使用注解@StringDef替代枚举-以切换环境为例

1. build.gradle添加依赖（Android Studio 3.0）：

compile 'com.android.support:support-annotations:25.3.1'
// 25.3.1 为编译的Android Support Library版本

2. 以一个切换环境的方法为例：

public class EnvironmentConfig {
public static String API_VERSION_NAME = "A";
public static String API_DOMAIN = "https://api-alpha.xxx.com";

public final static String ALPHA = "A";
public final static String UAT = "U";
public final static String PRODUCT= "";

@StringDef({ALPHA, UAT, PRODUCT})
@Retention(RetentionPolicy.SOURCE)
public @interface Environment {
}

public static void initEnvironment(@Environment String type) {
API_VERSION_NAME = type;
switch (type) {
case ALPHA: {
API_DOMAIN = "https://api-alpha.xxx.com";
}
case UAT: {
API_DOMAIN = "https://api-uat.xxx.com";
}
break;
default: {
API_DOMAIN = "https://api.xxx.com";
}
break;
}
}
}

3. 使用

public class MainApplication extends BaseApplication {
@Override
public void initData() {
super.initData();
EnvironmentConfig.initEnvironment(EnvironmentConfig.ALPHA);
}
}

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