1、首先下载nexus，下载地址是http://www.sonatype.org/nexus/go，在此页面可以下载最新版本的Nexus;
2、解压下载的zip包，安装Nexus，由于下载的zip包自带jetty,在cmd命令模式下 到Nexus的安装目录，执行命令nexus.bat install命令安装nexus
3、然后运行nexus.bat start命令启动nexus（其他命令有nexus.bat stop停止 nexus.bat restart重启 nexus.bat uninstall卸载）
在浏览器地址栏输入http://localhost:8080/nexus/即进入nexus首页。有管理nexus要以管理员身份登录，点击首页右上角的login输入默认登录名、密码admin/admin123即可登录。
登录系统后点击左侧菜单栏Views/Repositories下的Repositories选择Central仓库点击下边的Configuration把Download Remote Indexes属性设为True保存即可。
然后在Central仓库上右键然后点击Repair Index 即可下载中心仓库的索引文件，稍等几分钟点击下边的Browse Index即可看见下载的索引文件。
往Public Repositories中添加Central仓库，点击Public Repositories在Configuration选项卡中把Central移到左侧即可。
最后在自己的应用中把中心仓库配置成建立的私有仓库地址即可，修改本地的maven配置文件，C:\Documents and Settings\用户名\.m2\setting.xml
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 Console
wrapper | Launching a JVM...
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | java.lang.UnsupportedClassVersionError: org/sonatype/nexus/bootstrap/
jsw/JswLauncher : Unsupported major.minor version <span class="number" style="color: rgb(0, 153, 153);">51.0</span>
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at java.lang.ClassLoader.defineClass1(Native Method)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at java.lang.ClassLoader.defineClassCond(ClassLoader.java:<span class="number" style="color: rgb(0, 153, 153);">631</span>)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at java.lang.ClassLoader.defineClass(ClassLoader.java:<span class="number" style="color: rgb(0, 153, 153);">615</span>)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at java.security.SecureClassLoader.defineClass(SecureClassLoader
.java:<span class="number" style="color: rgb(0, 153, 153);">141</span>)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at java.net.URLClassLoader.defineClass(URLClassLoader.java:<span class="number" style="color: rgb(0, 153, 153);">283</span>)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at java.net.URLClassLoader.access<span class="variable" style="color: rgb(0, 128, 128);">$0</span>0<span class="number" style="color: rgb(0, 153, 153);">0</span>(URLClassLoader.java:<span class="number" style="color: rgb(0, 153, 153);">58</span>)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at java.net.URLClassLoader<span class="variable" style="color: rgb(0, 128, 128);">$1</span>.run(URLClassLoader.java:<span class="number" style="color: rgb(0, 153, 153);">197</span>)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at java.security.AccessController.doPrivileged(Native Method)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at java.net.URLClassLoader.findClass(URLClassLoader.java:<span class="number" style="color: rgb(0, 153, 153);">190</span>)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at java.lang.ClassLoader.loadClass(ClassLoader.java:<span class="number" style="color: rgb(0, 153, 153);">306</span>)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at sun.misc.Launcher<span class="variable" style="color: rgb(0, 128, 128);">$AppClassLoader</span>.loadClass(Launcher.java:<span class="number" style="color: rgb(0, 153, 153);">301</span>)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | at java.lang.ClassLoader.loadClass(ClassLoader.java:<span class="number" style="color: rgb(0, 153, 153);">247</span>)
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | Could <span class="keyword" style="font-weight: bold;">not</span> find the main class: org.sonatype.nexus.bootstrap.jsw.JswLa
uncher. Program will <span class="keyword" style="font-weight: bold;">exit</span>.
jvm <span class="number" style="color: rgb(0, 153, 153);">1</span> | Exception in thread <span class="string" style="color: rgb(221, 17, 68);">"main"</span>
wrapper | JVM exited <span class="keyword" style="font-weight: bold;">while</span> 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 <span class="operator"><span class="keyword" style="font-weight: bold;">start</span>...
wrapper | Waiting <span class="keyword" style="font-weight: bold;">to</span> <span class="keyword" style="font-weight: bold;">start</span>...
wrapper | Waiting <span class="keyword" style="font-weight: bold;">to</span> <span class="keyword" style="font-weight: bold;">start</span>...
wrapper | The nexus service was launched, but failed <span class="keyword" style="font-weight: bold;">to</span> <span class="keyword" style="font-weight: bold;">start</span>.</span>
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 2.6.0
Java 6 Support EOL
Oracle'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 <span class="number" style="color: rgb(0, 153, 153);">2.5</span><span class="number" style="color: rgb(0, 153, 153);">.0</span>Java <span class="number" style="color: rgb(0, 153, 153);">6</span> Support <span class="keyword" style="font-weight: bold;">is</span> DeprecatedJava <span class="number" style="color: rgb(0, 153, 153);">6</span> reached Official EOL on February <span class="number" style="color: rgb(0, 153, 153);">2013.</span> Since it <span class="keyword" style="font-weight: bold;">is</span> no longer receiving updates we are deprecating support <span class="keyword" style="font-weight: bold;">for</span> running Nexus <span class="keyword" style="font-weight: bold;">with</span> Java <span class="number" style="color: rgb(0, 153, 153);">6</span> <span class="keyword" style="font-weight: bold;">in</span> the <span class="number" style="color: rgb(0, 153, 153);">2.5</span> release, <span class="keyword" style="font-weight: bold;">and</span> will be removing it <span class="keyword" style="font-weight: bold;">in</span> the upcoming <span class="number" style="color: rgb(0, 153, 153);">2.6</span> release.
Sonatype Nexus <span class="number" style="color: rgb(0, 153, 153);">2.0</span> Release NotesJDK <span class="number" style="color: rgb(0, 153, 153);">7</span> SupportNexus <span class="number" style="color: rgb(0, 153, 153);">2.0</span> <span class="keyword" style="font-weight: bold;">is</span> the first version of Nexus verified to work <span class="keyword" style="font-weight: bold;">with</span> Java <span class="number" style="color: rgb(0, 153, 153);">7.</span> The recommended versions areOracle <span class="number" style="color: rgb(0, 153, 153);">7</span>u2 <span class="keyword" style="font-weight: bold;">or</span> later *IBM Java <span class="number" style="color: rgb(0, 153, 153);">7.0</span> GA <span class="keyword" style="font-weight: bold;">or</span> later* Note: Nexus <span class="number" style="color: rgb(0, 153, 153);">2.0</span> will <span class="keyword" style="font-weight: bold;">not</span> run on versions of Oracle Java <span class="number" style="color: rgb(0, 153, 153);">7</span> prior to <span class="number" style="color: rgb(0, 153, 153);">7</span>u2.When running <span class="keyword" style="font-weight: bold;">with</span> Java <span class="number" style="color: rgb(0, 153, 153);">6</span> the recommended versions are:Oracle Java <span class="number" style="color: rgb(0, 153, 153);">6</span>u30 <span class="keyword" style="font-weight: bold;">or</span> laterIBM Java <span class="number" style="color: rgb(0, 153, 153);">6.0</span><span class="number" style="color: rgb(0, 153, 153);">.10</span><span class="number" style="color: rgb(0, 153, 153);">.0</span> <span class="keyword" style="font-weight: bold;">or</span> 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）