jenkins upgrade after error

• After upgrading, Jenkins doesn’t start: org.xml.sax.saxparseexception: premature end of file
• How to fix java.lang.UnsupportedClassVersionError: Unsupported major.minor version
• CentOS JDK 설치

jenkins.log 확인

tail -f /var/log/jenkins/jenkins.log
...

경고: Failed startup of context w.@19f37d14{/,file:/var/cache/jenkins/war/,STARTING}{/var/cache/jenkins/war}
java.lang.reflect.InvocationTargetException
	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.eclipse.jetty.webapp.IterativeDescriptorProcessor.visit(IterativeDescriptorProcessor.java:85)
	at org.eclipse.jetty.webapp.IterativeDescriptorProcessor.process(IterativeDescriptorProcessor.java:72)
	at org.eclipse.jetty.webapp.MetaData.resolve(MetaData.java:408)
	at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1340)
	at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:741)
	at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:505)
	at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
	at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
	at org.eclipse.jetty.server.Server.start(Server.java:387)
	at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
	at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)
	at org.eclipse.jetty.server.Server.doStart(Server.java:354)
	at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
	at winstone.Launcher.(Launcher.java:152)
	at winstone.Launcher.main(Launcher.java:352)
	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 Main._main(Main.java:264)
	at Main.main(Main.java:112)
Caused by: java.lang.UnsupportedClassVersionError: jenkins/util/SystemProperties : Unsupported major.minor version 52.0
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:803)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:442)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:64)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:354)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:348)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:347)
	at org.eclipse.jetty.webapp.WebAppClassLoader.findClass(WebAppClassLoader.java:510)
	at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:441)
	at org.eclipse.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:403)
	at org.eclipse.jetty.server.handler.ContextHandler.loadClass(ContextHandler.java:1583)
	at org.eclipse.jetty.webapp.StandardDescriptorProcessor.visitListener(StandardDescriptorProcessor.java:1956)
	... 25 more

Caused by: java.lang.UnsupportedClassVersionError: jenkins/util/SystemProperties : Unsupported major.minor version 52.0
자바 버전 확인 후 버전 업데이트 필요

# JRE 버전 확인이 필요
Java SE 9 = 53,
Java SE 8 = 52,
Java SE 7 = 51,
Java SE 6.0 = 50,
Java SE 5.0 = 49,
JDK 1.4 = 48,
JDK 1.3 = 47,
JDK 1.2 = 46,
JDK 1.1 = 45

# 버전확인
java -version
java version "1.7.0_131"
OpenJDK Runtime Environment (rhel-2.6.9.0.el6_8-x86_64 u131-b00)
OpenJDK 64-Bit Server VM (build 24.131-b00, mixed mode)

# 설치 가능 확인
yum list java*jdk-devel
# 1.8 설치
yum install java-1.8.0-openjdk-devel.x86_64


# 버전 확인
java -version
openjdk version "1.8.0_121"
OpenJDK Runtime Environment (build 1.8.0_121-b13)
OpenJDK 64-Bit Server VM (build 25.121-b13, mixed mode)