Gradle依赖项学习之依赖冲突解决总结

本文转载自paincker网,由jzj1993原创

Gradle是一个非常好用的编译工具，特别是继承了maven的依赖项管理功能，需要的Library不需要像传统IDE一样手动下载复制到项目中，只需要简单的写一行gradle脚本，就能自动下载下来并编译。

但是有时候会出现各种不明情况的报错，最常见的一种原因就是依赖项版本冲突。

每个模块都可能依赖其他模块，这些模块又会依赖别的模块。而一个项目中的多个模块，对同一个模块的不同版本有依赖，就可能产生冲突。

通过gradle命令查看依赖树，可以比较直观的看到冲突。具体方法是在模块所在的目录，也即build.gradle所在目录下执行gradle dependencies（需要将gradle加入PATH环境变量），执行结果如图。

Transitive

Transitive用于自动处理子依赖项。默认为true，gradle自动添加子依赖项，形成一个多层树形结构；设置为false，则需要手动添加每个依赖项。

案例

以安卓单元测试espresso的配置为例，gradle依赖如下：

  
dependencies {
   androidTestCompile('com.android.support.test:runner:0.2')
   androidTestCompile('com.android.support.test:rules:0.2')
   androidTestCompile('com.android.support.test.espresso:espresso-core:2.1')
}

运行gradle dependencies的结果如下。可以看到每个包的依赖项都被递归分析并添加进来。

  
+--- com.android.support.test:runner:0.2
|    +--- junit:junit-dep:4.10
|    |    --- org.hamcrest:hamcrest-core:1.1
|    +--- com.android.support.test:exposed-instrumentation-api-publish:0.2
|    --- com.android.support:support-annotations:22.0.0
+--- com.android.support.test:rules:0.2
|    --- com.android.support.test:runner:0.2 ()
--- com.android.support.test.espresso:espresso-core:2.1
     +--- com.android.support.test:rules:0.2 ()
     +--- com.squareup:javawriter:2.1.1
     +--- org.hamcrest:hamcrest-integration:1.1
     |    --- org.hamcrest:hamcrest-core:1.1
     +--- com.android.support.test.espresso:espresso-idling-resource:2.1
     +--- org.hamcrest:hamcrest-library:1.1
     |    --- org.hamcrest:hamcrest-core:1.1
     +--- javax.inject:javax.inject:1
     +--- com.google.code.findbugs:jsr305:2.0.1
     +--- com.android.support.test:runner:0.2 ()
     +--- javax.annotation:javax.annotation-api:1.2
     --- org.hamcrest:hamcrest-core:1.1

统一指定transitive

可以给dependencies统一指定transitive为false，再次执行dependencies可以看到如下结果。

  
configurations.all {
   transitive = false
}
dependencies {
   androidTestCompile('com.android.support.test:runner:0.2')
   androidTestCompile('com.android.support.test:rules:0.2')
   androidTestCompile('com.android.support.test.espresso:espresso-core:2.1')
}

  
+--- com.android.support.test:runner:0.2
+--- com.android.support.test:rules:0.2
--- com.android.support.test.espresso:espresso-core:2.1

单独指定依赖项的transitive

  
dependencies {
   androidTestCompile('com.android.support.test:runner:0.2')
   androidTestCompile('com.android.support.test:rules:0.2')
   androidTestCompile('com.android.support.test.espresso:espresso-core:2.1') {
       transitive = false
   }
}

版本冲突

在同一个配置下（例如androidTestCompile），某个模块的不同版本同时被依赖时，默认使用最新版，gradle同步时不会报错。例如下面的hamcrest-core和runner。

  
dependencies {
   androidTestCompile('com.android.support.test:runner:0.4')
   androidTestCompile('com.android.support.test:rules:0.2')
   androidTestCompile('com.android.support.test.espresso:espresso-core:2.1')
}

  
+--- com.android.support.test:runner:0.4
|    +--- com.android.support:support-annotations:23.0.1
|    +--- junit:junit:4.12
|    |    --- org.hamcrest:hamcrest-core:1.3
|    --- com.android.support.test:exposed-instrumentation-api-publish:0.4
+--- com.android.support.test:rules:0.2
|    --- com.android.support.test:runner:0.2 -> 0.4 ()
--- com.android.support.test.espresso:espresso-core:2.1
     +--- com.android.support.test:rules:0.2 ()
     +--- com.squareup:javawriter:2.1.1
     +--- org.hamcrest:hamcrest-integration:1.1
     |    --- org.hamcrest:hamcrest-core:1.1 -> 1.3
     +--- com.android.support.test.espresso:espresso-idling-resource:2.1
     +--- org.hamcrest:hamcrest-library:1.1
     |    --- org.hamcrest:hamcrest-core:1.1 -> 1.3
     +--- javax.inject:javax.inject:1
     +--- com.google.code.findbugs:jsr305:2.0.1
     +--- com.android.support.test:runner:0.2 -> 0.4 ()
     +--- javax.annotation:javax.annotation-api:1.2
     --- org.hamcrest:hamcrest-core:1.1 -> 1.3

