转：http://www.th7.cn/Program/java/201408/269316.shtml
Nexus启动报错： Unsupported major.minor version 51.0
1.遇到问题
今天搭建Nexus私服，出现了以前没遇到过的错误。
a).采用console-nexus.bat开启报错：
wrapper| --> Wrapper Started as Consolewrapper| Launching a JVM...jvm 1| java.lang.UnsupportedClassVersionError: org/sonatype/nexus/bootstrap/jsw/JswLauncher : Unsupported major.minor version 51.0jvm 1|at java.lang.ClassLoader.defineClass1(Native Method)jvm 1|at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)jvm 1|at java.lang.ClassLoader.defineClass(ClassLoader.java:615)jvm 1|at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)jvm 1|at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)jvm 1|at java.net.URLClassLoader.access$000(URLClassLoader.java:58)jvm 1|at java.net.URLClassLoader$1.run(URLClassLoader.java:197)jvm 1|at java.security.AccessController.doPrivileged(Native Method)jvm 1|at java.net.URLClassLoader.findClass(URLClassLoader.java:190)jvm 1|at java.lang.ClassLoader.loadClass(ClassLoader.java:306)jvm 1|at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)jvm 1|at java.lang.ClassLoader.loadClass(ClassLoader.java:247)jvm 1| Could not find the main class: org.sonatype.nexus.bootstrap.jsw.JswLauncher.Program will exit.jvm 1| Exception in thread "main"wrapper| JVM exited while loading the application.wrapper| Reloading Wrapper configuration...wrapper| Launching a JVM...
b).采用install-nexus.bat、start-nexus.bat开启报错：
wrapper| Starting the nexus service...wrapper| Waiting to start...wrapper| Waiting to start...wrapper| Waiting to start...wrapper| The nexus service was launched, but failed to start.
2.分析问题
看日志的问题，大概就是版本存在问题，找不到Java虚拟机。
Java版本：1.6.0_45
Nexus版本： 2.7.2-03
按照网上的办法是修改bin/jsw/conf/wrapper.conf中的wrapper.java.command
wrapper.java.command=C:/Lynch/Develop/Java/jdk1.6/bin/java.exe
指向自己的jdk，似乎在特俗的Nexus版本可以解决，这里我还是不行。
3.解决问题
最终查询文档得到思路
Sonatype Nexus 2.6.0Java 6 Support EOLOracle‘s support for Java 6 ended in February 2013.Consequentially as of version 2.6 Nexus now requires a Java 7 JRE to run.
Sonatype Nexus OSS 2.5.0Java 6 Support is DeprecatedJava 6 reached Official EOL on February 2013.Since it is no longer receiving updates we are deprecating support for running Nexus with Java 6 in the 2.5 release, and will be removing it in the upcoming 2.6 release.
Sonatype Nexus 2.0 Release NotesJDK 7 SupportNexus 2.0 is the first version of Nexus verified to work with Java 7. The recommended versions areOracle 7u2 or later *IBM Java 7.0 GA or later* Note: Nexus 2.0 will not run on versions of Oracle Java 7 prior to 7u2.When running with Java 6 the recommended versions are:Oracle Java 6u30 or laterIBM Java 6.0.10.0 or Later
a).Nexus的2.6版本及其以后版本
使用的Java的jdk7.
b).Nexus的2.0-2.5版本
使用Java的jdk6的update30版本及其以后的jdk6版本
使用Java的jdk7的update2版本及其以后jdk7版本
c).最终解决方案
升级jdk7（注意jdk的update版本，升级最新版本就可以）
4.参考文档
https://support.sonatype.com/entries/23150053-Sonatype-Nexus-Release-Notes?__utma=246996102.1501838135.1395215985.1395815367.1395822104.4&__utmb=246996102.21.9.1395822181403&__utmc=246996102&__utmx=-&__utmz=246996102.1395822104.4.4.utmcsr=google|utmccn=(organic)|utmcmd=organic|utmctr=(not%20provided)&__utmv=-&__utmk=14901813