深海游弋的鱼 – 默默的点滴

Shared Preferences的分析

The SharedPreferences class provides a general framework that allows you to save and retrieve persistent key-value pairs of primitive data types. You can use SharedPreferences to save any primitive data: booleans, floats, ints, longs, and strings. This data will persist across user sessions (even if your application is killed).

调用getSharedPreferences()获取对应的的文件，该函数实现功能如下：

//Context类静态数据集合，以键值对保存了所有读取该xml文件后所形成的数据集合

private static final HashMap<File, SharedPreferencesImpl> sSharedPrefs =new HashMap<File, SharedPreferencesImpl>();

1	private static final HashMap<File, SharedPreferencesImpl> sSharedPrefs =new HashMap<File, SharedPreferencesImpl>();

可以看到他有一个Map，而针对SharedPreferencesImpl里面，由会有map，这样也就可以证明，为什么SharedPreference被广泛使用了。他在普通时刻，内容是从内存里面直接读取的，只有在第一次启动时，是IO操作。

2. apply()和commit()的区别

/** boolean commit();的注释如下：

* Commit your preferences changes back from this Editor to the
* {@link SharedPreferences} object it is editing. This atomically
* performs the requested modifications, replacing whatever is currently
* in the SharedPreferences.
*
*

Note that when two editors are modifying preferences at the same
* time, the last one to call commit wins.
*
*

If you don't care about the return value and you're
* using this from your application's main thread, consider
* using {@link #apply} instead. 如果你不考虑返回值，你在主线程中已经使用commit，那么你可以考虑替换使用apply
*
* @return Returns true if the new values were successfully written
* to persistent storage.
*/

* Commit your preferences changes back from this Editor to the

* {@link SharedPreferences} object it is editing. This atomically

* performs the requested modifications, replacing whatever is currently

* in the SharedPreferences.

Note that when two editors are modifying preferences at the same

* time, the last one to call commit wins.

If you don't care about the return value and you're

* using this from your application's main thread, consider

* using {@link #apply} instead. 如果你不考虑返回值，你在主线程中已经使用commit，那么你可以考虑替换使用apply

* @return Returns true if the new values were successfully written

* to persistent storage.

apply方法的注释：

*Unlike {@link #commit}, which writes its preferences out
* to persistent storage synchronously, {@link #apply}
* commits its changes to the in-memory
* {@link SharedPreferences} immediately but starts an
* asynchronous commit to disk and you won't be notified of
* any failures. If another editor on this
* {@link SharedPreferences} does a regular {@link #commit}
* while a {@link #apply} is still outstanding, the
* {@link #commit} will block until all async commits are
* completed as well as the commit itself.

*Unlike {@link #commit}, which writes its preferences out

* to persistent storage synchronously, {@link #apply}

* commits its changes to the in-memory

* {@link SharedPreferences} immediately but starts an

* asynchronous commit to disk and you won't be notified of

* any failures. If another editor on this

* {@link SharedPreferences} does a regular {@link #commit}

* while a {@link #apply} is still outstanding, the

* {@link #commit} will block until all async commits are

* completed as well as the commit itself.

apply不同于commit，commit是同步的去更改硬盘上的东西，而apply是先直接更改内存中的，然后异步的去更改应硬盘中的内容。

不用去担心线程安全问题，因为如果一个其他的线程去commit，而刚好有一个还没有完成的apply，commit会被阻塞到异步线程提交完成。

*
*

As {@link SharedPreferences} instances are singletons within
* a process, it's safe to replace any instance of {@link #commit} with
* {@link #apply} if you were already ignoring the return value. 如果你真的可以忽略返回值，恰好SharedPreferences又是单例模式的，那就可以安全的用apply来替换commit
*
*

You don't need to worry about Android component
* lifecycles and their interaction with apply()
* writing to disk. The framework makes sure in-flight disk
* writes from apply() complete before switching
* states. 也不需要去关心android组件的声明周期。 框架会保证完成所有apply之后，才切换状态。

As {@link SharedPreferences} instances are singletons within

* a process, it's safe to replace any instance of {@link #commit} with

* {@link #apply} if you were already ignoring the return value. 如果你真的可以忽略返回值，恰好SharedPreferences又是单例模式的，那就可以安全的用apply来替换commit

You don't need to worry about Android component

* lifecycles and their interaction with apply()

* writing to disk. The framework makes sure in-flight disk

* writes from apply() complete before switching

* states. 也不需要去关心android组件的声明周期。框架会保证完成所有apply之后，才切换状态。

参考链接

Shared Preferences的分析

Android Studio中的productFlavors指定默认编译执行的任务

Android Studio中指定了productFlavors如下：

    productFlavors {
        /*日常*/
        Daily {
        }
        /*线上*/
        Online {
        }
        /*预发*/
        Advance {
        }
    }

productFlavors {

/*日常*/

Daily {

}

/*线上*/

Online {

}

/*预发*/

Advance {

}

整个的build.gradle里面的内容如下：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.2"

    defaultConfig {
        applicationId "com.my.myapplication"
        minSdkVersion 15
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

    productFlavors {
        /*日常*/
        Daily {
        }
        /*线上*/
        Online {
        }
        /*预发*/
        Advance {
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.2.1'
}

apply plugin: 'com.android.application'

android {

compileSdkVersion 23

buildToolsVersion "23.0.2"

defaultConfig {

applicationId "com.my.myapplication"

minSdkVersion 15

targetSdkVersion 23

versionCode 1

versionName "1.0"

