Gradle compileJava 任务警告：[options] 引导类路径未与 -source 1.6 一起设置

Posted 2023-02-26

【中文标题】Gradle compileJava 任务警告：[options] 引导类路径未与 -source 1.6 一起设置

【英文标题】：Gradle compileJava task warning: [options] bootstrap class path not set in conjunction with -source 1.6

【发布时间】：2013-05-16 18:52:12

【问题描述】：

以下是build.gradle文件的内容：

apply plugin: 'java'

archivesBaseName    = 'foo-bar'
version             = '1.0'
sourceCompatibility = JavaVersion.VERSION_1_6
targetCompatibility = JavaVersion.VERSION_1_6

sourceSets.main.resources.exclude 'foo.jks'

compileJava
    println project.sourceCompatibility 
    println project.targetCompatibility 
    println sourceCompatibility 
    println targetCompatibility 

下面是运行 Gradle jar 任务的结果：

[sts] -----------------------------------------------------
[sts] Starting Gradle build for the following tasks: 
[sts]      :jar
[sts] -----------------------------------------------------
1.6
1.6
1.6
1.6
:compileJavawarning: [options] bootstrap class path not set in conjunction with -source 1.6
1 warning

:processResources UP-TO-DATE
:classes
:jar

BUILD SUCCESSFUL

Total time: 1 mins 3.072 secs
[sts] -----------------------------------------------------
[sts] Build finished succesfully!
[sts] Time taken: 1 min, 3 sec
[sts] -----------------------------------------------------

虽然它声称构建成功，但警告让我有点担心运行时并发症。如何解决此警告？

另外，我正在使用 Eclipse Indigo。我将项目的 Java 编译器和构建路径设置为 jdk1.6.0_35。

如果有人需要更多信息，请告诉我！

---

更新

我导航到 Window > Preferences > Gradle 并将“Java Home”设置为“Workspace JRE”jdk1.6.0_35，

现在我在运行 Gradle jar 任务时得到以下输出，

[sts] -----------------------------------------------------
[sts] Starting Gradle build for the following tasks: 
[sts]      :jar
[sts] -----------------------------------------------------
1.6
1.6
1.6
1.6
:compileJavawarning: java\lang\Enum.class(java\lang:Enum.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: java\lang\Comparable.class(java\lang:Comparable.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: java\lang\Object.class(java\lang:Object.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: java\io\Serializable.class(java\io:Serializable.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: java\lang\String.class(java\lang:String.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: java\io\InputStream.class(java\io:InputStream.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: java\security\KeyStore.class(java\security:KeyStore.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: javax\crypto\Cipher.class(javax\crypto:Cipher.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: javax\crypto\spec\SecretKeySpec.class(javax\crypto\spec:SecretKeySpec.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: javax\xml\bind\DatatypeConverter.class(javax\xml\bind:DatatypeConverter.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: java\lang\CloneNotSupportedException.class(java\lang:CloneNotSupportedException.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: java\lang\Class.class(java\lang:Class.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: java\lang\ClassLoader.class(java\lang:ClassLoader.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: java\security\KeyStore$LoadStoreParameter.class(java\security:KeyStore$LoadStoreParameter.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: java\io\Closeable.class(java\io:Closeable.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: java\lang\AutoCloseable.class(java\lang:AutoCloseable.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: java\lang\Exception.class(java\lang:Exception.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: java\lang\Throwable.class(java\lang:Throwable.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: java\security\cert\Certificate.class(java\security\cert:Certificate.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: java\security\Key.class(java\security:Key.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: java\security\spec\KeySpec.class(java\security\spec:KeySpec.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: javax\crypto\SecretKey.class(javax\crypto:SecretKey.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: java\lang\Error.class(java\lang:Error.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: java\security\KeyStoreException.class(java\security:KeyStoreException.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: java\security\GeneralSecurityException.class(java\security:GeneralSecurityException.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: java\lang\RuntimeException.class(java\lang:RuntimeException.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: java\io\IOException.class(java\io:IOException.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: java\security\NoSuchAlgorithmException.class(java\security:NoSuchAlgorithmException.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: java\security\cert\CertificateException.class(java\security\cert:CertificateException.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: javax\crypto\NoSuchPaddingException.class(javax\crypto:NoSuchPaddingException.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: java\security\InvalidKeyException.class(java\security:InvalidKeyException.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: java\security\KeyException.class(java\security:KeyException.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: java\nio\ByteBuffer.class(java\nio:ByteBuffer.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: javax\crypto\IllegalBlockSizeException.class(javax\crypto:IllegalBlockSizeException.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: javax\crypto\BadPaddingException.class(javax\crypto:BadPaddingException.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: java\lang\StringBuilder.class(java\lang:StringBuilder.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: java\lang\AbstractStringBuilder.class(java\lang:AbstractStringBuilder.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: java\lang\CharSequence.class(java\lang:CharSequence.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: java\lang\StringBuffer.class(java\lang:StringBuffer.class): major version 51 is newer than 50, the highest major version supported by this compiler.
It is recommended that the compiler be upgraded.
39 warnings

