Gradle 库依赖关系的管理

查看库依赖关系

---

列出指定module的依赖关系

./gradlew -q moduleName:dependencies > outfile.txt

列出多个指定module的依赖关系

./gradlew -q dependencies moduleName1:dependencies moduleName2:dependencies > outfile.txt

过滤依赖信息

# 只看通过implementation依赖的库关系
./gradlew -q moduleName:dependencies --configuration implementation > outfile.txt

其中moduleName为Module的名字，如app；
outfile.txt 是任务执行结果输出的文件，由于这些命令输出的内容比较多，在终端查看和搜索都不是很方便，因此建议将结果输出到文件。

举个例子：
在终端（控制台）执行：

./gradlew -q tools:dependencies > ./build/deps_tools.txt

部分结果如下：

+--- com.google.zxing:core:3.3.0
+--- io.reactivex.rxjava2:rxandroid:2.0.1
|    \--- io.reactivex.rxjava2:rxjava:2.0.1 -> 2.1.5
|         \--- org.reactivestreams:reactive-streams:1.0.1
+--- io.reactivex.rxjava2:rxjava:2.1.5 (*)
+--- com.squareup.okhttp3:okhttp:3.9.0
|    \--- com.squareup.okio:okio:1.13.0
+--- com.squareup.okhttp3:logging-interceptor:3.9.0
|    \--- com.squareup.okhttp3:okhttp:3.9.0 (*)
+--- com.android.support:support-annotations:27.1.1
+--- com.android.support:appcompat-v7:27.1.1
|    +--- com.android.support:support-annotations:27.1.1
|    +--- com.android.support:support-core-utils:27.1.1
|    |    +--- com.android.support:support-annotations:27.1.1
|    |    \--- com.android.support:support-compat:27.1.1
|    |         +--- com.android.support:support-annotations:27.1.1
|    |         \--- android.arch.lifecycle:runtime:1.1.0
|    |              +--- android.arch.lifecycle:common:1.1.0
|    |              \--- android.arch.core:common:1.1.0
|    +--- com.android.support:support-fragment:27.1.1
|    |    +--- com.android.support:support-compat:27.1.1 (*)
|    |    +--- com.android.support:support-core-ui:27.1.1
|    |    |    +--- com.android.support:support-annotations:27.1.1
|    |    |    +--- com.android.support:support-compat:27.1.1 (*)
|    |    |    \--- com.android.support:support-core-utils:27.1.1 (*)
|    |    +--- com.android.support:support-core-utils:27.1.1 (*)
|    |    +--- com.android.support:support-annotations:27.1.1
|    |    +--- android.arch.lifecycle:livedata-core:1.1.0
|    |    |    +--- android.arch.lifecycle:common:1.1.0
|    |    |    +--- android.arch.core:common:1.1.0
|    |    |    \--- android.arch.core:runtime:1.1.0
|    |    |         \--- android.arch.core:common:1.1.0
|    |    \--- android.arch.lifecycle:viewmodel:1.1.0
|    +--- com.android.support:support-vector-drawable:27.1.1
|    |    +--- com.android.support:support-annotations:27.1.1
|    |    \--- com.android.support:support-compat:27.1.1 (*)
|    \--- com.android.support:animated-vector-drawable:27.1.1
|         +--- com.android.support:support-vector-drawable:27.1.1 (*)
|         \--- com.android.support:support-core-ui:27.1.1 (*)
+--- com.orhanobut:logger:2.1.1
+--- com.github.bumptech.glide:glide:4.2.0
|    +--- com.github.bumptech.glide:gifdecoder:4.2.0
|    |    \--- com.android.support:support-annotations:26.0.2 -> 27.1.1
|    +--- com.github.bumptech.glide:disklrucache:4.2.0
|    \--- com.github.bumptech.glide:annotations:4.2.0
+--- com.alibaba:arouter-api:1.2.4
|    +--- com.alibaba:arouter-annotation:1.0.4
|    \--- com.android.support:support-v4:25.2.0
|         +--- com.android.support:support-compat:25.2.0 -> 27.1.1 (*)
|         +--- com.android.support:support-media-compat:25.2.0
|         |    +--- com.android.support:support-annotations:25.2.0 -> 27.1.1
|         |    \--- com.android.support:support-compat:25.2.0 -> 27.1.1 (*)
|         +--- com.android.support:support-core-utils:25.2.0 -> 27.1.1 (*)
|         +--- com.android.support:support-core-ui:25.2.0 -> 27.1.1 (*)
|         \--- com.android.support:support-fragment:25.2.0 -> 27.1.1 (*)
+--- org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.2.41
|    \--- org.jetbrains.kotlin:kotlin-stdlib:1.2.41
|         \--- org.jetbrains:annotations:13.0
\--- org.jetbrains.anko:anko:0.10.4
     +--- org.jetbrains.kotlin:kotlin-stdlib:1.1.0 -> 1.2.41 (*)
     +--- org.jetbrains.anko:anko-commons:0.10.4
     |    \--- org.jetbrains.kotlin:kotlin-stdlib:1.1.0 -> 1.2.41 (*)
     +--- org.jetbrains.anko:anko-coroutines:0.10.4
     |    +--- org.jetbrains.kotlin:kotlin-stdlib:1.1.0 -> 1.2.41 (*)
     |    \--- org.jetbrains.kotlinx:kotlinx-coroutines-android:0.15
     |         +--- org.jetbrains.kotlinx:kotlinx-coroutines-core:0.15
     |         |    \--- org.jetbrains.kotlin:kotlin-stdlib:1.1.2 -> 1.2.41 (*)
     |         \--- org.jetbrains.kotlin:kotlin-stdlib:1.1.2 -> 1.2.41 (*)
     +--- org.jetbrains.anko:anko-sqlite:0.10.4
     |    +--- org.jetbrains.kotlin:kotlin-stdlib:1.1.0 -> 1.2.41 (*)
     |    \--- org.jetbrains.anko:anko-commons:0.10.4 (*)
     +--- org.jetbrains.anko:anko-sdk25:0.10.4
     |    +--- org.jetbrains.kotlin:kotlin-stdlib:1.1.0 -> 1.2.41 (*)
     |    \--- org.jetbrains.anko:anko-commons:0.10.4 (*)
     +--- org.jetbrains.anko:anko-sdk25-coroutines:0.10.4
     |    +--- org.jetbrains.kotlin:kotlin-stdlib:1.1.0 -> 1.2.41 (*)
     |    +--- org.jetbrains.kotlinx:kotlinx-coroutines-android:0.15 (*)
     |    \--- org.jetbrains.anko:anko-commons:0.10.4 (*)
     +--- org.jetbrains.anko:anko-appcompat-v7:0.10.4
     |    +--- org.jetbrains.kotlin:kotlin-stdlib:1.1.0 -> 1.2.41 (*)
     |    +--- org.jetbrains.anko:anko-support-v4:0.10.4
     |    |    +--- org.jetbrains.kotlin:kotlin-stdlib:1.1.0 -> 1.2.41 (*)
     |    |    +--- org.jetbrains.anko:anko-commons:0.10.4 (*)
     |    |    \--- org.jetbrains.anko:anko-support-v4-commons:0.10.4
     |    |         +--- org.jetbrains.kotlin:kotlin-stdlib:1.1.0 -> 1.2.41 (*)
     |    |         \--- org.jetbrains.anko:anko-commons:0.10.4 (*)
     |    \--- org.jetbrains.anko:anko-appcompat-v7-commons:0.10.4
     |         +--- org.jetbrains.kotlin:kotlin-stdlib:1.1.0 -> 1.2.41 (*)
     |         \--- org.jetbrains.anko:anko-support-v4-commons:0.10.4 (*)
     \--- org.jetbrains.anko:anko-appcompat-v7-coroutines:0.10.4
          +--- org.jetbrains.kotlin:kotlin-stdlib:1.1.0 -> 1.2.41 (*)
          +--- org.jetbrains.kotlinx:kotlinx-coroutines-android:0.15 (*)
          +--- org.jetbrains.anko:anko-support-v4-commons:0.10.4 (*)
          \--- org.jetbrains.anko:anko-appcompat-v7-commons:0.10.4 (*)