}

buildTypes {

release {

minifyEnabled false

proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

}

productFlavors {

/*日常*/

Daily {

}

/*线上*/

Online {

}

/*预发*/

Advance {

}

dependencies {

compile fileTree(dir: 'libs', include: ['*.jar'])

testCompile 'junit:junit:4.12'

compile 'com.android.support:appcompat-v7:23.2.1'

}

但是这个时候我们点击Android Studio的调试按钮的时候，不知道究竟是使用哪个Flavors来编译，比如在Android Studio 1.5的时候,是按照从上到下的顺序处理的，默认是使用排在第一个的Daily,而到了Android Studio 2.1 Preview 5版本，却变成了按照字母排序，结果变成了默认编译Advance 。

网上搜索了一下，找到如下解决方法：

选择"Build Variant",然后在出现的窗口中选择其中一个选项作为默认的编译，运行选项即可。

BuildVariantSel

参考链接

Gradle Build only a flavour

Android Studio(Gradle)解决库依赖冲突问题

最近在调整代码的时候，出现如下问题：

Cause: com.android.dex.DexException: Multiple dex files define Landroid/support/annotation/AnimRes;
    UNEXPECTED TOP-LEVEL EXCEPTION:
com.android.dex.DexException: Multiple dex files define Landroid/support/annotation/AnimRes;
        at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:579)
        at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:535)
        at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:517)
        at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:164)
        at com.android.dx.merge.DexMerger.merge(DexMerger.java:188)
        at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:504)
        at com.android.dx.command.dexer.Main.runMonoDex(Main.java:334)
        at com.android.dx.command.dexer.Main.run(Main.java:277)
        at com.android.dx.command.dexer.Main.main(Main.java:245)
        at com.android.dx.command.Main.main(Main.java:106)

Cause: com.android.dex.DexException: Multiple dex files define Landroid/support/annotation/AnimRes;

UNEXPECTED TOP-LEVEL EXCEPTION:

com.android.dex.DexException: Multiple dex files define Landroid/support/annotation/AnimRes;

at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:579)

at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:535)

at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:517)

at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:164)

at com.android.dx.merge.DexMerger.merge(DexMerger.java:188)

at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:504)

at com.android.dx.command.dexer.Main.runMonoDex(Main.java:334)

at com.android.dx.command.dexer.Main.run(Main.java:277)

at com.android.dx.command.dexer.Main.main(Main.java:245)

at com.android.dx.command.Main.main(Main.java:106)

网上查询了一下，找到如下的解决方法：

我们常常用gradle.build文件导入依赖库，但是有时候库依赖会发生版本冲突或多个模块依赖同一个库的情况。

这就引出两个问题，如下：

版本冲突时，Gradle会下载多个版本的依赖库吗？
当多个模块依赖同一个库时，每个模块都会去下载该依赖库吗？
为解决这疑问，接下来我们在Android Studio用Gradle举个例子：
gradle.build依赖部分的配置：

dependencies {
    compile 'com.android.support:appcompat-v7:22.2.1'
    compile ('com.android.support:design:22.2.1')
    compile 'com.shamanland:fonticon:0.1.8'
    androidTestCompile 'com.android.support:support-annotations:22.2.1'
    androidTestCompile 'com.android.support.test:runner:0.3'
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2')
}

dependencies {

compile 'com.android.support:appcompat-v7:22.2.1'

compile ('com.android.support:design:22.2.1')

compile 'com.shamanland:fonticon:0.1.8'

androidTestCompile 'com.android.support:support-annotations:22.2.1'

androidTestCompile 'com.android.support.test:runner:0.3'

androidTestCompile('com.android.support.test.espresso:espresso-core:2.2')

}

在文件目录下或Android Studio的Terminal下敲gradlew -q app:dependencies 命令，便有以下输出：

_debugAndroidTestApk - ## Internal use, do not manually configure ##
+--- com.android.support:support-annotations:22.2.1
+--- com.android.support.test:runner:0.3
|    +--- com.android.support.test:exposed-instrumentation-api-publish:0.3
|    +--- junit:junit:4.12
|    |    \--- org.hamcrest:hamcrest-core:1.3
|    \--- com.android.support:support-annotations:22.2.0 -> 22.2.1
\--- com.android.support.test.espresso:espresso-core:2.2
     +--- com.android.support.test.espresso:espresso-idling-resource:2.2
     +--- com.squareup:javawriter:2.1.1
     +--- javax.inject:javax.inject:1
     +--- org.hamcrest:hamcrest-library:1.3
     |    \--- org.hamcrest:hamcrest-core:1.3
     +--- com.android.support.test:rules:0.3
     |    \--- com.android.support.test:runner:0.3 (*)
     +--- org.hamcrest:hamcrest-integration:1.3
     |    \--- org.hamcrest:hamcrest-library:1.3 (*)
     +--- com.google.code.findbugs:jsr305:2.0.1
     +--- javax.annotation:javax.annotation-api:1.2
     \--- com.android.support.test:runner:0.3 (*)

