ProGuard 导致应用滞后

Question

我正在尝试使用 proguard 混淆代码，因此我在发布构建类型中启用了 minify：

buildTypes {
    debug {
        minifyEnabled false
    }
    release {
        minifyEnabled true
        proguardFiles getDefaultProguardFile('proguard-android.txt')
    }
}

但是当我生成“发布 apk”并安装它后，应用程序运行速度变慢（滞后）..为什么在启用 minify 时会发生这种情况？ 这是我的依赖项：

dependencies {
    compile 'com.android.support:support-v4:25.3.1'
    compile 'com.android.support:recyclerview-v7:25.3.1'
    compile 'com.android.support:palette-v7:25.3.1'
    compile 'com.google.protobuf.nano:protobuf-javanano:3.0.0-alpha-2'
    compile 'com.jrummyapps:colorpicker:2.1.6'
    compile 'org.apache.commons:commons-lang3:3.4'
    compile 'com.android.support:appcompat-v7:25.3.1'
    compile 'com.android.support:design:25.3.1'
    compile project(':library')

    testCompile 'junit:junit:4.12'
    androidTestCompile 'com.android.support.test:runner:0.5'
    androidTestCompile 'com.android.support.test.uiautomator:uiautomator-v18:2.1.2'
    androidTestCompile 'com.android.support:support-annotations:25.3.1'
}

这是我的proguard-android.txt

# This is a configuration file for ProGuard.
# http://proguard.sourceforge.net/index.html#manual/usage.html

-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-verbose

# Optimization is turned off by default. Dex does not like code run
# through the ProGuard optimize and preverify steps (and performs some
# of these optimizations on its own).
-dontoptimize
-dontpreverify
# 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.

-keepattributes *Annotation*
-keep public class com.google.vending.licensing.ILicensingService
-keep public class com.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.
# see http://proguard.sourceforge.net/manual/examples.html#beans
-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 android.os.Parcelable$Creator CREATOR;
}

-keepclassmembers class **.R$* {
    public static <fields>;
}

# The support library 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.
-dontwarn android.support.**

# Understand the @Keep support annotation.
-keep class android.support.annotation.Keep

-keep @android.support.annotation.Keep class * {*;}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <methods>;
}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <fields>;
}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <init>(...);
}

我尝试添加：

-keep class com.mylibrary.**
-keep interface com.mylibrary.**
-keep enum com.mylibrary.**

我的库依赖：

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.3.1'
    compile 'com.android.support:palette-v7:25.3.1'
    testCompile 'junit:junit:4.12'
    compile 'com.google.code.gson:gson:2.8.0'
    compile 'org.jetbrains:annotations-java5:15.0'
}

Answer 1

虽然proguard-android.txt 中的 cmets 指定了一些原因，但我很惊讶地看到禁用某些优化的标志，因为默认自动生成的 proguard-android.txt 文件在创建新的 Android 项目时不包含此类标志。尝试删除以下行，看看是否有改进：

-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontoptimize
-dontpreverify

文件的其余部分似乎很好，虽然我没有检查所有正在使用的库，但我检查了几个并意识到您已经为它们添加了必要的例外。

如果没有解决，您必须确保正确添加正在使用的库的异常，并检查 proguard-android.txt 内的 library 模块，因为它在依赖项中被引用.

Answer 2

ProGuard 不会导致应用程序在运行时出现延迟。这可能是由于您的库之一包含在 gradle 文件中。

Answer 3

我强烈建议您使用 Android Studio Profiler 查看应用的行为方式和行为方式。我的意思是内存、CPU、网络等。 保存结果以进行比较，然后尝试仅使用 proguard 更改的相同应用程序版本。 性能影响不太可能来自proguard。 如果可能，请在此处传递结果和您的观察结果以进行进一步分析。 另请注意，构建类型也有所不同，您在调试/发布风格中是否有不同的代码？

Answer 4

Java 在第一次退出时总是运行缓慢。因为它必须被加载和解释。再次运行测试。看看这个问题。

Java program runs slower when code that is never executed is commented out