其中 * 表示 之前已经列出过这个依赖，就不会再下载了

其中 -> 表示 低版本 -> 高版本，会强制依赖项目中版本高的依赖库

解决依赖冲突

依赖冲突一般有两种，一个是版本冲突，一个是重复依赖。

解决依赖冲突的原则就是最终确定依赖一个固定的版本的库。

可以用多种方法解决依赖冲突：

transitive

---

依赖传递指的是:如果A依赖于B，则A也同样依赖B所依赖的库。
可以通过transitive来控制
统一指定transitive：

   //建议不要这么做，因为一旦关闭所有的依赖传递，你很可能不清楚具体依赖什么库，而导致出错
   configurations.all {
        transitive = false
    }

单独排除关闭某个库的依赖传递：

 implementation("com.android.support:support-compat:27.1.1"){
        transitive = false
    }

force

gradle还可以强制使用某个版本的依赖

比如项目中有的库使用了低版本的lifecyle库或者support库，这个时候引入最新的Lifecycle库就会出现版本冲突，可以强制指定版本：

configurations.all {
        resolutionStrategy {
            def lifecycle_version = "1.1.1"
            force "android.arch.lifecycle:extensions:$lifecycle_version"
            force "android.arch.lifecycle:runtime:$lifecycle_version"
            force "android.arch.lifecycle:compiler:$lifecycle_version"
        }
    }

exclude

当出现依赖冲突的时候，比如重复依赖，可以排除掉多余的依赖，或者排除低版本的依赖。

  //排除RecyclerView依赖库
  configurations.all {
        exclude group: 'com.android.support', module: 'recyclerview-v7'
    }

  //排除所有support库包括v7，v4等
    configurations.all {
        exclude group: 'com.android.support'
    }

    //单独排除依赖
    implementation("com.google.dagger:dagger:2.15") {
        exclude group: 'javax.inject', module: 'javax.inject'
    }

参考文档

http://www.paincker.com/gradle-dependencies#i-5