_debugAndroidTestCompile - ## Internal use, do not manually configure ##
+--- com.android.support:support-annotations:22.2.1
+--- com.android.support.test:runner:0.3
|    +--- com.android.support.test:exposed-instrumentation-api-publish:0.3
|    +--- junit:junit:4.12
|    |    \--- org.hamcrest:hamcrest-core:1.3
|    \--- com.android.support:support-annotations:22.2.0 -> 22.2.1
\--- com.android.support.test.espresso:espresso-core:2.2
     +--- com.android.support.test.espresso:espresso-idling-resource:2.2
     +--- com.squareup:javawriter:2.1.1
     +--- javax.inject:javax.inject:1
     +--- org.hamcrest:hamcrest-library:1.3
     |    \--- org.hamcrest:hamcrest-core:1.3
     +--- com.android.support.test:rules:0.3
     |    \--- com.android.support.test:runner:0.3 (*)
     +--- org.hamcrest:hamcrest-integration:1.3
     |    \--- org.hamcrest:hamcrest-library:1.3 (*)
     +--- com.google.code.findbugs:jsr305:2.0.1
     +--- javax.annotation:javax.annotation-api:1.2
     \--- com.android.support.test:runner:0.3 (*)

_debugApk - ## Internal use, do not manually configure ##
+--- com.android.support:multidex:1.0.1
+--- com.android.support:appcompat-v7:22.2.1
|    \--- com.android.support:support-v4:22.2.1
|         \--- com.android.support:support-annotations:22.2.1
+--- com.android.support:design:22.2.1
|    +--- com.android.support:appcompat-v7:22.2.1 (*)
|    \--- com.android.support:support-v4:22.2.1 (*)
\--- com.shamanland:fonticon:0.1.8

_debugCompile - ## Internal use, do not manually configure ##
+--- com.android.support:multidex:1.0.1
+--- com.android.support:appcompat-v7:22.2.1
|    \--- com.android.support:support-v4:22.2.1
|         \--- com.android.support:support-annotations:22.2.1
+--- com.android.support:design:22.2.1
|    +--- com.android.support:appcompat-v7:22.2.1 (*)
|    \--- com.android.support:support-v4:22.2.1 (*)
\--- com.shamanland:fonticon:0.1.8

_debugUnitTestApk - ## Internal use, do not manually configure ##
No dependencies

_debugUnitTestCompile - ## Internal use, do not manually configure ##
No dependencies

_releaseApk - ## Internal use, do not manually configure ##
+--- com.android.support:multidex:1.0.1
+--- com.android.support:appcompat-v7:22.2.1
|    \--- com.android.support:support-v4:22.2.1
|         \--- com.android.support:support-annotations:22.2.1
+--- com.android.support:design:22.2.1
|    +--- com.android.support:appcompat-v7:22.2.1 (*)
|    \--- com.android.support:support-v4:22.2.1 (*)
\--- com.shamanland:fonticon:0.1.8

_releaseCompile - ## Internal use, do not manually configure ##
+--- com.android.support:multidex:1.0.1
+--- com.android.support:appcompat-v7:22.2.1
|    \--- com.android.support:support-v4:22.2.1
|         \--- com.android.support:support-annotations:22.2.1
+--- com.android.support:design:22.2.1
|    +--- com.android.support:appcompat-v7:22.2.1 (*)
|    \--- com.android.support:support-v4:22.2.1 (*)
\--- com.shamanland:fonticon:0.1.8

_releaseUnitTestApk - ## Internal use, do not manually configure ##
No dependencies

_releaseUnitTestCompile - ## Internal use, do not manually configure ##
No dependencies

androidJacocoAgent - The Jacoco agent to use to get coverage data.
\--- org.jacoco:org.jacoco.agent:0.7.4.201502262128

androidJacocoAnt - The Jacoco ant tasks to use to get execute Gradle tasks.
\--- org.jacoco:org.jacoco.ant:0.7.4.201502262128
     +--- org.jacoco:org.jacoco.core:0.7.4.201502262128
     |    \--- org.ow2.asm:asm-debug-all:5.0.1
     +--- org.jacoco:org.jacoco.report:0.7.4.201502262128
     |    +--- org.jacoco:org.jacoco.core:0.7.4.201502262128 (*)
     |    \--- org.ow2.asm:asm-debug-all:5.0.1
     \--- org.jacoco:org.jacoco.agent:0.7.4.201502262128

androidTestApk - Classpath packaged with the compiled 'androidTest' classes.
No dependencies

