java.lang.UnsupportedClassVersionError

Recently, when using jdk8 to build a project for technical practice, the following error message appears when starting:

"C:\Program Files\Java_plugs\apache-tomcat-8.5.23\bin\catalina.bat" run
[2017-12-19 11:06:51,048] Artifact freemarker:war exploded: Server is not connected. Deploy is not available.
Using CATALINA_BASE:   "C:\Users\vip\.IntelliJIdea14\system\tomcat\Unnamed_freemarker"
Using CATALINA_HOME:   "C:\Program Files\Java_plugs\apache-tomcat-8.5.23"
Using CATALINA_TMPDIR: "C:\Program Files\Java_plugs\apache-tomcat-8.5.23\temp"
Using JRE_HOME:        "C:\Program Files\Java\jdk1.7.0_75"
Using CLASSPATH:       "C:\Program Files\Java_plugs\apache-tomcat-8.5.23\bin\bootstrap.jar;C:\Program Files\Java_plugs\apache-tomcat-8.5.23\bin\tomcat-juli.jar"
19-Dec-2017 11:06:53.482 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Server version:        Apache Tomcat/8.5.23
19-Dec-2017 11:06:53.485 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Server built:          Sep 28 2017 10:30:11 UTC
19-Dec-2017 11:06:53.485 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Server number:         8.5.23.0
19-Dec-2017 11:06:53.486 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log OS Name:               Windows 7
19-Dec-2017 11:06:53.486 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log OS Version:            6.1
19-Dec-2017 11:06:53.486 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Architecture:          amd64
19-Dec-2017 11:06:53.486 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Java Home:             C:\Program Files\Java\jdk1.7.0_75\jre
19-Dec-2017 11:06:53.486 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Version:           1.7.0_75-b13
19-Dec-2017 11:06:53.486 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log JVM Vendor:            Oracle Corporation
19-Dec-2017 11:06:53.486 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_BASE:         C:\Users\vip\.IntelliJIdea14\system\tomcat\Unnamed_freemarker
19-Dec-2017 11:06:53.487 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log CATALINA_HOME:         C:\Program Files\Java_plugs\apache-tomcat-8.5.23
19-Dec-2017 11:06:53.487 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.config.file=C:\Users\vip\.IntelliJIdea14\system\tomcat\Unnamed_freemarker\conf\logging.properties
19-Dec-2017 11:06:53.487 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
19-Dec-2017 11:06:53.487 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote=
19-Dec-2017 11:06:53.487 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote.port=1099
19-Dec-2017 11:06:53.488 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote.ssl=false
19-Dec-2017 11:06:53.488 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcom.sun.management.jmxremote.authenticate=false
19-Dec-2017 11:06:53.488 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.rmi.server.hostname=127.0.0.1
19-Dec-2017 11:06:53.488 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djdk.tls.ephemeralDHKeySize=2048
19-Dec-2017 11:06:53.488 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.protocol.handler.pkgs=org.apache.catalina.webresources
19-Dec-2017 11:06:53.488 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.base=C:\Users\vip\.IntelliJIdea14\system\tomcat\Unnamed_freemarker
19-Dec-2017 11:06:53.488 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Dcatalina.home=C:\Program Files\Java_plugs\apache-tomcat-8.5.23
19-Dec-2017 11:06:53.488 信息 [main] org.apache.catalina.startup.VersionLoggerListener.log Command line argument: -Djava.io.tmpdir=C:\Program Files\Java_plugs\apache-tomcat-8.5.23\temp
19-Dec-2017 11:06:53.489 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent Loaded APR based Apache Tomcat Native library [1.2.14] using APR version [1.6.2].
19-Dec-2017 11:06:53.489 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].
19-Dec-2017 11:06:53.489 信息 [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent APR/OpenSSL configuration: useAprConnector [false], useOpenSSL [true]
19-Dec-2017 11:06:54.322 信息 [main] org.apache.catalina.core.AprLifecycleListener.initializeSSL OpenSSL successfully initialized [OpenSSL 1.0.2l  25 May 2017]
19-Dec-2017 11:06:54.505 信息 [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["http-nio-8080"]
19-Dec-2017 11:06:54.537 信息 [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
19-Dec-2017 11:06:54.542 信息 [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["ajp-nio-8009"]
19-Dec-2017 11:06:54.551 信息 [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
19-Dec-2017 11:06:54.552 信息 [main] org.apache.catalina.startup.Catalina.load Initialization processed in 1604 ms
19-Dec-2017 11:06:54.607 信息 [main] org.apache.catalina.core.StandardService.startInternal Starting service [Catalina]
19-Dec-2017 11:06:54.607 信息 [main] org.apache.catalina.core.StandardEngine.startInternal Starting Servlet Engine: Apache Tomcat/8.5.23
19-Dec-2017 11:06:54.623 信息 [main] org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ["http-nio-8080"]
19-Dec-2017 11:06:54.642 信息 [main] org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ["ajp-nio-8009"]
19-Dec-2017 11:06:54.650 信息 [main] org.apache.catalina.startup.Catalina.start Server startup in 97 ms
[2017-12-19 11:06:54,681] Artifact freemarker:war exploded: Artifact is being deployed, please wait...
Connected to server
19-Dec-2017 11:06:55.108 严重 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ContainerBase.addChildInternal ContainerBase.addChild: start: 
 org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:752)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
	at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1739)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
	at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
	at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:482)
	at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:431)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
	at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
	at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1487)
	at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:97)
	at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1328)
	at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1420)
	at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:848)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322)
	at sun.rmi.transport.Transport$2.run(Transport.java:202)
	at sun.rmi.transport.Transport$2.run(Transport.java:199)
	at java.security.AccessController.doPrivileged(Native Method)
	at sun.rmi.transport.Transport.serviceCall(Transport.java:198)
	at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:567)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:828)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.access$400(TCPTransport.java:619)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$1.run(TCPTransport.java:684)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$1.run(TCPTransport.java:681)
	at java.security.AccessController.doPrivileged(Native Method)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:681)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.UnsupportedClassVersionError: org/springframework/web/SpringServletContainerInitializer : Unsupported major.minor version 52.0 (unable to load class [org.springframework.web.SpringServletContainerInitializer])
	at org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2288)
	at org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:811)
	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1260)
	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:274)
	at org.apache.catalina.startup.WebappServiceLoader.loadServices(WebappServiceLoader.java:188)
	at org.apache.catalina.startup.WebappServiceLoader.load(WebappServiceLoader.java:159)
	at org.apache.catalina.startup.ContextConfig.processServletContainerInitializers(ContextConfig.java:1622)
	at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1135)
	at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:775)
	at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:299)
	at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:94)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5105)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	... 44 more

