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

Question

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 
}

以下是运行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复杂性.我该如何解决此警告？

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!

---

UPDATE

我导航到Window> Preferences> Gradle我设置的"Java主页"的"工作区JRE" jdk1.6.0_35,

现在,当我运行Gradle jar任务时,我得到以下输出,

[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？

Answer 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"

要在项目中的所有编译任务上设置bootClasspath选项,可以使用TaskContainer上的withType()方法查找Compile类型的所有任务:

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

请参阅文档了解详细信

Answer 2

有关详细信息,请参阅交叉编译的javac文档,但基本上它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,您可能会使用,java.util.Deque但目标是jdk5.

我不相信gradle已经支持设置它.我发现你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,你似乎是在java6的jdk6上构建,所以我认为你可以安全地忽略警告.你确定gradle在jdk6下运行而不是7吗？