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我已经阅读了我能找到的所有关于这个的帖子，但我似乎无法克服这个错误来让我的 maven spring mvc web 应用程序正常工作。当我访问 localhost 或我的控制器中指定的任何 URI 时，我只会得到 HTTP 状态 500。

据我了解，问题的出现是因为编译时使用的 JDK 比运行时使用的高。但在我看来，对 JDK 或 JRE 的所有引用在我的情况下都是相同的。（1.8）根据this stack overflow post看来我需要使用java 1.8，所以我不确定问题是什么：

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 设置为 java 1.8，运行程序也是如此。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 并确认在 Internet Explorer 中运行的 java 版本与我的 JDK 和 JRE 版本相同 1.8。我还确保我计算机上的 PATH 变量指向正确的 JDK。作为一个在黑暗中的镜头，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。

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！

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)
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1 回答 1

2

UnsupportedClassVersionError总是因为一个类是用比运行它的 Java 版本更高的 Java 版本编译的。

当你有一个IDE、一个应用服务器之类的Tomcat东西时，你可能有几个必须指向 a 的设置JDK（JAVA_HOME环境变量是最重要的）。如果它们都指向正确的位置，则没有问题，但是可能会出现错误，例如：

  • 将点设置为JRE而不是JDK

当. javac_ JRE比如Tomcat需要javac编译东西，这样JRE是不够的。

  • 将点设置为不同于JDK其他设置

这会导致UnsupportedClassVersionError, 然后你需要找出哪个设置是错误的。通常JAVA_HOME指向正确的位置，但不同的设置指向较旧的JDK. 一个常见的问题是JAVA_HOME指向 Oracle 的 JDK 和 Tomcat 指向OpenJDK.

由于您可以使用-source和-target标志为旧版本进行编译，因此您不需要在系统上保留多个 JDK。删除旧的，神秘错误的机会减少。

于 2016-09-03T15:07:16.177 回答