androidTestCompile - Classpath for compiling the androidTest sources.
+--- com.android.support:support-annotations:22.2.1
+--- com.android.support.test:runner:0.3
|    +--- com.android.support.test:exposed-instrumentation-api-publish:0.3
|    +--- junit:junit:4.12
|    |    \--- org.hamcrest:hamcrest-core:1.3
|    \--- com.android.support:support-annotations:22.2.0 -> 22.2.1
\--- com.android.support.test.espresso:espresso-core:2.2
     +--- com.android.support.test.espresso:espresso-idling-resource:2.2
     +--- com.squareup:javawriter:2.1.1
     +--- javax.inject:javax.inject:1
     +--- org.hamcrest:hamcrest-library:1.3
     |    \--- org.hamcrest:hamcrest-core:1.3
     +--- com.android.support.test:rules:0.3
     |    \--- com.android.support.test:runner:0.3 (*)
     +--- org.hamcrest:hamcrest-integration:1.3
     |    \--- org.hamcrest:hamcrest-library:1.3 (*)
     +--- com.google.code.findbugs:jsr305:2.0.1
     +--- javax.annotation:javax.annotation-api:1.2
     \--- com.android.support.test:runner:0.3 (*)

androidTestProvided - Classpath for only compiling the androidTest sources.
No dependencies

androidTestWearApp - Link to a wear app to embed for object 'androidTest'.
No dependencies

apk - Classpath packaged with the compiled 'main' classes.
No dependencies

archives - Configuration for archive artifacts.
No dependencies

compile - Classpath for compiling the main sources.
+--- com.android.support:appcompat-v7:22.2.1
|    \--- com.android.support:support-v4:22.2.1
|         \--- com.android.support:support-annotations:22.2.1
+--- com.android.support:design:22.2.1
|    +--- com.android.support:appcompat-v7:22.2.1 (*)
|    \--- com.android.support:support-v4:22.2.1 (*)
\--- com.shamanland:fonticon:0.1.8

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_debugAndroidTestApk - ## Internal use, do not manually configure ##

+--- com.android.support:support-annotations:22.2.1

+--- com.android.support.test:runner:0.3

| +--- com.android.support.test:exposed-instrumentation-api-publish:0.3

| +--- junit:junit:4.12

| | \--- org.hamcrest:hamcrest-core:1.3

| \--- com.android.support:support-annotations:22.2.0 -> 22.2.1

\--- com.android.support.test.espresso:espresso-core:2.2

+--- com.android.support.test.espresso:espresso-idling-resource:2.2

+--- com.squareup:javawriter:2.1.1

+--- javax.inject:javax.inject:1

+--- org.hamcrest:hamcrest-library:1.3

| \--- org.hamcrest:hamcrest-core:1.3

+--- com.android.support.test:rules:0.3

| \--- com.android.support.test:runner:0.3 (*)

+--- org.hamcrest:hamcrest-integration:1.3

| \--- org.hamcrest:hamcrest-library:1.3 (*)

+--- com.google.code.findbugs:jsr305:2.0.1

+--- javax.annotation:javax.annotation-api:1.2

\--- com.android.support.test:runner:0.3 (*)

_debugAndroidTestCompile - ## Internal use, do not manually configure ##

+--- com.android.support:support-annotations:22.2.1

+--- com.android.support.test:runner:0.3

| +--- com.android.support.test:exposed-instrumentation-api-publish:0.3

| +--- junit:junit:4.12

| | \--- org.hamcrest:hamcrest-core:1.3

| \--- com.android.support:support-annotations:22.2.0 -> 22.2.1

\--- com.android.support.test.espresso:espresso-core:2.2

+--- com.android.support.test.espresso:espresso-idling-resource:2.2

+--- com.squareup:javawriter:2.1.1

+--- javax.inject:javax.inject:1

+--- org.hamcrest:hamcrest-library:1.3

| \--- org.hamcrest:hamcrest-core:1.3

+--- com.android.support.test:rules:0.3

| \--- com.android.support.test:runner:0.3 (*)

+--- org.hamcrest:hamcrest-integration:1.3

| \--- org.hamcrest:hamcrest-library:1.3 (*)

+--- com.google.code.findbugs:jsr305:2.0.1

+--- javax.annotation:javax.annotation-api:1.2

\--- com.android.support.test:runner:0.3 (*)

_debugApk - ## Internal use, do not manually configure ##

+--- com.android.support:multidex:1.0.1

+--- com.android.support:appcompat-v7:22.2.1

| \--- com.android.support:support-v4:22.2.1

| \--- com.android.support:support-annotations:22.2.1

+--- com.android.support:design:22.2.1

| +--- com.android.support:appcompat-v7:22.2.1 (*)

| \--- com.android.support:support-v4:22.2.1 (*)

\--- com.shamanland:fonticon:0.1.8

_debugCompile - ## Internal use, do not manually configure ##

+--- com.android.support:multidex:1.0.1

+--- com.android.support:appcompat-v7:22.2.1

| \--- com.android.support:support-v4:22.2.1

| \--- com.android.support:support-annotations:22.2.1

+--- com.android.support:design:22.2.1

| +--- com.android.support:appcompat-v7:22.2.1 (*)

| \--- com.android.support:support-v4:22.2.1 (*)

