如何缩小代码 -65k 方法限制在德克斯

我有一个相当大的 Android 应用程序,依赖于许多图书馆项目。Android 编译器对每个。我要超过那个数字。

当达到方法限制时,基本上有两条路径可以选择(至少我知道)。

1)缩小代码

2)建立多个 dex 文件(看看这篇博文)

我仔细研究了这两个问题,试图找出是什么导致我的方法计数如此之高。GoogleDriveAPI 占用了最大的块,其中对 Guava 的依赖超过12,000个。驱动器 API v2的总库超过23,000!

我的问题是,你觉得我该怎么做?我是否应该将 Google Drive 整合作为我的应用程序的一个功能?有没有办法缩小 API (是的,我使用 proGuard) ?我是否应该采用多重 dex 路线(这看起来相当痛苦,尤其是处理第三方 API) ?

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I think that in the long run breaking your app in multiple dex would be the best way.

Use proguard to lighten your apk as methods that are unused will not be in your final build. Double check you have following in your proguard config file to use proguard with guava (my apologies if you already have this, it wasn't known at time of writing) :

# Guava exclusions (http://code.google.com/p/guava-libraries/wiki/UsingProGuardWithGuava)
-dontwarn sun.misc.Unsafe
-dontwarn com.google.common.collect.MinMaxPriorityQueue
-keepclasseswithmembers public class * {
public static void main(java.lang.String[]);
}


# Guava depends on the annotation and inject packages for its annotations, keep them both
-keep public class javax.annotation.**
-keep public class javax.inject.**

In addition, if you are using ActionbarSherlock, switching to the v7 appcompat support library will also reduce your method count by a lot (based on personal experience). Instructions are located :

You could use Jar Jar Links to shrink huge external libraries like Google Play Services (16K methods!)

In your case you will just rip everything from Google Play Services jar except common internal and drive sub-packages.

Multi-dex support is going to be the official solution for this issue. See my answer here for the details.

It looks like Google has finally implementing a workaround/fix for surpassing the 65K method limit of dex files.

About the 65K Reference Limit

Android application (APK) files contain executable bytecode files in the form of Dalvik Executable (DEX) files, which contain the compiled code used to run your app. The Dalvik Executable specification limits the total number of methods that can be referenced within a single DEX file to 65,536, including Android framework methods, library methods, and methods in your own code. Getting past this limit requires that you configure your app build process to generate more than one DEX file, known as a multidex configuration.

Multidex support prior to Android 5.0

Versions of the platform prior to Android 5.0 use the Dalvik runtime for executing app code. By default, Dalvik limits apps to a single classes.dex bytecode file per APK. In order to get around this limitation, you can use the multidex support library, which becomes part of the primary DEX file of your app and then manages access to the additional DEX files and the code they contain.

Multidex support for Android 5.0 and higher

Android 5.0 and higher uses a runtime called ART which natively supports loading multiple dex files from application APK files. ART performs pre-compilation at application install time which scans for classes(..N).dex files and compiles them into a single .oat file for execution by the Android device. For more information on the Android 5.0 runtime, see Introducing ART.

See: Building Apps with Over 65K Methods


Multidex Support Library

This library provides support for building apps with multiple Dalvik Executable (DEX) files. Apps that reference more than 65536 methods are required to use multidex configurations. For more information about using multidex, see Building Apps with Over 65K Methods.

This library is located in the /extras/android/support/multidex/ directory after you download the Android Support Libraries. The library does not contain user interface resources. To include it in your application project, follow the instructions for Adding libraries without resources.

The Gradle build script dependency identifier for this library is as follows:

com.android.support:multidex:1.0.+ This dependency notation specifies the release version 1.0.0 or higher.


You should still avoid hitting the 65K method limit by actively using proguard and reviewing your dependencies.

Play Services 6.5+ helps: http://android-developers.blogspot.com/2014/12/google-play-services-and-dex-method.html

"Starting with version 6.5, of Google Play services, you’ll be able to pick from a number of individual APIs, and you can see"

...