Force

force强制设置某个模块的版本。

  
configurations.all {
   resolutionStrategy {
       force 'org.hamcrest:hamcrest-core:1.3'
   }
}
dependencies {
   androidTestCompile('com.android.support.test:runner:0.2')
   androidTestCompile('com.android.support.test:rules:0.2')
   androidTestCompile('com.android.support.test.espresso:espresso-core:2.1')
}

可以看到，原本对hamcrest-core 1.1的依赖，全部变成了1.3。

  
+--- com.android.support.test:runner:0.2
|    +--- junit:junit-dep:4.10
|    |    --- org.hamcrest:hamcrest-core:1.1 -> 1.3
|    +--- com.android.support.test:exposed-instrumentation-api-publish:0.2
|    --- com.android.support:support-annotations:22.0.0
+--- com.android.support.test:rules:0.2
|    --- com.android.support.test:runner:0.2 ()
--- com.android.support.test.espresso:espresso-core:2.1
     +--- com.android.support.test:rules:0.2 ()
     +--- com.squareup:javawriter:2.1.1
     +--- org.hamcrest:hamcrest-integration:1.1
     |    --- org.hamcrest:hamcrest-core:1.1 -> 1.3
     +--- com.android.support.test.espresso:espresso-idling-resource:2.1
     +--- org.hamcrest:hamcrest-library:1.1
     |    --- org.hamcrest:hamcrest-core:1.1 -> 1.3
     +--- javax.inject:javax.inject:1
     +--- com.google.code.findbugs:jsr305:2.0.1
     +--- com.android.support.test:runner:0.2 ()
     +--- javax.annotation:javax.annotation-api:1.2
     --- org.hamcrest:hamcrest-core:1.1 -> 1.3

Exclude

Exclude可以设置不编译指定的模块

  
configurations {
   all.exclude group: 'org.hamcrest', module: 'hamcrest-core'
}
dependencies {
   androidTestCompile('com.android.support.test:runner:0.2')
   androidTestCompile('com.android.support.test:rules:0.2')
   androidTestCompile('com.android.support.test.espresso:espresso-core:2.1')
}

  
+--- com.android.support.test:runner:0.2
|    +--- junit:junit-dep:4.10
|    +--- com.android.support.test:exposed-instrumentation-api-publish:0.2
|    --- com.android.support:support-annotations:22.0.0
+--- com.android.support.test:rules:0.2
|    --- com.android.support.test:runner:0.2 ()
--- com.android.support.test.espresso:espresso-core:2.1
     +--- com.android.support.test:rules:0.2 ()
     +--- com.squareup:javawriter:2.1.1
     +--- org.hamcrest:hamcrest-integration:1.1
     +--- com.android.support.test.espresso:espresso-idling-resource:2.1
     +--- org.hamcrest:hamcrest-library:1.1
     +--- javax.inject:javax.inject:1
     +--- com.google.code.findbugs:jsr305:2.0.1
     +--- com.android.support.test:runner:0.2 ()
     --- javax.annotation:javax.annotation-api:1.2

单独使用group或module参数

exclude后的参数有group和module，可以分别单独使用，会排除所有匹配项。例如下面的脚本匹配了所有的group为’com.android.support.test’的模块。

  
configurations {
   all.exclude group: 'com.android.support.test'
}
dependencies {
   androidTestCompile('com.android.support.test:runner:0.2')
   androidTestCompile('com.android.support.test:rules:0.2')
   androidTestCompile('com.android.support.test.espresso:espresso-core:2.1')
}

  
--- com.android.support.test.espresso:espresso-core:2.1
     +--- com.squareup:javawriter:2.1.1
     +--- org.hamcrest:hamcrest-integration:1.1
     |    --- org.hamcrest:hamcrest-core:1.1
     +--- com.android.support.test.espresso:espresso-idling-resource:2.1
     +--- org.hamcrest:hamcrest-library:1.1
     |    --- org.hamcrest:hamcrest-core:1.1
     +--- javax.inject:javax.inject:1
     +--- com.google.code.findbugs:jsr305:2.0.1
     +--- javax.annotation:javax.annotation-api:1.2
     --- org.hamcrest:hamcrest-core:1.1

单独给某个模块指定exclude

  
dependencies {
   androidTestCompile('com.android.support.test:runner:0.2')
   androidTestCompile('com.android.support.test:rules:0.2')
   androidTestCompile('com.android.support.test.espresso:espresso-core:2.1') {
       exclude group: 'org.hamcrest'
   }
}