\--- com.shamanland:fonticon:0.1.8

_debugUnitTestApk - ## Internal use, do not manually configure ##

No dependencies

_debugUnitTestCompile - ## Internal use, do not manually configure ##

No dependencies

_releaseApk - ## Internal use, do not manually configure ##

+--- com.android.support:multidex:1.0.1

+--- com.android.support:appcompat-v7:22.2.1

| \--- com.android.support:support-v4:22.2.1

| \--- com.android.support:support-annotations:22.2.1

+--- com.android.support:design:22.2.1

| +--- com.android.support:appcompat-v7:22.2.1 (*)

| \--- com.android.support:support-v4:22.2.1 (*)

\--- com.shamanland:fonticon:0.1.8

_releaseCompile - ## Internal use, do not manually configure ##

+--- com.android.support:multidex:1.0.1

+--- com.android.support:appcompat-v7:22.2.1

| \--- com.android.support:support-v4:22.2.1

| \--- com.android.support:support-annotations:22.2.1

+--- com.android.support:design:22.2.1

| +--- com.android.support:appcompat-v7:22.2.1 (*)

| \--- com.android.support:support-v4:22.2.1 (*)

\--- com.shamanland:fonticon:0.1.8

_releaseUnitTestApk - ## Internal use, do not manually configure ##

No dependencies

_releaseUnitTestCompile - ## Internal use, do not manually configure ##

No dependencies

androidJacocoAgent - The Jacoco agent to use to get coverage data.

\--- org.jacoco:org.jacoco.agent:0.7.4.201502262128

androidJacocoAnt - The Jacoco ant tasks to use to get execute Gradle tasks.

\--- org.jacoco:org.jacoco.ant:0.7.4.201502262128

+--- org.jacoco:org.jacoco.core:0.7.4.201502262128

| \--- org.ow2.asm:asm-debug-all:5.0.1

+--- org.jacoco:org.jacoco.report:0.7.4.201502262128

| +--- org.jacoco:org.jacoco.core:0.7.4.201502262128 (*)

| \--- org.ow2.asm:asm-debug-all:5.0.1

\--- org.jacoco:org.jacoco.agent:0.7.4.201502262128

androidTestApk - Classpath packaged with the compiled 'androidTest' classes.

No dependencies

androidTestCompile - Classpath for compiling the androidTest sources.

+--- com.android.support:support-annotations:22.2.1

+--- com.android.support.test:runner:0.3

| +--- com.android.support.test:exposed-instrumentation-api-publish:0.3

| +--- junit:junit:4.12

| | \--- org.hamcrest:hamcrest-core:1.3

| \--- com.android.support:support-annotations:22.2.0 -> 22.2.1

\--- com.android.support.test.espresso:espresso-core:2.2

+--- com.android.support.test.espresso:espresso-idling-resource:2.2

+--- com.squareup:javawriter:2.1.1

+--- javax.inject:javax.inject:1

+--- org.hamcrest:hamcrest-library:1.3

| \--- org.hamcrest:hamcrest-core:1.3

+--- com.android.support.test:rules:0.3

| \--- com.android.support.test:runner:0.3 (*)

+--- org.hamcrest:hamcrest-integration:1.3

| \--- org.hamcrest:hamcrest-library:1.3 (*)

+--- com.google.code.findbugs:jsr305:2.0.1

+--- javax.annotation:javax.annotation-api:1.2

\--- com.android.support.test:runner:0.3 (*)

androidTestProvided - Classpath for only compiling the androidTest sources.

No dependencies

androidTestWearApp - Link to a wear app to embed for object 'androidTest'.

No dependencies

apk - Classpath packaged with the compiled 'main' classes.

No dependencies

archives - Configuration for archive artifacts.

No dependencies

compile - Classpath for compiling the main sources.

+--- com.android.support:appcompat-v7:22.2.1

| \--- com.android.support:support-v4:22.2.1

| \--- com.android.support:support-annotations:22.2.1

+--- com.android.support:design:22.2.1

| +--- com.android.support:appcompat-v7:22.2.1 (*)

| \--- com.android.support:support-v4:22.2.1 (*)

\--- com.shamanland:fonticon:0.1.8

可以看出:com.android.support.test:runner:0.3 这个模块原本是依赖于com.android.support:support-annotations22.2.0版本，但由于你又在gradle.build中加了这行androidTestCompile 'com.android.support:support-annotations:22.2.1' 故gradle就会下载com.android.support:support-annotations22.2.1版本，而不会去下载com.android.support:support-annotations22.2.0版本，因此com.android.support.test:runner:0.3 就会被强转变依赖于com.android.support:support-annotations22.2.1版本
第二个问题，我还是利用上面gradle命令行打出的信息来看看：

debugApk - ## Internal use, do not manually configure ##
+--- com.android.support:multidex:1.0.1
+--- com.android.support:appcompat-v7:22.2.1
|    \--- com.android.support:support-v4:22.2.1
|         \--- com.android.support:support-annotations:22.2.1
+--- com.android.support:design:22.2.1
|    +--- com.android.support:appcompat-v7:22.2.1 (*)
|    \--- com.android.support:support-v4:22.2.1 (*)
\--- com.shamanland:fonticon:0.1.8

debugApk - ## Internal use, do not manually configure ##

+--- com.android.support:multidex:1.0.1

+--- com.android.support:appcompat-v7:22.2.1

| \--- com.android.support:support-v4:22.2.1

| \--- com.android.support:support-annotations:22.2.1

+--- com.android.support:design:22.2.1

| +--- com.android.support:appcompat-v7:22.2.1 (*)

| \--- com.android.support:support-v4:22.2.1 (*)

