java - Android Studio - 将字节码转换为 dex 时出错，原因 : Dex cannot parse version 52 byte code

Question

下面是我的 build.gradle 的一个 android studio 项目的内容:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "25.0.0"
    defaultConfig {
        applicationId "com.example.nariman.myapplication"
        minSdkVersion 15
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_7
        targetCompatibility JavaVersion.VERSION_1_7
    }
}
dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:24.2.1'
    compile 'com.android.support:design:24.2.1'
    compile 'net.time4j:time4j-calendar:4.20'
    compile 'net.time4j:time4j-olson:4.0'
    testCompile 'junit:junit:4.12'
}

但我得到以下错误:

Error:Error converting bytecode to dex:
Cause: Dex cannot parse version 52 byte code.
This is caused by library dependencies that have been compiled using Java 8 or above.
If you are using the 'java' gradle plugin in a library submodule add 
targetCompatibility = '1.7'
sourceCompatibility = '1.7'
to that submodule's build.gradle file.

如您所见，我已经尝试添加 targetCompatibility 和 sourceCompatibility，但问题仍然存在。

我搜索了一下，似乎有类似的问题报告，但现在似乎还没有找到解决方案。

Answer 1

我需要使用最新版本的 time4j ，因此无法回到 Java 7 版本的 time4j 库。我发现有一个针对 time4j 的姐妹项目，它是针对 Andriod 的，它被称为 time4a 或 time4j-android 。所以我改变了 build.gradle 如下，它解决了这个问题:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "25.0.0"
    defaultConfig {
        applicationId "com.example.nariman.myapplication"
        minSdkVersion 15
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

}
dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:24.2.1'
    compile 'com.android.support:design:24.2.1'
    compile group: 'net.time4j', name: 'time4j-android', version: '3.24-2016i'
    testCompile 'junit:junit:4.12'
}

这一行解决了我的问题:

compile group: 'net.time4j', name: 'time4j-android', version: '3.24-2016i'