Gradle 中 buildConfigField的巧妙应用

当用AndroidStudio来进行Android项目开发时，build.gradle就是这个工具的核心部分，所有的依赖，debug/release设置，混淆等都在这里进行配置。
下面就主要来记录下利用buildConfigField来为我们的项目进行动态配置的目的
eg:debug:打印日志，在内网测试，利用签名
release:关闭日志，外网，签名等
先贴出一个完事的build.gradle文件，如下：

apply plugin: 'com.android.application'
apply plugin: 'AndResGuard'//利用微信的资源混淆工具
//apply plugin: 'io.fabric'

buildscript {
repositories {
jcenter()
maven { url 'https://maven.fabric.io/public' }
}
dependencies {
// The Fabric Gradle plugin uses an open ended version to react
// quickly to Android tooling updates
classpath 'io.fabric.tools:gradle:latest.integration'
}
}

repositories {
jcenter()
maven { url 'https://maven.fabric.io/public' }
}
android {
compileSdkVersion 21
buildToolsVersion "22.0.1"

packagingOptions {
exclude 'LICENSE.txt'
exclude 'META-INF/DEPENDENCIES'
exclude 'META-INF/dependencies'
exclude 'META-INF/DEPENDENCIES.txt'
exclude 'META-INF/dependencies.txt'
exclude 'META-INF/LGPL2.1'
exclude 'META-INF/LICENSE'
exclude 'META-INF/license'
exclude 'META-INF/LICENSE.txt'
exclude 'META-INF/license.txt'
exclude 'META-INF/NOTICE'
exclude 'META-INF/notice'
exclude 'META-INF/NOTICE.txt'
exclude 'META-INF/notice.txt'
exclude 'META-INF/README.txt'
exclude 'META-INF/services/javax.annotation.processing.Processor'
exclude '!META-INF/MANIFEST.MF'
exclude 'META-INF/MANIFEST.MF'

}

defaultConfig {
targetSdkVersion 21
// multiDexEnabled true
}

/**
* 这前用上面multiDexEnabled true时，
* 突然在5.0以下的手机上跑不起来，
* 改成下面这种写法就可以了。
*/
dexOptions {
jumboMode true
}

signingConfigs {
release {
try {
storeFile file("../keystore/Het_KeyStore.keystore")//这里替换成你自己项目生成的keystore的存储路径
storePassword "szhittech"
keyAlias "Clife"
keyPassword "szhittechclife"
} catch (ex) {
throw new InvalidUserDataException(ex.toString())
}
}

debug {
try {
storeFile file("../keystore/Het_KeyStore.keystore")
storePassword "szhittech"
keyAlias "Clife"
keyPassword "szhittechclife"
} catch (ex) {
throw new InvalidUserDataException(ex.toString())
}
}
}

buildTypes {
release {
buildConfigField("boolean", "LOG_DEBUG", "false")
buildConfigField "String", "SERVER_HOST", "\"api.clife.cn/\""
minifyEnabled true
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
//是否清理无用资源
shrinkResources true
//是否启用zipAlign压缩
zipAlignEnabled true
pseudoLocalesEnabled true
signingConfig signingConfigs.release
}

debug {
buildConfigField("boolean", "LOG_DEBUG", "true")
buildConfigField "String", "SERVER_HOST", "\"200.200.200.50/\""
minifyEnabled true//true：启用混淆,false:不启用
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
shrinkResources false
zipAlignEnabled true
pseudoLocalesEnabled true
signingConfig signingConfigs.release
}
}

sourceSets {
main {
manifest.srcFile 'AndroidManifest.xml'
assets.srcDirs = ['assets']
java.srcDirs = ['src']
res.srcDirs = ['res']
jniLibs.srcDirs = ['libs']
}
}

