure occurred while executing com.android.build.gradle.internal.tasks.CheckDuplicatesRunnable > Duplicate class android.support.v4.app.AppLaunchChecker found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.app.FrameMetricsAggregator found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.app.FrameMetricsAggregator$FrameMetricsApi24Impl found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.app.FrameMetricsAggregator$FrameMetricsApi24Impl$1 found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.app.FrameMetricsAggregator$FrameMetricsBaseImpl found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.app.FrameMetricsAggregator$MetricType found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.app.INotificationSideChannel found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class android.support.v4.app.INotificationSideChannel$Stub found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class android.support.v4.app.INotificationSideChannel$Stub$Proxy found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class android.support.v4.app.NavUtils found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.app.TaskStackBuilder found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.app.TaskStackBuilder$SupportParentable found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.content.FileProvider found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.content.FileProvider$PathStrategy found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.content.FileProvider$SimplePathStrategy found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.content.MimeTypeFilter found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.content.PermissionChecker found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.content.PermissionChecker$PermissionResult found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.graphics.ColorUtils found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.graphics.drawable.IconCompatParcelizer found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class android.support.v4.graphics.drawable.RoundedBitmapDrawable found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.graphics.drawable.RoundedBitmapDrawable21 found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.graphics.drawable.RoundedBitmapDrawableFactory found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.graphics.drawable.RoundedBitmapDrawableFactory$DefaultRoundedBitmapDrawable found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.math.MathUtils found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) Duplicate class android.support.v4.os.IResultReceiver found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class android.support.v4.os.IResultReceiver$Stub found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class android.support.v4.os.IResultReceiver$Stub$Proxy found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class android.support.v4.os.ResultReceiver found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class android.support.v4.os.ResultReceiver$1 found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class android.support.v4.os.ResultReceiver$MyResultReceiver found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class android.support.v4.os.ResultReceiver$MyRunnable found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class android.support.v4.view.NestedScrollingChildHelper found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.view.NestedScrollingParentHelper found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.AutoScrollHelper found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.AutoScrollHelper$ClampedScroller found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.AutoScrollHelper$ScrollAnimationRunnable found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.ContentLoadingProgressBar found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.ContentLoadingProgressBar$1 found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.ContentLoadingProgressBar$2 found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.ListViewAutoScrollHelper found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.NestedScrollView found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.NestedScrollView$AccessibilityDelegate found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.NestedScrollView$OnScrollChangeListener found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.NestedScrollView$SavedState found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class android.support.v4.widget.NestedScrollView$SavedState$1 found in modules support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) and support-core-ui-26.1.0-runtime (com.android.support:support-core-ui:26.1.0) Duplicate class androidx.core.graphics.drawable.IconCompatParcelizer found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class androidx.core.internal.package-info found in modules core-1.9.0-runtime (androidx.core:core:1.9.0) and support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) Duplicate class androidx.versionedparcelable.CustomVersionedParcelable found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.NonParcelField found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.ParcelField found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.ParcelImpl found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.ParcelImpl$1 found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.ParcelUtils found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.VersionedParcel found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.VersionedParcel$1 found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.VersionedParcel$ParcelException found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.VersionedParcelParcel found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.VersionedParcelStream found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.VersionedParcelStream$FieldBuffer found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.VersionedParcelable found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0) Duplicate class androidx.versionedparcelable.VersionedParcelize found in modules versionedparcelable-1.1.1-runtime (androidx.versionedparcelable:versionedparcelable:1.1.1) and versionedparcelable-28.0.0-runtime (com.android.support:versionedparcelable:28.0.0)

# 解读 在模块 support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) 和 support-core-utils-26.1.0-runtime (com.android.support:support-core-utils:26.1.0) 中发现重复的类 android.support.v4.app.AppLaunchChecker ... 在模块 core-1.9.0-runtime (androidx.core:core:1.9.0) 和 support-compat-28.0.0-runtime (com.android.support:support-compat:28.0.0) 中发现重复的类 android.support.v4.app.INotificationSideChannel ...

问题原因

• 这个错误表示项目依赖环境中同时混用了AndroidX 库和 Support 库，Gradle 在构建时发现了这些重复的类定义

1. Support 库内部发生冲突，support-compat-28.0.0与support-core-utils-26.1.0等不同版本的 Support 模块间存在重复类

2. AndroidX 库与 Support 库发生冲突，androidx.core:core:1.9.0与com.android.support:support-compat:28.0.0等 AndroidX 库与 Support 库间存在重复类

处理策略

• 在gradle.properties文件中添加如下内容

android.useAndroidX=true android.enableJetifier=true

1. android.useAndroidX=true：表示项目使用 AndroidX 库

2. android.enableJetifier=true：表示允许 Gradle 自动重写旧的第三方库的二进制文件，将其中的旧支持库引用转换为 AndroidX 引用

• 以下是另外的一些尝试，但是无法处理该问题

dependencies{...configurations.all{resolutionStrategy{force'com.android.support:support-compat:28.0.0'force'com.android.support:support-core-utils:28.0.0'force'com.android.support:support-core-ui:28.0.0'force'com.android.support:versionedparcelable:28.0.0'force'com.android.support:loader:28.0.0'force'com.android.support:support-fragment:28.0.0'}}android{configurations{all*.exclude group:'com.android.support',module:'support-compat'}}}