下载并启动Jenkins报错

按教程下载了jenkins.war 文件，然后用 java -jar jenkins.war ，启动报错

用的jdk7

警告: Failed startup of context w.@58342475{/,file:/C:/Users/admin/.jenkins/war/,STARTING}{C:\Users\admin\.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.<init>(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:800)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
        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


七月 10, 2017 4:46:44 下午 org.eclipse.jetty.util.log.JavaUtilLog info
信息: Started ServerConnector@37bc2b18{HTTP/1.1}{0.0.0.0:8080}
七月 10, 2017 4:46:44 下午 org.eclipse.jetty.util.log.JavaUtilLog info
信息: Started @1037ms
七月 10, 2017 4:46:44 下午 winstone.Logger logInternal
信息: Winstone Servlet Engine v2.0 running: controlPort=disabled

有传言说说因为Jdk 版本问题，搜到的帖子：http://www.cnblogs.com/xing901022/p/4172410.html

1 J2SE 7 = 51 (0x33 hex),2 J2SE 6.0 = 50 (0x32 hex),3 J2SE 5.0 = 49 (0x31 hex),4 JDK 1.4 = 48 (0x30 hex),5 JDK 1.3 = 47 (0x2F hex),6 JDK 1.2 = 46 (0x2E hex),7 JDK 1.1 = 45 (0x2D hex).

然后换了jdk8, 果然问题就好了，