tomcat不支持的major.minor版本52.0 [重复]

Question

这个问题在这里已有答案：

• How to fix java.lang.UnsupportedClassVersionError: Unsupported major.minor version 48回答
• Unsupported major.minor version 52.0 [duplicate] 26回答

我试图运行示例https://github.com/thymeleaf/thymeleafexamples-springmail

当我运行mvn tomcat7:run

得到以下错误。不确定什么是不兼容的版本？我附上了pom.xml的详细信息。想知道这是否是由于我的java版本与maven或tomcat不兼容造成的？

严重：启动期间子容器失败java.util.concurrent.ExecutionException：org.apache.catalina.LifecycleException：无法在java.util启动组件[StandardEngine [Tomcat] .StandardHost [localhost] .StandardContext [/ springmail]]。并发.TutureTask.report（FutureTask.java:122）位于org.apache.catalina.core.ContainerBase.startInternal（ContainerBase.java:1123）的java.util.concurrent.FutureTask.get（FutureTask.java:188） .apache.catalina.core.StandardHost.startInternal（StandardHost.java:800）org.apache.catalina.util.LifecycleBase.start（LifecycleBase.java:150）at org.apache.catalina.core.ContainerBase $ StartChild.call （ContainerBase.java:1559）位于java.util的java.util.concurrent.FutureTask.run（FutureTask.java:262）的org.apache.catalina.core.ContainerBase $ StartChild.call（ContainerBase.java:1549）。 concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:1145）at java.util.concurrent.ThreadPoolExecutor $ Worker.run（ThreadPoolExecutor.java:615）at java.lang.Thread.run （Thread.java:745）引起：org.apache.catalina.LifecycleException：无法在org.apache.catalina.util.LifecycleBase中启动组件[StandardEngine [Tomcat] .StandardHost [localhost] .StandardContext [/ springmail]]。 start（LifecycleBase.java:154）... 6更多引起：java.lang.UnsupportedClassVersionError：org / springframework / web / SpringServletContainerInitializer：java上java.lang.ClassLoader.defineClass1（Native Method）中不支持的major.minor版本52.0 .lang.ClassLoader.defineClass（ClassLoader.java:800）位于java.net.URLClassLlass的java.net.URLClassLoader.defineClass（URLClassLoader.java:449）中的java.security.SecureClassLoader.defineClass（SecureClassLoader.java:142）。 java.net.URLClassLoader $ 1.run（URLClassLoader.java:351）java.net.URLClassLoader $ 1.run（URLClassLoader.java:355）java.security.AccessController.doPrivileged访问$ 100（URLClassLoader.java:71） Native.net）在java.net.URLClassLoader.findClass（URLClassLoader.java:354）org.apache.catalina.loader.WebappClassLo位于org.apache.catalina.loader.WebappClassLoader.loadClass（WebappClassLoader.java:1669）的ader.findClass（WebappClassLoader.java:1191）位于org.apache.catalina.loader.WebappClassLoader.loadClass（WebappClassLoader.java:1547）的java位于org.apache.catalina的org.apache.catalina.startup.ContextConfig.getServletContainerInitializer（ContextConfig.java:1668）java.lang.Class.forName（Class.java:270）的.lang.Class.forName0（Native Method） .startup.ContextConfig.getServletContainerInitializers（ContextConfig.java:1652）org.apache.catalina.startup.ContextConfig.processServletContainerInitializers（ContextConfig.java:1562）at org.apache.catalina.startup.ContextConfig.webConfig（ContextConfig.java:1270 ）org.apache.catalina.startup.ContextConfig.configureStart（ContextConfig.java:878）org.apache.catalina.startup.ContextConfig.lifecycleEvent（ContextConfig.java:376）org.apache.catalina.util.LifecycleSupport。 fireLifecycleEvent（LifecycleSupport.java:119）org.apache.catalina.util.LifecycleBase.fireLi fecycleEvent（LifecycleBase.java:90）org.apache.catalina.core.StandardContext.startInternal（StandardContext.java:5322）org.apache.catalina.util.LifecycleBase.start（LifecycleBase.java:150）... 6更多

<properties>
        <maven.compile.source>1.6</maven.compile.source>
        <maven.compile.target>1.6</maven.compile.target>
        <project.build.sourceEncoding>US-ASCII</project.build.sourceEncoding>
        <thymeleaf.version>3.0.11.RELEASE</thymeleaf.version>
        <springframework.version>5.1.0.RELEASE</springframework.version>
    </properties>

  <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.0</version>
                <configuration>
                  <source>${maven.compile.source}</source>
                  <target>${maven.compile.target}</target>
                  <encoding>${project.build.sourceEncoding}</encoding>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>3.1.0</version>
                <configuration>
                  <encoding>${project.build.sourceEncoding}</encoding>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.2.2</version>
                <configuration>
                  <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <version>2.2</version>
            </plugin>
  <dependency>
            <groupId>org.thymeleaf</groupId>
            <artifactId>thymeleaf</artifactId>
            <version>${thymeleaf.version}</version>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>org.thymeleaf</groupId>
            <artifactId>thymeleaf-spring5</artifactId>
            <version>${thymeleaf.version}</version>
            <scope>compile</scope>
        </dependency>

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

        <dependency>
        <groupId>commons-digester</groupId>
        <artifactId>commons-digester</artifactId>
        <version>2.1</version>
        </dependency>

        <dependency>
        <groupId>commons-logging</groupId>
        <artifactId>commons-logging</artifactId>
        <version>1.2</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${springframework.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${springframework.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${springframework.version}</version>
        </dependency>

        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.1</version>
        </dependency>

        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.4</version>
        </dependency>

        <dependency>
            <groupId>javax.mail</groupId>
            <artifactId>mail</artifactId>
            <version>1.4.7</version>
        </dependency>

        <!--
        // FIXME: why does not work with 
        <dependency>
            <groupId>javax.mail</groupId>
            <artifactId>javax.mail-api</artifactId>
            <version>1.5.2</version>
        </dependency>-->

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.25</version>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.25</version>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
            <scope>compile</scope>
            <exclusions>
                <exclusion>
                    <groupId>com.sun.jdmk</groupId>
                    <artifactId>jmxtools</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.sun.jmx</groupId>
                    <artifactId>jmxri</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>javax.jms</groupId>
                    <artifactId>jms</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

    </dependencies>

Answer 1

问题是您使用的JRE早于版本8运行Tomcat实例。

Tomcat可能使用环境变量JAVA_HOME / JRE_HOME指向JRE。 看看它现在指向的位置。