在根目录中创建一个文件，例如：apikey.properties

SECRET_KEY=YOUR_SECRET_KEY

在您的build.gradle中阅读apikey.properties

def apikeyPropertiesFile = rootProject.file("apikey.properties")
def apikeyProperties = new Properties()
apikeyProperties.load(new FileInputStream(apikeyPropertiesFile))

android {
  defaultConfig { 
    buildConfigField("String", "SECRET_KEY", apikeyProperties['SECRET_KEY'])
  }
}

可以使用BuildConfig对象访问中的字段。

String secretKey = BuildConfig.SECRET_KEY;

1.在gradle.properties中写入代码

YOUR_ACCESS_PARAMS = "YOUR_VALUE"

1.将代码写入应用程序级别build.gradle

android{
    ...
     buildTypes.each{
        it.buildConfigField 'String', 'ACCESS_PARAMS', YOUR_ACCESS_PARAMS
    }
}

1.生成的BuildConfig.java如下：

public final class BuildConfig {  
    public static final boolean DEBUG = Boolean.parseBoolean("true");   
    public static final String APPLICATION_ID = "xxx.xxxxxxxx.xxx";   
    public static final String BUILD_TYPE = "debug";  
    public static final String FLAVOR = "";  
    public static final int VERSION_CODE = 1;  
    public static final String VERSION_NAME = "1.0.0";  
    // Fields from build type: debug  
    public static final String ACCESS_PARAMS = "YOUR_VALUE";  
}