"this will transitively include the ‘base’ libraries, which are used across all APIs."

This is good news, for a simple game for example you probably only need the base, games and maybe drive.

"The complete list of API names is below. More details can be found on the Android Developer site.:

  • com.google.android.gms:play-services-base:6.5.87
  • com.google.android.gms:play-services-ads:6.5.87
  • com.google.android.gms:play-services-appindexing:6.5.87
  • com.google.android.gms:play-services-maps:6.5.87
  • com.google.android.gms:play-services-location:6.5.87
  • com.google.android.gms:play-services-fitness:6.5.87
  • com.google.android.gms:play-services-panorama:6.5.87
  • com.google.android.gms:play-services-drive:6.5.87
  • com.google.android.gms:play-services-games:6.5.87
  • com.google.android.gms:play-services-wallet:6.5.87
  • com.google.android.gms:play-services-identity:6.5.87
  • com.google.android.gms:play-services-cast:6.5.87
  • com.google.android.gms:play-services-plus:6.5.87
  • com.google.android.gms:play-services-appstate:6.5.87
  • com.google.android.gms:play-services-wearable:6.5.87
  • com.google.android.gms:play-services-all-wear:6.5.87

In versions of Google Play services prior to 6.5, you had to compile the entire package of APIs into your app. In some cases, doing so made it more difficult to keep the number of methods in your app (including framework APIs, library methods, and your own code) under the 65,536 limit.

From version 6.5, you can instead selectively compile Google Play service APIs into your app. For example, to include only the Google Fit and Android Wear APIs, replace the following line in your build.gradle file:

compile 'com.google.android.gms:play-services:6.5.87'

with these lines:

compile 'com.google.android.gms:play-services-fitness:6.5.87'
compile 'com.google.android.gms:play-services-wearable:6.5.87'

for more reference, you can click here

you can use the multidex support library for that, To enable multidex

1) include it in dependencies:

dependencies {
...
compile 'com.android.support:multidex:1.0.0'
}

2) Enable it in your app:

defaultConfig {
...
minSdkVersion 14
targetSdkVersion 21
....
multiDexEnabled true
}

3) if you have a application class for your app then Override the attachBaseContext method like this:

package ....;
...
import android.support.multidex.MultiDex;


public class MyApplication extends Application {
....
@Override
protected void attachBaseContext(Context context) {
super.attachBaseContext(context);
MultiDex.install(this);
}
}

4) if you don't have a application class for your application then register android.support.multidex.MultiDexApplication as your application in your manifest file. like this:

<application
...
android:name="android.support.multidex.MultiDexApplication">
...
</application>

and it should work fine!

If not to use multidex which making build process very slow. You can do the following. As yahska mentioned use specific google play service library. For most cases only this is needed.

compile 'com.google.android.gms:play-services-base:6.5.+'

Here is all available packages Selectively compiling APIs into your executable

If this will be not enough you can use gradle script. Put this code in file 'strip_play_services.gradle'

def toCamelCase(String string) {
String result = ""
string.findAll("[^\\W]+") { String word ->
result += word.capitalize()
}
return result
}


afterEvaluate { project ->
Configuration runtimeConfiguration = project.configurations.getByName('compile')
println runtimeConfiguration
ResolutionResult resolution = runtimeConfiguration.incoming.resolutionResult
// Forces resolve of configuration
ModuleVersionIdentifier module = resolution.getAllComponents().find {
it.moduleVersion.name.equals("play-services")
}.moduleVersion




def playServicesLibName = toCamelCase("${module.group} ${module.name} ${module.version}")
String prepareTaskName = "prepare${playServicesLibName}Library"
File playServiceRootFolder = project.tasks.find { it.name.equals(prepareTaskName) }.explodedDir




def tmpDir = new File(project.buildDir, 'intermediates/tmp')
tmpDir.mkdirs()
def libFile = new File(tmpDir, "${playServicesLibName}.marker")


