java.lang.UnsupportedClassVersionError Unsupported major.minor version 51.0
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unsupported major .minor version 51.0
我正试图构建一个应用程序，但它给出了一些错误。我的JDK版本如下：
1 2 3 | java version"1.6.0_30" Java(TM) SE Runtime Environment (build 1.6.0_30-b12) Java HotSpot(TM) Client VM (build 20.5-b03, mixed mode, sharing) |
这是我的错误日志：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 | Buildfile: build.xml compile: [echo] Compiling the service.... [echo] ...mkdir for classes first.... [echo] ...java classes next.... [echo] ...mkdir for generated code next.... [echo] ...generate stubs/skeletons next.... [wscompile] command line: wscompile -d /home/vivekray/program/MTrans/WEB-INF/classes -features:wsi,documentliteral -gen:server -keep -model /home/vivekray/program/MTrans/WEB-INF/model.gz -verbose -Xprintstacktrace /home/vivekray/program/MTrans/src/config.xml -classpath /home/vivekray/program/MTrans/WEB-INF:/home/vivekray/program/MTrans/WEB-INF/classes:/home/vivekray/program/MTrans/lib/log4j-1.2.16.jar:/home/vivekray/jwsdp-2.0/jwsdp-shared/lib/mail.jar:/home/vivekray/jwsdp-2.0/jwsdp-shared/lib/activation.jar:/home/vivekray/jwsdp-2.0/jaxp/lib/jaxp-api.jar:/home/vivekray/jwsdp-2.0/jaxp/lib/endorsed/dom.jar:/home/vivekray/jwsdp-2.0/jaxp/lib/endorsed/sax.jar:/home/vivekray/jwsdp-2.0/jaxp/lib/endorsed/xalan.jar:/home/vivekray/jwsdp-2.0/jaxp/lib/endorsed/xercesImpl.jar:/home/vivekray/jwsdp-2.0/jaxrpc/lib/jaxrpc-api.jar:/home/vivekray/jwsdp-2.0/jaxrpc/lib/jaxrpc-spi.jar:/home/vivekray/jwsdp-2.0/jaxrpc/lib/jaxrpc-impl.jar:/home/vivekray/jwsdp-2.0/saaj/lib/saaj-api.jar:/home/vivekray/jwsdp-2.0/saaj/lib/saaj-impl.jar:/home/vivekray/jwsdp-2.0/jwsdp-shared/lib/relaxngDatatype.jar:/home/vivekray/jwsdp-2.0/jwsdp-shared/lib/xsdlib.jar:/home/vivekray/jwsdp-2.0/jwsdp-shared/lib/jax-qname.jar:/home/vivekray/jwsdp-2.0/apache-ant/lib/ant.jar:/home/vivekray/jwsdp-2.0/fastinfoset/lib/FastInfoset.jar:/home/vivekray/Softwares/apache-tomcat-7.0.27/lib/servlet-api.jar [wscompile] [creating model: mtransservice] [wscompile] [creating service: Mtransservice] BUILD FAILED java.lang.UnsupportedClassVersionError: in/cdac/mobile/computing/mtrans/MtransService : Unsupported major.minor version 51.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) at java.lang.ClassLoader.defineClass(ClassLoader.java:615) at org.apache.tools.ant.AntClassLoader.defineClassFromData(AntClassLoader.java:1146) at org.apache.tools.ant.AntClassLoader.getClassFromStream(AntClassLoader.java:1324) at org.apache.tools.ant.AntClassLoader.findClassInComponents(AntClassLoader.java:1388) at org.apache.tools.ant.AntClassLoader.findClass(AntClassLoader.java:1341) at org.apache.tools.ant.AntClassLoader.loadClass(AntClassLoader.java:1088) at java.lang.ClassLoader.loadClass(ClassLoader.java:295) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at com.sun.xml.rpc.processor.modeler.rmi.RmiUtils.getLoadableClassName(RmiUtils.java:78) at com.sun.xml.rpc.processor.modeler.rmi.RmiUtils.getRealName(RmiUtils.java:54) at com.sun.xml.rpc.processor.modeler.rmi.RmiModeler.modelPort(RmiModeler.java:676) at com.sun.xml.rpc.processor.modeler.rmi.RmiModeler.buildLiteralModel(RmiModeler.java:603) at com.sun.xml.rpc.processor.modeler.rmi.RmiModeler.buildModel(RmiModeler.java:457) at com.sun.xml.rpc.processor.config.ModelInfo.buildModel(ModelInfo.java:88) at com.sun.xml.rpc.processor.Processor.runModeler(Processor.java:63) at com.sun.xml.rpc.tools.wscompile.CompileTool.run(CompileTool.java:714) at com.sun.xml.rpc.util.ToolBase.run(ToolBase.java:43) at com.sun.xml.rpc.tools.ant.Wscompile.execute(Wscompile.java:746) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288) at sun.reflect.GeneratedMethodAccessor3.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.Target.execute(Target.java:357) at org.apache.tools.ant.Target.performTasks(Target.java:385) at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1337) at org.apache.tools.ant.Project.executeTarget(Project.java:1306) at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41) at org.apache.tools.ant.Project.executeTargets(Project.java:1189) at org.apache.tools.ant.Main.runBuild(Main.java:758) at org.apache.tools.ant.Main.startAnt(Main.java:217) at org.apache.tools.ant.launch.Launcher.run(Launcher.java:257) at org.apache.tools.ant.launch.Launcher.main(Launcher.java:104) Total time: 1 second |
这些人给了你失败的原因，但没有告诉你如何解决。即使您有一个JDK与您正在尝试的JVM相匹配，这个问题也可能出现。
Projt>属性-> Java编译器
启用项目特定的设置。
然后选择编译器兼容级别为1.6或1.5，构建并测试应用程序。
现在应该没事了。
以下是版本列表：
1 2 3 4 5 6 7 8 9 | Java SE 9 = 53, Java SE 8 = 52, Java SE 7 = 51, Java SE 6.0 = 50, Java SE 5.0 = 49, JDK 1.4 = 48, JDK 1.3 = 47, JDK 1.2 = 46, JDK 1.1 = 45 |
版本51是Java 7，您可能使用了错误的JDK。检查java_主页。
如前所述，在二进制兼容性下
我遇到了同样的问题，当jdk 1.7被用于编译时，jre1.4被用于执行。
我的解决方案是通过在现有路径设置之前添加路径名c:glassfish3jdk7in来设置环境变量路径。更新后的值为"c:glassfish3jdk7in；c:sunsdkin"。更新之后，问题就消失了。
这意味着您在一个特定的JDK下编译类，然后尝试在旧版本的JDK下运行它们。
使用Maven并使用Maven编译器插件显式调用实际的正确版本JDK JavaC.EXE命令，因为Maven可以运行任何版本；这也捕捉了Javac中的愚蠢的长期错误，它在编译早期Java JAVE时没有发现运行时中断类版本JAR和丢失类/方法/属性。艾斯！后面的部分可以通过在新的类、方法和属性中添加版本属性，或者单独的编译器版本控制数据来很容易地在Java 1.5 +中被固定，所以Sun和Oracle是一个非常愚蠢的疏忽。
确保在编译/运行时使用了正确的SDK，并且确保使用了source/target 1.7。