\--- com.shamanland:fonticon:0.1.8

仔细看上面的依赖，com.android.support:appcompat-v7:22.2.1 和com.android.support:design:22.2.1，有共同依赖一个com.android.support:support-v4:22.2.1库，且com.android.support:design:22.2.1 依赖于com.android.support:appcompat-v7:22.2.1，但从打印出的信息可以看出com.android.support:design:22.2.1 依赖两个库的信息被打了星号标记，这标记意思是忽略这两个依赖的意思，也就是说不去下载这两个库。
从上面的两个例子来看，gradle对于需要多个版本的依赖库来说，一般只会下载你配置导入那个版本，如果没有手动导入，那就会下载所有模块依赖的最新版本那个库，面对多个模块依赖同一个库，每个模块不都会去下载该依赖库，而是下载一个该依赖库，共享给多个模块。
修改配置文件为：

dependencies {
    compile 'com.android.support:appcompat-v7:22.2.1'
    compile ('com.android.support:design:22.2.1')
            {
                exclude group: 'com.android.support'
            }
    compile 'com.shamanland:fonticon:0.1.8'
    androidTestCompile 'com.android.support:support-annotations:22.2.1'
    androidTestCompile 'com.android.support.test:runner:0.3'
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2')
            {
                exclude  group:'com.android.support.test'
            }
}

dependencies {

compile 'com.android.support:appcompat-v7:22.2.1'

compile ('com.android.support:design:22.2.1')

{

exclude group: 'com.android.support'

}

compile 'com.shamanland:fonticon:0.1.8'

androidTestCompile 'com.android.support:support-annotations:22.2.1'

androidTestCompile 'com.android.support.test:runner:0.3'

androidTestCompile('com.android.support.test.espresso:espresso-core:2.2')

{

exclude group:'com.android.support.test'

}

打印信息：

$ gradlew -q app:dependencies

------------------------------------------------------------
Project :app
------------------------------------------------------------

_debugAndroidTestApk - ## Internal use, do not manually configure ##
+--- com.android.support:support-annotations:22.2.1
+--- com.android.support.test:runner:0.3
|    +--- com.android.support.test:exposed-instrumentation-api-publish:0.3
|    +--- junit:junit:4.12
|    |    \--- org.hamcrest:hamcrest-core:1.3
|    \--- com.android.support:support-annotations:22.2.0 -> 22.2.1
\--- com.android.support.test.espresso:espresso-core:2.2
     +--- com.android.support.test.espresso:espresso-idling-resource:2.2
     +--- com.squareup:javawriter:2.1.1
     +--- javax.inject:javax.inject:1
     +--- org.hamcrest:hamcrest-library:1.3
     |    \--- org.hamcrest:hamcrest-core:1.3
     +--- org.hamcrest:hamcrest-integration:1.3
     |    \--- org.hamcrest:hamcrest-library:1.3 (*)
     +--- com.google.code.findbugs:jsr305:2.0.1
     \--- javax.annotation:javax.annotation-api:1.2

_debugAndroidTestCompile - ## Internal use, do not manually configure ##
+--- com.android.support:support-annotations:22.2.1
+--- com.android.support.test:runner:0.3
|    +--- com.android.support.test:exposed-instrumentation-api-publish:0.3
|    +--- junit:junit:4.12
|    |    \--- org.hamcrest:hamcrest-core:1.3
|    \--- com.android.support:support-annotations:22.2.0 -> 22.2.1
\--- com.android.support.test.espresso:espresso-core:2.2
     +--- com.android.support.test.espresso:espresso-idling-resource:2.2
     +--- com.squareup:javawriter:2.1.1
     +--- javax.inject:javax.inject:1
     +--- org.hamcrest:hamcrest-library:1.3
     |    \--- org.hamcrest:hamcrest-core:1.3
     +--- org.hamcrest:hamcrest-integration:1.3
     |    \--- org.hamcrest:hamcrest-library:1.3 (*)
     +--- com.google.code.findbugs:jsr305:2.0.1
     \--- javax.annotation:javax.annotation-api:1.2

_debugApk - ## Internal use, do not manually configure ##
+--- com.android.support:multidex:1.0.1
+--- com.android.support:appcompat-v7:22.2.1
|    \--- com.android.support:support-v4:22.2.1
|         \--- com.android.support:support-annotations:22.2.1
+--- com.android.support:design:22.2.1
\--- com.shamanland:fonticon:0.1.8

_debugCompile - ## Internal use, do not manually configure ##
+--- com.android.support:multidex:1.0.1
+--- com.android.support:appcompat-v7:22.2.1
|    \--- com.android.support:support-v4:22.2.1
|         \--- com.android.support:support-annotations:22.2.1
+--- com.android.support:design:22.2.1
\--- com.shamanland:fonticon:0.1.8

_debugUnitTestApk - ## Internal use, do not manually configure ##
No dependencies

_debugUnitTestCompile - ## Internal use, do not manually configure ##
No dependencies

