我正在尝试使用Notepad ++作为我的一体化工具编辑,运行,编译等.
我安装了JRE,并且已将路径变量设置为.../bin目录.
当我在Notepad ++中运行"Hello world"时,我收到以下消息:
java.lang.UnsupportedClassVersionError: test_hello_world :
Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(Unknown Source)
.........................................
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我认为这里的问题是版本问题; 某些版本的Java可能是旧的或太新的.
.../binJRE或JDK中的变量有什么区别?图片:
命令提示符显示版本
图片错误
import java.applet.Applet;
import java.awt.*;
public class Hello extends Applet {
// Java applet to draw "Hello World"
public void paint (Graphics page) {
page.drawString ("Hello World!", 50, 50);
}
}
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<HTML>
<HEAD>
<TITLE>HelloWorld Applet</TITLE>
</HEAD>
<BODY>
<APPLET CODE="Hello.class" WIDTH=300 HEIGHT=150>
</APPLET>
</BODY>
</HTML>
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Hello : Unsupported major.minor version 52.0
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问题可能是什么?
可能重复:
不支持的主要.minor版本51.0
我正在尝试构建一个应用程序,但它给出了一些错误.我的JDK版本如下:
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)
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这是我的错误日志:
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 …Run Code Online (Sandbox Code Playgroud) 我按照以下步骤安装了maven :(教程)
JAVA_HOME=/Library/Java/Home
export M2_HOME=/Users/steven/zimmermann/maven
export M2=$M2_HOME/bin
export PATH=$M2:$PATH
echo $JAVA_HOME
echo $M2_HOME
echo $M2
echo $PATH
nano .bash_profile
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然后我在.bash_profile中写了回声,就像这样:
JAVA_HOME=/usr/libexec/java_home
M2_HOME=/path/to/your/apache-maven-3.x.x
M2=/path/to/your/apache-maven-3.x.x/bin
PATH=/path/to/maven/bin:/$….bla-bla-bla…
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我也在.bashrc中写了这个
export M2_HOME=/Users/steven/zimmermann/maven
export M2=$M2_HOME/bin
export PATH=$M2:$PATH
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现在,当我想检查版本(mvn -v)时,我得到以下异常:我认为有一些版本错误,但我不知道.
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/maven/cli/MavenCli : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:637)
at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:401)
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:254)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
at org.codehaus.plexus.classworlds.launcher.Launcher.getMainClass(Launcher.java:144)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:266) …Run Code Online (Sandbox Code Playgroud) 可能重复:
不支持的主要.minor版本51.0
我安装了JDK7,一个简单的hello word程序得到编译,但是当我运行它时,我得到了以下异常.
Exception in thread "main" java.lang.UnsupportedClassVersionError: a (Unsupported major.minor version 51.0)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
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我检查java -version了命令提示符,它显示了Java版本1.4.2_03但是当我尝试从java.com安装新的java版本时它说我推荐了Java 7版本.
我最近卸载了Java 8,使用Java 6,因为我希望我的代码/创建可以被更多人使用,而不仅仅是Java 8上的.当我这样做mvn - version时返回:
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/maven/cli/MavenCli : 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 java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:401)
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:254)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
at org.codehaus.plexus.classworlds.launcher.Launcher.getMainClass(Launcher.java:144)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:266)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
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当我这样做时java -version:
java version "1.6.0_45"
Java(TM) SE Runtime Environment (build 1.6.0_45-b06)
Java HotSpot(TM) 64-Bit Server VM (build 20.45-b01, mixed …Run Code Online (Sandbox Code Playgroud) 当我运行java程序时收到此错误..你能否建议我们为什么会收到此错误:
Exception in thread "main" java.lang.UnsupportedClassVersionError:
GenerateInvoice (Unsupported major.minor version 49.0)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:539)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)
at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
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[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.749s
[INFO] Finished at: Fri Jun 21 02:14:32 IST 2013
[INFO] Final Memory: 4M/15M
[INFO] ------------------------------------------------------------------------
**[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project spring-social-twitter4j: Execution default-compile of goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile failed: A required class was missing while executing org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile: org/codehaus/plexus/compiler/CompilerException**
[ERROR] -----------------------------------------------------
[ERROR] realm = plugin>org.apache.maven.plugins:maven-compiler-plugin:2.3.2
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
[ERROR] urls[0] = file:/C:/Users/SS%20Computer/.m2/repository/org/apache/maven/plugins/maven-compiler-plugin/2.3.2/maven-compiler-plugin-2.3.2.jar
[ERROR] urls[1] = file:/C:/Users/SS%20Computer/.m2/repository/org/codehaus/plexus/plexus-utils/1.1/plexus-utils-1.1.jar
[ERROR] Number of foreign imports: 1 …Run Code Online (Sandbox Code Playgroud) org.apache.catalina.core.ContainerBase addChildInternal
SEVERE: ContainerBase.addChild: start:
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/CollegeWebsite]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:895)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:871)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:615)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:962)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1603)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:469)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:332)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:597)
at java.lang.Thread.run(Thread.java:637)
Caused by: java.lang.UnsupportedClassVersionError: com/Servlets/AddCourse : Unsupported major.minor version 51.0 (unable to load class com.Servlets.AddCourse)
at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2893)
at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1170)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1678)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1556)
at org.apache.catalina.startup.WebAnnotationSet.loadClass(WebAnnotationSet.java:480)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:130)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:66)
at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:381)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:858)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:345)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5161)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
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