  
+--- com.android.support.test:runner:0.2
|    +--- junit:junit-dep:4.10
|    |    --- org.hamcrest:hamcrest-core:1.1
|    +--- com.android.support.test:exposed-instrumentation-api-publish:0.2
|    --- com.android.support:support-annotations:22.0.0
+--- com.android.support.test:rules:0.2
|    --- com.android.support.test:runner:0.2 ()
--- com.android.support.test.espresso:espresso-core:2.1
     +--- com.android.support.test:rules:0.2 ()
     +--- com.squareup:javawriter:2.1.1
     +--- com.android.support.test.espresso:espresso-idling-resource:2.1
     +--- javax.inject:javax.inject:1
     +--- com.google.code.findbugs:jsr305:2.0.1
     +--- com.android.support.test:runner:0.2 ()
     --- javax.annotation:javax.annotation-api:1.2

不同配置下的版本冲突

同样的配置下的版本冲突，会自动使用最新版；而不同配置下的版本冲突，gradle同步时会直接报错。可使用exclude、force解决冲突。

例如compile 'com.android.support:appcompat-v7:23.1.1'，和androidTestCompile 'com.android.support.test.espresso:espresso-core:2.1'，所依赖的com.android.support:support-annotations版本不同，就会导致冲突。

  
dependencies {
   compile 'com.android.support:appcompat-v7:23.1.1'
   androidTestCompile('com.android.support.test:runner:0.2')
   androidTestCompile('com.android.support.test:rules:0.2')
   androidTestCompile('com.android.support.test.espresso:espresso-core:2.1')
}

gradle同步时会提示

  
Warning:Conflict with dependency 'com.android.support:support-annotations'. Resolved versions for app and test app differ.

执行dependencies会提示

  
FAILURE: Build failed with an exception.
 What went wrong:
A problem occurred configuring project ':app'.
> Conflict with dependency 'com.android.support:support-annotations'. Resolved versions for app and test app differ.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
BUILD FAILED

不兼容

虽然可以通过force、exclude等方式避免依赖项版本冲突，使得grade同步成功，但是并不能代表编译时没有问题。由于不同版本可能不完全兼容，于是会出现各种奇怪的报错。已知的解决思路是更改包的版本、尝试强制使用不同版本的依赖项，找到可兼容的依赖组合。

报错例如：

  
com.android.dex.DexException: Multiple dex files define Lorg/hamcrest/MatcherAssert;
at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:596)
at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:554)
at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:535)
at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:171)
at com.android.dx.merge.DexMerger.merge(DexMerger.java:189)
at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:454)
at com.android.dx.command.dexer.Main.runMonoDex(Main.java:303)
at com.android.dx.command.dexer.Main.run(Main.java:246)
at com.android.dx.command.dexer.Main.main(Main.java:215)
at com.android.dx.command.Main.main(Main.java:106)
Error:Execution failed for task ':app:dexDebugAndroidTest'.
> com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process 'command '/Library/Java/JavaVirtualMachines/jdk1.8.0_40.jdk/Contents/Home/bin/java'' finished with non-zero exit value 2
BUILD FAILED