:processResources UP-TO-DATE
:classes
:jar

BUILD SUCCESSFUL

Total time: 1.96 secs
[sts] -----------------------------------------------------
[sts] Build finished succesfully!
[sts] Time taken: 0 min, 1 sec
[sts] -----------------------------------------------------

做什么？

【问题讨论】：

检查你的 JAVA_HOME 环境变量

【参考方案1】：

您可以使用 bootClasspath 选项引导类路径：

apply plugin: 'java'

sourceCompatibility = 1.6
targetCompatibility = 1.6

compileJava.options.bootClasspath = "$JDK6_HOME/jre/lib/rt.jar"

要为项目中的所有编译任务设置 bootClasspath 选项，您可以使用 TaskContainer 上的 withType() 方法来查找所有编译类型的任务：

apply plugin: 'java'

sourceCompatibility = 1.6
targetCompatibility = 1.6

tasks.withType(JavaCompile) 
    options.bootstrapClasspath = files("$JDK6_HOME/jre/lib/rt.jar")

gradle.properties：

JDK6_HOME=C:/JAVA/jdk6

详情请见documentation。

【讨论】：

CompileOptions.bootClasspath 的文档说Only takes effect if fork is true。关于fork：Defaults to false。所以我担心你的例子遗漏了一些东西。

在构建脚本中硬编码 JDK 路径看起来是一种非常糟糕的做法。

我同意你的看法。但这只是样本。

@PaoloFulgoni：我认为 Rudik 的意思是在 $GRADLE_USER_HOME/gradle.properties 中定义 JDK6_HOME，因此它可以基于每个用户进行配置，而不是签入 VCS。

如果你想在用户没有声明 JDK6_HOME 的情况下避免构建错误，你可以添加这个 if 语句：if (project.hasProperty('JDK6_HOME')) options.bootClasspath = "$JDK6_HOME/jre/lib/rt.jar"

【参考方案2】：

Rudik 的回答需要稍作修改才能与 Gradle 2.0 及更高版本一起使用：“Compile”属性必须更改为“JavaCompile”。见：After upgrading to Gradle 2.0: Could not find property 'Compile' on root project

我在为 Google App Engine (Java 7) 编译 android Studio 2.2.2 (JDK8) 时遇到了原始发帖人的问题。以下是 Rudik 的答案，经过相应修改以解决这种情况：

apply plugin: 'java'

sourceCompatibility = 1.7
targetCompatibility = 1.7

tasks.withType(JavaCompile) 
    options.bootClasspath = "$JDK7_HOME/jre/lib/rt.jar"

再次在 gradle.properties 中，将您的路径添加到 JDK，例如适用于 Mac

JDK7_HOME=/Library/Java/JavaVirtualMachines/jdk1.7.0_67.jdk/Contents/Home

再次感谢 Rudik 发布原始答案。我想添加评论而不是创建新答案，但没有足够的声望点（还）。

【参考方案3】：

在工作空间级别为 gradle 定义 JVM 的解决方案并不理想。如果在不同的 JVM 上有多个项目/构建，则无法使用。

在带有 Spring Gradle 插件 (3.3.0) 的 Eclipse Kepler 中，可以为您的 gradle 构建任务（外部工具）定义 JVM。

在外部工具配置 | 参数 | Java Home您可以定义应该使用哪个 JVM 进行构建。

【参考方案4】：

请参阅cross compilation for details 上的 javac 文档，但基本上这意味着您可以针对目标版本上不存在或不同的 jdk 类进行编译。例如，也许您使用java.util.Deque，但目标是 jdk5。

我不相信 gradle 已内置支持设置此项。我发现您需要手动调整编译任务。例如

def bootClasspathStr = "$yourJavaVersionXInstallationPath/jre/lib/rt.jar"
project.tasks.withType(AbstractCompile,  AbstractCompile ac ->
    ac.options.bootClasspath = bootClasspathStr // options is always there but not defined on AbstractCompile so going to hit it anyway
)

说了这么多，您似乎是在 jdk6 上为 java6 构建的，所以我认为您可以放心地忽略该警告。你确定 gradle 是在 jdk6 而不是 7 下运行的吗？

【讨论】：

首先，感谢您的反馈。其次，我想我现在在 jdk6 下运行 gradle，但我不确定。想看看我的更新吗？

您的更新明确表明您正在使用带有 v7 rt.jar 的 v6 编译器。基本上，您设法使用正确的编译器进行 gradle 编译，但仍然使用错误的引导类路径。我不做日食，所以恐怕我无能为力了。

在调试模式下运行你的构建（pass -d）会告诉你你正在使用什么jvm。您还应该通过从 cli 运行构建来确认这是否是特定于 Eclipse 的问题。

@Ryan Stewart，原来我在 eclipse.ini 文件中指定了 Java 7 JVM。 -_-