java - Gradle compileJava タスクの警告: [オプション] ブートストラップ クラス パスが -source 1.6 と組み合わせて設定されていません

Question

以下は、build.gradleファイルの内容です。

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 
}

以下は、Gradle jarタスクを実行した結果です。

[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] -----------------------------------------------------

ビルドが成功したと表示されていますが、この警告により、実行時の複雑さが少し心配になりました。この警告を解決するにはどうすればよいですか?

また、Eclipse Indigo を使用しています。また、プロジェクトの Java コンパイラとビルド パスを jdk1.6.0_35 に設定しています。

誰かもっと情報が必要なら、私に知らせてください！

---

アップデート

Window> Preferences>に移動しGradle、「Java ホーム」を「ワークスペース JRE」jdk1.6.0_35 に設定しました。

Gradle jarタスクを実行すると、次の出力が得られます。

[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] -----------------------------------------------------

どうする？

Answer 1

bootClasspath オプションを使用して、クラスパスをブートストラップできます。

apply plugin: 'java'

sourceCompatibility = 1.6
targetCompatibility = 1.6

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

プロジェクト内のすべてのコンパイル タスクで bootClasspath オプションを設定するには、TaskContainer で withType() メソッドを使用して、Compile タイプのすべてのタスクを検索します。

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

詳細については、ドキュメントを参照してください。

Answer 2

Rudik の回答は、Gradle 2.0 以降で動作するように少し変更する必要があります。「Compile」プロパティを「JavaCompile」に変更する必要があります。参照: Gradle 2.0 にアップグレードした後: ルート プロジェクトでプロパティ 'Compile' が見つかりませんでした

Google App Engine (Java 7) 用にコンパイルする Android Studio 2.2.2 (JDK8) で、元のポスターの問題に遭遇しました。このシナリオを修正するために、それに応じて変更された Rudik の回答を次に示します。

apply plugin: 'java'

sourceCompatibility = 1.7
targetCompatibility = 1.7

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

そして再び gradle.properties で、あなたのパスが何であれ、JDK へのパスを追加します (Mac 用など)

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

元の回答を投稿してくれた Rudik に感謝します。新しい回答を作成する代わりにコメントを追加したかったのですが、十分な評価ポイントがありませんでした (まだ)。