修复java.lang.UnsupportedClassVersionError的问题:不支持的major.minor版本52 [英] Problems fixing java.lang.UnsupportedClassVersionError: Unsupported major.minor version 52

问题描述

我已经阅读了所有可以找到的关于此的文章，但是我似乎无法克服这个错误来使我的Maven Spring MVC Web应用程序正常工作.当我访问本地主机或控制器中指定的任何URI时，我只会获得HTTP状态500.

I've read all of the posts about this that I could find, but I can't seem to get past this error to get my maven spring mvc web application working. I just get an HTTP status 500 when i visit localhost or any of the URIs specified in my controllers.

据我了解，出现此问题的原因是，编译时使用的JDK比运行时使用的JDK高.但是在我看来，对我而言，对JDK或JRE的所有引用都是相同的.(1.8)根据此堆栈溢出文章，看来我需要使用Java 1.8，所以我不确定问题出在哪里:

From my understanding, the problem occurs because of a higher JDK used at compile time than used at runtime. But it seems to me like all of the references to a JDK or JRE are the same in my case. (1.8) According to this stack overflow post it would appear that I need to be using java 1.8, so I'm not sure what the problem is:

如何修复java.lang.UnsupportedClassVersionError:不支持的major.minor版本

我已采取的步骤

我确保我的pom.xml文件引用了Java 1.8.在intellij中:在编译器设置下，我将目标字节码版本设置为1.8.在Maven设置下，导入程序的JDK和运行程序一样都设置为Java 1.8.在项目结构中，项目SDK设置为Java 1.8，项目语言级别设置为8.我还检查了java.com，并确认Internet Explorer中运行的Java版本与我的JDK和JRE相同.我还确保计算机上的PATH变量指向正确的JDK.作为一个黑暗的镜头，我还尝试将所有引用更改为使用Java 1.7，但在部署后仍然出现相同的错误.

I made sure my pom.xml file references java 1.8. In intellij: under Compiler settings I set the target bytecode version is 1.8. Under Maven settings the JDK for importer is set to java 1.8, as is the runner. In project structure the project SDK is set to java 1.8 and the project language level is set to 8. I've also checked java.com and confirmed that version of java running in internet explorer is the same version 1.8 as my JDK and JRE. I have also made sure that my PATH variable on my computer is pointing to the correct JDK. As a shot in the dark, I also tried changing all of the references to use java 1.7, but still got the same error after deploying.

在下面，我列出了我的pom.xml文件和错误的堆栈跟踪.一如既往，感谢您的时间和帮助！

Below I've listed my pom.xml file and the stack trace for the error. As always, thanks for the time and assistance!

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.projectName.project</groupId>
    <artifactId>Project</artifactId>
    <packaging>war</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>Test Maven Webapp</name>
    <url>http://maven.apache.org</url>

    <properties>
        <org.springframework.version>4.0.6.RELEASE</org.springframework.version>
        <hibernate.version>5.2.1.Final</hibernate.version>
        <mysql.connector.version>5.5.49</mysql.connector.version>
        <hibernate.version>5.2.1.Final</hibernate.version>
        <mysql.connector.version>5.5.50</mysql.connector.version>

    </properties>

    <dependencies>
        <!-- JDBC Driver -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>6.0.3</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>

        <!-- Spring -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${org.springframework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${org.springframework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${org.springframework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${org.springframework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>1.10.2.RELEASE</version>
        </dependency>

        <!-- Hibernate -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.1.1.Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.0-api</artifactId>
            <version>1.0.1.Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>5.1.1.Final</version>
        </dependency>

        <!-- HSQL Database -->
        <dependency>
            <groupId>org.hsqldb</groupId>
            <artifactId>hsqldb</artifactId>
            <version>2.3.2</version>
        </dependency>

        <!-- JSON -->
        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20160810</version>
        </dependency>