_releaseApk - ## Internal use, do not manually configure ##
+--- com.android.support:multidex:1.0.1
+--- com.android.support:appcompat-v7:22.2.1
|    \--- com.android.support:support-v4:22.2.1
|         \--- com.android.support:support-annotations:22.2.1
+--- com.android.support:design:22.2.1
\--- com.shamanland:fonticon:0.1.8

_releaseCompile - ## Internal use, do not manually configure ##
+--- com.android.support:multidex:1.0.1
+--- com.android.support:appcompat-v7:22.2.1
|    \--- com.android.support:support-v4:22.2.1
|         \--- com.android.support:support-annotations:22.2.1
+--- com.android.support:design:22.2.1
\--- com.shamanland:fonticon:0.1.8

_releaseUnitTestApk - ## Internal use, do not manually configure ##
No dependencies

_releaseUnitTestCompile - ## Internal use, do not manually configure ##
No dependencies

androidJacocoAgent - The Jacoco agent to use to get coverage data.
\--- org.jacoco:org.jacoco.agent:0.7.4.201502262128

androidJacocoAnt - The Jacoco ant tasks to use to get execute Gradle tasks.
\--- org.jacoco:org.jacoco.ant:0.7.4.201502262128
     +--- org.jacoco:org.jacoco.core:0.7.4.201502262128
     |    \--- org.ow2.asm:asm-debug-all:5.0.1
     +--- org.jacoco:org.jacoco.report:0.7.4.201502262128
     |    +--- org.jacoco:org.jacoco.core:0.7.4.201502262128 (*)
     |    \--- org.ow2.asm:asm-debug-all:5.0.1
     \--- org.jacoco:org.jacoco.agent:0.7.4.201502262128

androidTestApk - Classpath packaged with the compiled 'androidTest' classes.
No dependencies

androidTestCompile - Classpath for compiling the androidTest sources.
+--- com.android.support:support-annotations:22.2.1
+--- com.android.support.test:runner:0.3
|    +--- com.android.support.test:exposed-instrumentation-api-publish:0.3
|    +--- junit:junit:4.12
|    |    \--- org.hamcrest:hamcrest-core:1.3
|    \--- com.android.support:support-annotations:22.2.0 -> 22.2.1
\--- com.android.support.test.espresso:espresso-core:2.2
     +--- com.android.support.test.espresso:espresso-idling-resource:2.2
     +--- com.squareup:javawriter:2.1.1
     +--- javax.inject:javax.inject:1
     +--- org.hamcrest:hamcrest-library:1.3
     |    \--- org.hamcrest:hamcrest-core:1.3
     +--- org.hamcrest:hamcrest-integration:1.3
     |    \--- org.hamcrest:hamcrest-library:1.3 (*)
     +--- com.google.code.findbugs:jsr305:2.0.1
     \--- javax.annotation:javax.annotation-api:1.2

androidTestProvided - Classpath for only compiling the androidTest sources.
No dependencies

androidTestWearApp - Link to a wear app to embed for object 'androidTest'.
No dependencies

apk - Classpath packaged with the compiled 'main' classes.
No dependencies

archives - Configuration for archive artifacts.
No dependencies

compile - Classpath for compiling the main sources.
+--- com.android.support:appcompat-v7:22.2.1
|    \--- com.android.support:support-v4:22.2.1
|         \--- com.android.support:support-annotations:22.2.1
+--- com.android.support:design:22.2.1
\--- com.shamanland:fonticon:0.1.8

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$ gradlew -q app:dependencies

------------------------------------------------------------

Project :app

------------------------------------------------------------

_debugAndroidTestApk - ## Internal use, do not manually configure ##

+--- com.android.support:support-annotations:22.2.1

+--- com.android.support.test:runner:0.3

| +--- com.android.support.test:exposed-instrumentation-api-publish:0.3

| +--- junit:junit:4.12

| | \--- org.hamcrest:hamcrest-core:1.3

| \--- com.android.support:support-annotations:22.2.0 -> 22.2.1

\--- com.android.support.test.espresso:espresso-core:2.2

+--- com.android.support.test.espresso:espresso-idling-resource:2.2

+--- com.squareup:javawriter:2.1.1

+--- javax.inject:javax.inject:1

+--- org.hamcrest:hamcrest-library:1.3

| \--- org.hamcrest:hamcrest-core:1.3

+--- org.hamcrest:hamcrest-integration:1.3

| \--- org.hamcrest:hamcrest-library:1.3 (*)

+--- com.google.code.findbugs:jsr305:2.0.1

\--- javax.annotation:javax.annotation-api:1.2

_debugAndroidTestCompile - ## Internal use, do not manually configure ##

+--- com.android.support:support-annotations:22.2.1

+--- com.android.support.test:runner:0.3

| +--- com.android.support.test:exposed-instrumentation-api-publish:0.3

| +--- junit:junit:4.12

| | \--- org.hamcrest:hamcrest-core:1.3

| \--- com.android.support:support-annotations:22.2.0 -> 22.2.1

\--- com.android.support.test.espresso:espresso-core:2.2

+--- com.android.support.test.espresso:espresso-idling-resource:2.2

+--- com.squareup:javawriter:2.1.1

+--- javax.inject:javax.inject:1

+--- org.hamcrest:hamcrest-library:1.3

| \--- org.hamcrest:hamcrest-core:1.3

+--- org.hamcrest:hamcrest-integration:1.3

| \--- org.hamcrest:hamcrest-library:1.3 (*)