lintOptions {
abortOnError false

}

/* buildTypes{
debug{
signingConfig signingConfigs.HetConfig
}

release {
signingConfig signingConfigs.HetConfig
}
}*/
}
//微信资源混淆工具
andResGuard {
mappingFile = null
use7zip = true
keepRoot = false
// add <yourpackagename>.R.drawable.icon into whitelist.
// because the launcher will get the icon with his name
whiteList = [
"andresguard.tencent.com.andresguard_example.R.drawable.icon",
//https://docs.fabric.io/android/crashlytics/build-tools.html
"andresguard.tencent.com.andresguard_example.R.string.com.crashlytics.*"
]
compressFilePattern = [
"*.png",
"*.jpg",
"*.jpeg",
"*.gif",
"resources.arsc"
]
//修改成本地SDK中zipalign路径
// zipAlignPath = '/Users/sun/Library/Android/sdk/build-tools/21.1.1/zipalign'
zipAlignPath = ' D:\\eclipse\\all_adt-bundle-windows-x86_64-20140321\\adt-bundle-windows-x86_64-20140321\\sdk\\build-tools\\21.1.1\\zipalign'

//替换成本地7zip路径
//sevenZipPath = '/usr/local/bin/7za'
sevenZipPath = 'D:\\2345Soft\\7zip\\7-Zip\\7z'
}

dependencies {
compile fileTree(dir: 'compile-libs', include: '*.jar')
// provided files('../csleep/libs/butterknife-5.1.2.jar')
compile fileTree(dir: 'libs', include: '*.jar')
provided files('../CommonBusiness/build/intermediates/bundles/release/classes.jar')
// provided files('../CommonResource/build/intermediates/bundles/release/classes.jar')
compile project(':CLifeAsr')
compile project(':csleep')
compile project(':CommonResource')
provided files('../ShareSDK/libs/libammsdk.jar')
provided files('../ShareSDK/libs/open_sdk.jar')
provided files('../CommonBusiness/libs/eventbus.jar')
// configurations {
// all*.exclude group: 'com.android.support', module: 'support-v4'
// }

compile('com.crashlytics.sdk.android:crashlytics:2.5.2@aar') { transitive = true; }
}

这个build.gradle只是自己项目中用到的，肯定没有包含所有，也没有哪个项目会在build.gralde中把所有东西都用到。这里只想起个抛砖引玉的作用，这里没有的，google上肯定可以查到的。
下面就只说说build.gradle 中buildTypes中的buildConfigField的作用。
如上：

buildConfigField("boolean", "LOG_DEBUG", "true")
buildConfigField "String", "SERVER_HOST", "\"200.200.200.50/\""
1
2
看下groovy中的源码：

/**
* Adds a new field to the generated BuildConfig class.
*
* <p>The field is generated as: <code><type> <name> = <value>;</code>
*
* <p>This means each of these must have valid Java content. If the type is a String, then the
* value should include quotes.
*
* @param type the type of the field
* @param name the name of the field
* @param value the value of the field
*/
public void buildConfigField(
@NonNull String type,
@NonNull String name,
@NonNull String value) {
ClassField alreadyPresent = getBuildConfigFields().get(name);
if (alreadyPresent != null) {
logger.info(
"BuildType(${getName()}): buildConfigField '$name' value is being replaced: ${alreadyPresent.value} -> $value");
}
addBuildConfigField(AndroidBuilder.createClassField(type, name, value));
}

一目了然，这个方法接收三个非空的参数，第一个：确定值的类型，第二个：指定key的名字，第三个：传值
上面的意思是：为LOG_DEBUG = true
那这个值怎么读取呢？在Groovy中，直接由BuildConfig类点出key名来取值，如下：

if(BuildConfig.LOG_DEBUG){
//Debug，打印日志
Logger.init("AppPlusLog").setLogLevel(LogLevel.FULL);
}else{
//release,关闭日志
Logger.init("AppPlusLog").setLogLevel(LogLevel.None);
}

同样的，网络切换也可以这样设置

buildConfigField "String", "SERVER_HOST", "\"200.200.200.50/\""

//取值
String host = BuildConfig.SERVER_HOST;
//然后再把这个host替换掉默认的那个
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