19-Dec-2017 11:06:55.115 严重 [RMI TCP Connection(3)-127.0.0.1] org.apache.tomcat.util.modeler.BaseModelMBean.invoke Exception invoking method manageApp
 java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:756)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
	at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1739)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
	at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
	at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:482)
	at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:431)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
	at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
	at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1487)
[2017-12-19 11:06:55,157] Artifact freemarker:war exploded: Error during artifact deployment. See server log for details.
	at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:97)
	at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1328)
	at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1420)
	at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:848)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322)
	at sun.rmi.transport.Transport$2.run(Transport.java:202)
	at sun.rmi.transport.Transport$2.run(Transport.java:199)
	at java.security.AccessController.doPrivileged(Native Method)
	at sun.rmi.transport.Transport.serviceCall(Transport.java:198)
	at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:567)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:828)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.access$400(TCPTransport.java:619)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$1.run(TCPTransport.java:684)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$1.run(TCPTransport.java:681)
	at java.security.AccessController.doPrivileged(Native Method)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:681)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)

19-Dec-2017 11:06:55.115 严重 [RMI TCP Connection(3)-127.0.0.1] org.apache.tomcat.util.modeler.BaseModelMBean.invoke Exception invoking method createStandardContext
 javax.management.RuntimeOperationsException: Exception invoking method manageApp
	at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:308)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
	at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
	at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:482)
	at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:431)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
	at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
	at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1487)
	at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:97)
	at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1328)
	at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1420)
	at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:848)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322)
	at sun.rmi.transport.Transport$2.run(Transport.java:202)
	at sun.rmi.transport.Transport$2.run(Transport.java:199)
	at java.security.AccessController.doPrivileged(Native Method)
	at sun.rmi.transport.Transport.serviceCall(Transport.java:198)
	at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:567)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:828)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.access$400(TCPTransport.java:619)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$1.run(TCPTransport.java:684)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$1.run(TCPTransport.java:681)
	at java.security.AccessController.doPrivileged(Native Method)
	at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:681)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:756)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
	at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1739)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
	... 35 more

The key information is:

Caused by: java.lang.UnsupportedClassVersionError: org/springframework/web/SpringServletContainerInitializer : Unsupported major.minor version 52.0 (unable to load class [org.springframework.web.SpringServletContainerInitializer])

The reaction is that version 52.0 is not supported when running. Many people may be confused. What is 52.0?Let me show you the introduction of Oracle official website

J2SE 9 = 53

J2SE 8 = 52

J2SE 7 = 51

J2SE 6.0 = 50

J2SE 5.0 = 49

JDK 1.4 = 48

JDK 1.3 = 47

JDK 1.2 = 46

JDK 1.1 = 45

You should understand that 52 corresponds to the version of jdk8. I use jdk8 for development, but it is not supported when I run it, because I run it with JRE. I read the log of Tomcat when I start the next time

Using CATALINA_BASE:   "C:\Users\vip\.IntelliJIdea14\system\tomcat\Unnamed_freemarker"
Using CATALINA_HOME:   "C:\Program Files\Java_plugs\apache-tomcat-8.5.23"
Using CATALINA_TMPDIR: "C:\Program Files\Java_plugs\apache-tomcat-8.5.23\temp"
Using JRE_HOME:        "C:\Program Files\Java\jdk1.7.0_75"
Using CLASSPATH:       "C:\Program Files\Java_plugs\apache-tomcat-8.5.23\bin\bootstrap.jar;C:\Program Files\Java_plugs\apache-tomcat-8.5.23\bin\tomcat-juli.jar"

This actually uses the version of jre1.7 to run. All you need to do is change the JRE used at runtime.

Next, I will introduce the key points of idea tool inspection

If you are using eclipse, just check the log carefully to see which version of JRE and Tomcat information it is

DebugAH

How to Solve Your Programmer Error

Tag Archives: java.lang.UnsupportedClassVersionError

java.lang.UnsupportedClassVersionError:Unsupported major.minor version 52.0