又例如Android执行Espresso单元测试时出现：

  
Running tests
Test running started
java.lang.NoSuchMethodError: org.hamcrest.core.AnyOf.anyOf
at org.hamcrest.Matchers.anyOf(Matchers.java:87)
at android.support.test.espresso.Espresso.<clinit>(Espresso.java:158)
at com.jzj1993.unittest.test.MainActivityEspressoTest.sayHello(MainActivityEspressoTest.java:28)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at org.junit.runners.model.FrameworkMethod$1</span><span class="pun">.</span><span class="pln">runReflectiveCall</span><span class="pun">(</span><span class="typ">FrameworkMethod</span><span class="pun">.</span><span class="pln">java</span><span class="pun">:</span><span class="lit">45</span><span class="pun">)</span></code></li><li style="list-style-type: none; padding-left: 0px;" class="L9"><code><span class="pln">at org</span><span class="pun">.</span><span class="pln">junit</span><span class="pun">.</span><span class="kwd">internal</span><span class="pun">.</span><span class="pln">runners</span><span class="pun">.</span><span class="pln">model</span><span class="pun">.</span><span class="typ">ReflectiveCallable</span><span class="pun">.</span><span class="pln">run</span><span class="pun">(</span><span class="typ">ReflectiveCallable</span><span class="pun">.</span><span class="pln">java</span><span class="pun">:</span><span class="lit">15</span><span class="pun">)</span></code></li><li style="list-style-type: none; padding-left: 0px;" class="L0"><code><span class="pln">at org</span><span class="pun">.</span><span class="pln">junit</span><span class="pun">.</span><span class="pln">runners</span><span class="pun">.</span><span class="pln">model</span><span class="pun">.</span><span class="typ">FrameworkMethod</span><span class="pun">.</span><span class="pln">invokeExplosively</span><span class="pun">(</span><span class="typ">FrameworkMethod</span><span class="pun">.</span><span class="pln">java</span><span class="pun">:</span><span class="lit">42</span><span class="pun">)</span></code></li><li style="list-style-type: none; padding-left: 0px;" class="L1"><code><span class="pln">at org</span><span class="pun">.</span><span class="pln">junit</span><span class="pun">.</span><span class="kwd">internal</span><span class="pun">.</span><span class="pln">runners</span><span class="pun">.</span><span class="pln">statements</span><span class="pun">.</span><span class="typ">InvokeMethod</span><span class="pun">.</span><span class="pln">evaluate</span><span class="pun">(</span><span class="typ">InvokeMethod</span><span class="pun">.</span><span class="pln">java</span><span class="pun">:</span><span class="lit">20</span><span class="pun">)</span></code></li><li style="list-style-type: none; padding-left: 0px;" class="L2"><code><span class="pln">at android</span><span class="pun">.</span><span class="pln">support</span><span class="pun">.</span><span class="pln">test</span><span class="pun">.</span><span class="kwd">internal</span><span class="pun">.</span><span class="pln">statement</span><span class="pun">.</span><span class="typ">UiThreadStatement</span><span class="pun">.</span><span class="pln">evaluate</span><span class="pun">(</span><span class="typ">UiThreadStatement</span><span class="pun">.</span><span class="pln">java</span><span class="pun">:</span><span class="lit">55</span><span class="pun">)</span></code></li><li style="list-style-type: none; padding-left: 0px;" class="L3"><code><span class="pln">at android</span><span class="pun">.</span><span class="pln">support</span><span class="pun">.</span><span class="pln">test</span><span class="pun">.</span><span class="pln">rule</span><span class="pun">.</span><span class="typ">ActivityTestRule$ActivityStatement.evaluate(ActivityTestRule.java:257)
at org.junit.rules.RunRules.evaluate(RunRules.java:18)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
at org.junit.runners.ParentRunner$3</span><span class="pun">.</span><span class="pln">run</span><span class="pun">(</span><span class="typ">ParentRunner</span><span class="pun">.</span><span class="pln">java</span><span class="pun">:</span><span class="lit">231</span><span class="pun">)</span></code></li><li style="list-style-type: none; padding-left: 0px;" class="L9"><code><span class="pln">at org</span><span class="pun">.</span><span class="pln">junit</span><span class="pun">.</span><span class="pln">runners</span><span class="pun">.</span><span class="typ">ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000</span><span class="pun">(</span><span class="typ">ParentRunner</span><span class="pun">.</span><span class="pln">java</span><span class="pun">:</span><span class="lit">50</span><span class="pun">)</span></code></li><li style="list-style-type: none; padding-left: 0px;" class="L2"><code><span class="pln">at org</span><span class="pun">.</span><span class="pln">junit</span><span class="pun">.</span><span class="pln">runners</span><span class="pun">.</span><span class="typ">ParentRunner$2.evaluate(ParentRunner.java:222)
at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.junit.runners.Suite.runChild(Suite.java:128)
at org.junit.runners.Suite.runChild(Suite.java:24)
at org.junit.runners.ParentRunner$3</span><span class="pun">.</span><span class="pln">run</span><span class="pun">(</span><span class="typ">ParentRunner</span><span class="pun">.</span><span class="pln">java</span><span class="pun">:</span><span class="lit">231</span><span class="pun">)</span></code></li><li style="list-style-type: none; padding-left: 0px;" class="L7"><code><span class="pln">at org</span><span class="pun">.</span><span class="pln">junit</span><span class="pun">.</span><span class="pln">runners</span><span class="pun">.</span><span class="typ">ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000</span><span class="pun">(</span><span class="typ">ParentRunner</span><span class="pun">.</span><span class="pln">java</span><span class="pun">:</span><span class="lit">50</span><span class="pun">)</span></code></li><li style="list-style-type: none; padding-left: 0px;" class="L0"><code><span class="pln">at org</span><span class="pun">.</span><span class="pln">junit</span><span class="pun">.</span><span class="pln">runners</span><span class="pun">.</span><span class="typ">ParentRunner$2.evaluate(ParentRunner.java:222)
at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
at org.junit.runner.JUnitCore.run(JUnitCore.java:136)
at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:54)
at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:228)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1701)
Finish

参考资料与扩展阅读

https://docs.gradle.org/current/userguide/dependency_management.html
http://www.concretepage.com/build-tools/gradle/gradle-exclude-transitive-dependency-example