def strippedClassFileName = "${playServicesLibName}.jar"
def classesStrippedJar = new File(tmpDir, strippedClassFileName)


def packageToExclude = ["com/google/ads/**",
"com/google/android/gms/actions/**",
"com/google/android/gms/ads/**",
// "com/google/android/gms/analytics/**",
"com/google/android/gms/appindexing/**",
"com/google/android/gms/appstate/**",
"com/google/android/gms/auth/**",
"com/google/android/gms/cast/**",
"com/google/android/gms/drive/**",
"com/google/android/gms/fitness/**",
"com/google/android/gms/games/**",
"com/google/android/gms/gcm/**",
"com/google/android/gms/identity/**",
"com/google/android/gms/location/**",
"com/google/android/gms/maps/**",
"com/google/android/gms/panorama/**",
"com/google/android/gms/plus/**",
"com/google/android/gms/security/**",
"com/google/android/gms/tagmanager/**",
"com/google/android/gms/wallet/**",
"com/google/android/gms/wearable/**"]


Task stripPlayServices = project.tasks.create(name: 'stripPlayServices', group: "Strip") {
inputs.files new File(playServiceRootFolder, "classes.jar")
outputs.dir playServiceRootFolder
description 'Strip useless packages from Google Play Services library to avoid reaching dex limit'


doLast {
def packageExcludesAsString = packageToExclude.join(",")
if (libFile.exists()
&& libFile.text == packageExcludesAsString
&& classesStrippedJar.exists()) {
println "Play services already stripped"
copy {
from(file(classesStrippedJar))
into(file(playServiceRootFolder))
rename { fileName ->
fileName = "classes.jar"
}
}
} else {
copy {
from(file(new File(playServiceRootFolder, "classes.jar")))
into(file(playServiceRootFolder))
rename { fileName ->
fileName = "classes_orig.jar"
}
}
tasks.create(name: "stripPlayServices" + module.version, type: Jar) {
destinationDir = playServiceRootFolder
archiveName = "classes.jar"
from(zipTree(new File(playServiceRootFolder, "classes_orig.jar"))) {
exclude packageToExclude
}
}.execute()
delete file(new File(playServiceRootFolder, "classes_orig.jar"))
copy {
from(file(new File(playServiceRootFolder, "classes.jar")))
into(file(tmpDir))
rename { fileName ->
fileName = strippedClassFileName
}
}
libFile.text = packageExcludesAsString
}
}
}


project.tasks.findAll {
it.name.startsWith('prepare') && it.name.endsWith('Dependencies')
}.each { Task task ->
task.dependsOn stripPlayServices
}
project.tasks.findAll { it.name.contains(prepareTaskName) }.each { Task task ->
stripPlayServices.mustRunAfter task
}

}

Then apply this script in your build.gradle, like this

apply plugin: 'com.android.application'
apply from: 'strip_play_services.gradle'

For Eclipse users not using Gradle, there are tools that will break down the Google Play Services jar and rebuild it with only the parts you want.

I use strip_play_services.sh by dextorer.

It can be difficult to know exactly which services to include because there are some internal dependencies but you can start small and add to the configuration if it turns out that needed things are missing.

If using Google Play Services, you may know that it adds 20k+ methods. As already mentioned, Android Studio has the option for modular inclusion of specific services, but users stuck with Eclipse have to take modularisation into their own hands :(

Fortunately there's a shell script that makes the job fairly easy. Just extract to the google play services jar directory, edit the supplied .conf file as needed and execute the shell script.

An example of its use is here.

If using Google Play Services, you may know that it adds 20k+ methods. As already mentioned, Android Studio has the option for modular inclusion of specific services, but users stuck with Eclipse have to take modularisation into their own hands :(

Fortunately there's a shell script that makes the job fairly easy. Just extract to the google play services jar directory, edit the supplied .conf file as needed and execute the shell script.

An example of its use is here.

Just like he said, I replaces compile 'com.google.android.gms:play-services:9.0.0' just with the libraries that I needed and it worked.