+--- com.google.code.findbugs:jsr305:2.0.1

\--- javax.annotation:javax.annotation-api:1.2

_debugApk - ## Internal use, do not manually configure ##

+--- com.android.support:multidex:1.0.1

+--- com.android.support:appcompat-v7:22.2.1

| \--- com.android.support:support-v4:22.2.1

| \--- com.android.support:support-annotations:22.2.1

+--- com.android.support:design:22.2.1

\--- com.shamanland:fonticon:0.1.8

_debugCompile - ## Internal use, do not manually configure ##

+--- com.android.support:multidex:1.0.1

+--- com.android.support:appcompat-v7:22.2.1

| \--- com.android.support:support-v4:22.2.1

| \--- com.android.support:support-annotations:22.2.1

+--- com.android.support:design:22.2.1

\--- com.shamanland:fonticon:0.1.8

_debugUnitTestApk - ## Internal use, do not manually configure ##

No dependencies

_debugUnitTestCompile - ## Internal use, do not manually configure ##

No dependencies

_releaseApk - ## Internal use, do not manually configure ##

+--- com.android.support:multidex:1.0.1

+--- com.android.support:appcompat-v7:22.2.1

| \--- com.android.support:support-v4:22.2.1

| \--- com.android.support:support-annotations:22.2.1

+--- com.android.support:design:22.2.1

\--- com.shamanland:fonticon:0.1.8

_releaseCompile - ## Internal use, do not manually configure ##

+--- com.android.support:multidex:1.0.1

+--- com.android.support:appcompat-v7:22.2.1

| \--- com.android.support:support-v4:22.2.1

| \--- com.android.support:support-annotations:22.2.1

+--- com.android.support:design:22.2.1

\--- com.shamanland:fonticon:0.1.8

_releaseUnitTestApk - ## Internal use, do not manually configure ##

No dependencies

_releaseUnitTestCompile - ## Internal use, do not manually configure ##

No dependencies

androidJacocoAgent - The Jacoco agent to use to get coverage data.

\--- org.jacoco:org.jacoco.agent:0.7.4.201502262128

androidJacocoAnt - The Jacoco ant tasks to use to get execute Gradle tasks.

\--- org.jacoco:org.jacoco.ant:0.7.4.201502262128

+--- org.jacoco:org.jacoco.core:0.7.4.201502262128

| \--- org.ow2.asm:asm-debug-all:5.0.1

+--- org.jacoco:org.jacoco.report:0.7.4.201502262128

| +--- org.jacoco:org.jacoco.core:0.7.4.201502262128 (*)

| \--- org.ow2.asm:asm-debug-all:5.0.1

\--- org.jacoco:org.jacoco.agent:0.7.4.201502262128

androidTestApk - Classpath packaged with the compiled 'androidTest' classes.

No dependencies

androidTestCompile - Classpath for compiling the androidTest sources.

+--- com.android.support:support-annotations:22.2.1

+--- com.android.support.test:runner:0.3

| +--- com.android.support.test:exposed-instrumentation-api-publish:0.3

| +--- junit:junit:4.12

| | \--- org.hamcrest:hamcrest-core:1.3

| \--- com.android.support:support-annotations:22.2.0 -> 22.2.1

\--- com.android.support.test.espresso:espresso-core:2.2

+--- com.android.support.test.espresso:espresso-idling-resource:2.2

+--- com.squareup:javawriter:2.1.1

+--- javax.inject:javax.inject:1

+--- org.hamcrest:hamcrest-library:1.3

| \--- org.hamcrest:hamcrest-core:1.3

+--- org.hamcrest:hamcrest-integration:1.3

| \--- org.hamcrest:hamcrest-library:1.3 (*)

+--- com.google.code.findbugs:jsr305:2.0.1

\--- javax.annotation:javax.annotation-api:1.2

androidTestProvided - Classpath for only compiling the androidTest sources.

No dependencies

androidTestWearApp - Link to a wear app to embed for object 'androidTest'.

No dependencies

apk - Classpath packaged with the compiled 'main' classes.

No dependencies

archives - Configuration for archive artifacts.

No dependencies

compile - Classpath for compiling the main sources.

+--- com.android.support:appcompat-v7:22.2.1

| \--- com.android.support:support-v4:22.2.1

| \--- com.android.support:support-annotations:22.2.1

+--- com.android.support:design:22.2.1

\--- com.shamanland:fonticon:0.1.8

比较上面两种配置compile信息部分，后面一种配置的 com.android.support:design:22.2.1 就没有输出两个打星号的依赖库信息了。
因此遇到这两种情况是，是gradle能自动帮我们解决掉了这两种情况，对于如何使用gralde命令行查看库依赖(depends)请看官方文档

参考链接

gradle 管理依赖库两个问题

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