不推荐使用CompileOptions.bootClasspath属性

Question

升级到Gradle 4.x后,我收到警告

不推荐使用CompileOptions.bootClasspath属性,并计划在Gradle 5.0中将其删除.请改用CompileOptions.bootstrapClasspath属性.

在我的一个项目中.bootClasspath我的build.gradle中没有看到任何调用或类似内容.这个警告意味着什么？

警告仅出现在公共子项目中,而不是核心中.

公共/的build.gradle:

apply plugin: 'com.android.library'

ext {
    PUBLISH_GROUP_ID = 'com.afollestad.material-dialogs'
    PUBLISH_ARTIFACT_ID = 'commons'
    PUBLISH_VERSION = '0.9.2.3'
    BUILD_TOOLS = "26.0.3"
    TARGET_SDK = 25
}

android {
    compileSdkVersion TARGET_SDK
    buildToolsVersion BUILD_TOOLS

    defaultConfig {
        minSdkVersion 16
        targetSdkVersion TARGET_SDK
        versionCode 1
        versionName PUBLISH_VERSION
    }
    lintOptions {
        checkReleaseBuilds false
    }
}

dependencies {
    implementation project(':core')
}

// Changes to this block must be applied in core/build.gradle and commons/build.gradle
task("javadoc", type: Javadoc) {
    description "Generates Javadoc API documentation for the main source code."
    source = android.sourceSets.main.java.srcDirs
    ext.androidJar = "${android.sdkDirectory}/platforms/${android.compileSdkVersion}/android.jar"
    classpath += files(ext.androidJar)
    exclude "**/BuildConfig.java"
    exclude "**/R.java"
    options.links("http://docs.oracle.com/javase/7/docs/api/");
    options.links("http://d.android.com/reference/");
}

核心/的build.gradle:

apply plugin: 'com.android.library'

ext {
    PUBLISH_GROUP_ID = 'com.afollestad.material-dialogs'
    PUBLISH_ARTIFACT_ID = 'core'
    PUBLISH_VERSION = '0.9.2.3'
    SUPPORT_LIBRARY_VERSION = '25.4.0'
    BUILD_TOOLS = "26.0.3"
    TARGET_SDK = 25
}

android {
    compileSdkVersion TARGET_SDK
    buildToolsVersion BUILD_TOOLS

    defaultConfig {
        minSdkVersion 16
        targetSdkVersion TARGET_SDK
        versionCode 1
        versionName PUBLISH_VERSION
        consumerProguardFiles 'progress-proguard.txt'
    }
    lintOptions {
        checkReleaseBuilds false
    }
}

dependencies {
    api "com.android.support:support-v13:$SUPPORT_LIBRARY_VERSION"
    api "com.android.support:appcompat-v7:$SUPPORT_LIBRARY_VERSION"
    api "com.android.support:recyclerview-v7:$SUPPORT_LIBRARY_VERSION"
    api "com.android.support:support-annotations:$SUPPORT_LIBRARY_VERSION"
    implementation "me.zhanghai.android.materialprogressbar:library:1.4.1"
}

// Changes to this block must be applied in core/build.gradle and commons/build.gradle
task("javadoc", type: Javadoc) {
    description "Generates Javadoc API documentation for the main source code."
    source = android.sourceSets.main.java.srcDirs
    ext.androidJar = "${android.sdkDirectory}/platforms/${android.compileSdkVersion}/android.jar"
    classpath += files(ext.androidJar)
    exclude "**/BuildConfig.java"
    exclude "**/R.java"
    options.links("http://docs.oracle.com/javase/7/docs/api/");
    options.links("http://d.android.com/reference/");
}

Answer 1

我认为这条关于java Classpath和旧JDK的消息,将其添加到您的gradle将解决它:

android {

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

建议使用java 9 JDK并卸载旧的JDK,然后将其包含在项目结构中:File- > Other settings- > Default project structure.

可能的结论:

android-studio的默认JDK是...\Android studio\jre(嵌入式JDK),如上图所示.此嵌入式JDK包含已弃用的bootClasspath.

使用包含bootstrapClasspath的新JDK 或修改你的compileOptions解决方案.

为什么旧的JDK(嵌入式)与新的gradle版本不兼容？

我不知道.

Answer 2

我的Gradle /usr/lib/jvm/java-8-openjdk-amd64/jre在Ubuntu上使用OpenJDK 8 (参见println System.getProperty("java.home")build.gradle中的添加.没有涉及Android Studio.

我可以通过显式设置sourceCompatibility和targetCompatibility1.7(默认值)来触发警告.通过将Java版本更改为

android {

    compileOptions {
        sourceCompatibility 1.8
        targetCompatibility 1.8
    }
}

警告消失了.

仅针对一个项目显示警告的原因是它不会重复.由于字母数字排序,commons之前配置.当我设置,并以1.8 ,警告进入.coresourceCompatibilitytargetCompatibilitycommonscore

所有项目的设置sourceCompatibility和targetCompatibility1.8都会完全删除警告.如果这是你想要的项目,以及为什么Gradle 4无法使用1.7的警告是两个单独的问题.