        <!-- Jackson To Convert java to JSON -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.8.1</version>
        </dependency>

        <!-- Application View -->
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>


        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>2.0</version>
        </dependency>

        <!-- Log4J -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>

    <build>
        <finalName>ROOT</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>

                <version>2.5.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <configuration>
                    <webXml>src\main\webapp\WEB-INF\web.xml</webXml>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

堆栈跟踪

type Exception report

message Servlet.init() for servlet springDispatcherServlet threw exception

description The server encountered an internal error that prevented it from fulfilling this request.

exception
javax.servlet.ServletException: Servlet.init() for servlet springDispatcherServlet threw exception
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1502)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1458)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Thread.java:724)


root cause 

java.lang.UnsupportedClassVersionError: springmvc/controllers/AccountController : Unsupported major.minor version 52.0 (unable to load class springmvc.controllers.AccountController)
org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2506)
org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:831)
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1274)
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1139)
org.springframework.util.ClassUtils.forName(ClassUtils.java:247)
org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:395)
org.springframework.beans.factory.support.AbstractBeanFactory.doResolveBeanClass(AbstractBeanFactory.java:1346)
org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1317)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:594)
org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1394)
org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:385)
org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:362)
org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:348)
org.springframework.context.support.AbstractApplicationContext.getBeanNamesForType(AbstractApplicationContext.java:1051)
org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.initHandlerMethods(AbstractHandlerMethodMapping.java:119)
org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.afterPropertiesSet(AbstractHandlerMethodMapping.java:103)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.afterPropertiesSet(RequestMappingHandlerMapping.java:126)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1612)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1549)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:703)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:658)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:624)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:672)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:543)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:484)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
javax.servlet.GenericServlet.init(GenericServlet.java:158)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1502)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1458)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Thread.java:724)

推荐答案

UnsupportedClassVersionError 始终为 ，原因是该类是使用大于Java版本的Java版本编译的.用于运行它的Java版本.

UnsupportedClassVersionError is always due to the fact that a class was compiled with a Java version greater than the Java version being used to run it.

当您拥有一个 IDE ，一个像 Tomcat 之类的应用服务器以及其他东西时，您可能具有一些必须指向 JDK 的设置.(其中 JAVA_HOME 环境变量是最重要的).如果它们都指向正确的位置，那没有问题，但是可能会出现诸如以下的错误:

When you have an IDE, an app server like Tomcat and other things, you may have several settings that must point to a JDK (with the JAVA_HOME environment variable being the most important). If they all point to the correct place, there's no problem, however there are possibilities for errors such as:

• 将设置点设置为 JRE 而不是 JDK

当需要 JRE 中不存在的 javac 时，这会导致问题.例如， Tomcat 需要 javac 进行编译，因此 JRE 是不够的.

This causes problems when there's a need for javac which doesn't exist in the JRE. For example Tomcat needs javac to compile things, so JRE is not enough.

• 设置指向与其他设置不同的 JDK

这会导致 UnsupportedClassVersionError ，然后您需要查找哪个设置错误. JAVA_HOME 通常指向正确的位置，但是其他设置则指向较旧的 JDK .常见的问题是 JAVA_HOME 指向Oracle的JDK，而Tomcat指向 OpenJDK .

This causes the UnsupportedClassVersionError, and then you need to find which setting is wrong. Often JAVA_HOME points to the correct place, but a different setting points to an older JDK. A common problem is having JAVA_HOME point to Oracle's JDK and Tomcat pointing to OpenJDK.

由于可以使用 -source 和 -target 标志为较早的版本进行编译，因此您无需在系统上保留多个JDK.删除旧的错误，神秘错误的机会就会减少.

Since you can use -source and -target flags to compile for older versions, you don't need to keep more than one JDK on your system. Remove the old ones and the chances for mysterious errors diminish.

这篇关于修复java.lang.UnsupportedClassVersionError的问题:不支持的major.minor版本52的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！