Android Studio:包含Google地图时的编译器设置

Question

我在Android Studio中创建了一个新项目,并添加了Google地图活动.

我收到这些警告:

warning: com/google/android/gms/maps/GoogleMap.class(com/google/android/gms/maps:GoogleMap.class): major version 51 is newer than 50, the highest major version supported by this compiler.
It is recommended that the compiler be upgraded.
warning: com/google/android/gms/maps/SupportMapFragment.class(com/google/android/gms/maps:SupportMapFragment.class): major version 51 is newer than 50, the highest major version supported by this compiler.
It is recommended that the compiler be upgraded.
warning: com/google/android/gms/maps/model/LatLng.class(com/google/android/gms/maps/model:LatLng.class): major version 51 is newer than 50, the highest major version supported by this compiler.
It is recommended that the compiler be upgraded.
warning: com/google/android/gms/maps/model/MarkerOptions.class(com/google/android/gms/maps/model:MarkerOptions.class): major version 51 is newer than 50, the highest major version supported by this compiler.
It is recommended that the compiler be upgraded.
warning: com/google/android/gms/maps/model/Marker.class(com/google/android/gms/maps/model:Marker.class): major version 51 is newer than 50, the highest major version supported by this compiler.
It is recommended that the compiler be upgraded.

我的猜测是我有一个JDK未命中赛或其他什么.我安装了JDK 7,当我进行javac -version时,我看到1.7.0_65.我在Android Studio的首选项中更改了Project字节码版本,但没有更改这些警告.

我的build.gradle有这个

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    // You must install or update the Google Repository through the SDK manager to use this dependency.
    compile 'com.google.android.gms:play-services:5.0.77'
    compile 'com.android.support:support-v13:18.0.+'
}

我需要做些什么来修复这些警告,还是应该在Android Studio中忽略它们？

Answer 1

"主要版本"表示Java版本.Java 7 = 51,Java 6 = 50.代码是为Java 7编写的,这是Android的dex支持的.我不确定你所构建的是没有为Java 7设置的,但这就是问题所在.项目中的Maven构建工作正常.我没有看到你提到的错误,也可能与Java 6 vs 7有关.

Answer 2

我能够根据Jason Hocker的提示和答案来解决这个问题.将此添加到您的androidgradle任务:

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_7
    targetCompatibility JavaVersion.VERSION_1_7
}

请注意,您必须安装Java 7 JDK.我还必须将此添加到我gradlew的允许gradle找到正确的JDK:

export JAVA_HOME=$(/usr/libexec/java_home -v 1.7)