相关疑难解决方法(0)

rt.jar的必要性是什么？

所以,我在系统上安装了多个版本的Java(1.7和1.6).我需要使用1.6,因此,在Ubuntu上,我做了一个更新替代--config java并将其更改为1.6.现在java -version告诉我我正在使用1.6.

所以,我正在尝试使用Maven构建.如果我做一个mvn干净安装,我最终得到以下错误:

[ERROR] bootstrap class path not set in conjunction with -source 1.6
/path/to/SomeResultSetStub.java:[32,7] error: SomeResultSetStub is not abstract and does not override abstract method <T>getObject(String,Class<T>) in ResultSet

我做了一些寻找那个错误,似乎我需要在某处设置某种BootClassPath,但我似乎无法找到这样做的非常明确的指令.

任何人都可以指导我解决错误吗？

我一直试图让它工作一段时间,但还没有运气.

我想JAVA_HOME指向JDK7但是我想为JVM 5编译一个项目.我已经阅读了文档,我在SO上发现了类似的帖子,但它们似乎都没有在我的设置中工作.

我首先尝试设置target,source但我收到了一个错误:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
        <source>1.5</source>
        <target>1.5</target>
    </configuration>
</plugin>

[ClassName]不是抽象的,不重写抽象方法getParentLogger()在CommonDataSource

据我所知,在JDK 7中更新了类,并且添加了抛出错误的额外方法.我需要使用具有旧实现的JDK 5的运行时,一切都应该正常工作.所以我这样做:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
        <verbose>true</verbose>
        <source>1.5</source>
        <target>1.5</target>
        <compilerArguments>
            <bootclasspath>${env.JAVA5_HOME}/jre/lib/rt.jar</bootclasspath>
        </compilerArguments>
    </configuration>
</plugin>

我在我的系统上正确设置了JAVA5_HOME,我可以看到它在日志中加载了正确的类,但是我遇到了另一个错误:

[loading ZipFileIndexFileObject[c:\Program Files\Java\jdk1.5.0_22\jre\lib\rt.jar(*.class)]]
...
...
[ClassName]错误:包javax.crypto不存在

这是公平的,因为我没有包括jce.jar(加密类)bootclasspath.但是有一件事让我感到困惑.即使bootclasspath只包含Java 5运行时,我在类路径中有很多来自JRE7的库.它们没有在任何地方指定.

[类文件的搜索路径:c:\ Program Files(x86)\ Java\jdk1.5.0_22\jre\lib\rt.jar,c:\ Program Files\Java\jdk1.7.0_02\jre\lib\ext\dnsns.jar,c:\ Program Files\Java\jdk1.7.0_02\jre\lib\ext\localedata.jar,c:\ Program Files\Java\jdk1.7.0_02\jre\lib\ext\sunec.jar, c:\ Program Files\Java\jdk1.7.0_02\jre\lib\ext\sunjce_provider.jar,c:\ Program Files\Java\jdk1.7.0_02\jre\lib\ext\sunmscapi.jar,c:\ Program Files\Java\jdk1.7.0_02\jre\lib\ext\zipfs.jar,...]

如果我尝试添加jce.jar(来自JRE5),我会回到第一个错误:

<plugin>
    <groupId>org.apache.maven.plugins</groupId> …

我正在将我的应用程序从java 1.6升级到1.7.当我尝试使用Maven 3.2.1进行构建时,我的构建失败并出现以下错误消息:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.0.2:compile (default-compile) on project my-app5: Compilation failure: Compilation failure:
[ERROR] could not parse error message: warning: [options] bootstrap class path not set in conjunction with -source 1.6  

我正在使用java 1.7热点,之前我使用的是1.6 jrockit.我的应用程序是多模块,很少有模块像往常一样编译和构建,这个模块失败了.

我已正确设置java home并且mvn --version显示在输出下方:

Apache Maven 3.2.1 (ea8b2b07643dbb1b84b6d16e1f08391b666bc1e9; 2014-02-14T23:07:52+05:30)
Maven home: C:\Users\me\Maven3\apache-maven-3.2.1-bin\apache-maven-3.2.1\bin\..
Java version: 1.7.0_51, vendor: Oracle Corporation
Java home: C:\Program Files\jdk17051\jre
Default locale: en_US, platform encoding: Cp1252
OS name: "windows 7", version: "6.1", arch: "amd64", family: "windows"  

我错过了什么吗？

我在gradle控制台中的构建时收到警告消息：

警告：[选项]引导类路径未与-source 1.7一起设置1警告

我怎样才能解决这个问题？

任何帮助表示赞赏！

我的Java 7项目在Gradle中正常运行,即使它依赖于它java.util.Optional.

我非常非常困惑.java.util.Optional在Java 8中只是一件事,对吧？

我有一个摇篮的项目,而且,我已经设置sourceCompatibility并targetCompatibility到1.7.

在这个模块的一个类中我导入java.util.Optional,我认为直到Java 8才包含它.

如果我运行gradlew clean assemble,编译器甚至会使用正确的选项进行调用.虽然有一个警告听起来有点可疑.然而,罐子建造得很好.

15:51:12.998 [DEBUG] [org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter] Executing actions for task ':core:compileJava'.
15:51:13.000 [DEBUG] [org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler] Compiler arguments: -source 1.7 -target 1.7 -d /Users/deejay/workspace/number-jumble/core/build/classes/main -g -encoding UTF-8 -classpath /Users/deejay/workspace/number-jumble/model/build/libs/model-1.0.jar:/Users/deejay/.gradle/caches/modules-2/files-2.1/com.badlogicgames.gdx/gdx/1.3.1/18995f8b7b19118975722370818023c76a86fdf4/gdx-1.3.1.jar:/Users/deejay/.gradle/caches/modules-2/files-2.1/com.badlogicgames.gdx/gdx-freetype/1.3.1/1f647429753c8c91fb8fc477ffe5a4c9cde2f429/gdx-freetype-1.3.1.jar:/Users/deejay/.gradle/caches/modules-2/files-2.1/com.google.guava/guava/18.0/cce0823396aa693798f8882e64213b1772032b09/guava-18.0.jar /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/NumberJumbleGame.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/complexity/ChangeComplexityScreen.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/libgdx/SizeToAndLayoutAction.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/libgdx/TimeLabel.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/services/AppropriatelySizedFontService.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/services/DateService.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/session/GameSessionUi.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/session/HardcodedStreakAssessmentService.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/session/LandscapeGameSessionUi.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/session/PortraitGameSessionUi.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/session/RackScreen.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/session/RackSummaryScreen.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/session/StreakAssessmentService.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/splash/ReturnSplashScreen.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/stats/GdxLocalStatisticsRepository.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/stats/MapBackedStatisticsRepository.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/stats/StatisticsRepository.java /Users/deejay/workspace/number-jumble/core/src/main/java/com/binarytweed/numberjumble/stats/StatisticsService.java
15:51:13.001 [INFO] [org.gradle.api.internal.tasks.compile.jdk6.Jdk6JavaCompiler] Compiling with JDK Java compiler API.
15:51:13.007 [ERROR] [system.err] …