Nexus搭建私服的过程

    最近准备使用Jenkins+gitlab+nexus做CI，终于要用到之前就想搭建却耽搁了许久的Nexus，今天上午终于成功的deploy上了一个测试的jar，今天记录一下过程。（Windows上进行的安装，版本为3.9）

    Nexus是一个maven私服工具，它提供了便捷的管理界面，功能强大。

1、 下载、安装、运行Nexus

　　Windows免安装版：链接: https://pan.baidu.com/s/11Ya6rvNG7x8U1ypGjL-xBA 提取码: 56jm。直接解压，然后把nexus中bin的路径配置成环境变量，cmd中运行nexus.exe /run，即可运行。

       网站地址为http://localhost:8081，登录名：admin，密码：admin123。

2、 配置仓库

   　

　　Nexus上会有几个类型的仓库，分别是：Hosted，proxy，group。hosted代表本地仓库，即私服自己的仓库（这也是私服和远程仓库的区别，私服可以在本地存储构件和jar）；proxy是远程仓库的代理；group是组的概念，它可以把几个仓库绑定到一起，maven的settings.xml配置只需要添加这一个组就能引用组内的所有仓库。

       Nexus上会有默认的几个仓库，release、snapshots、central、group，这几个就是对应的上面的仓库类型，不同的release和snapshots两个仓库都是hosted类型的，区别是release是稳定版本，snapshots是快照版本。这个在本地代码进行deploy时会很明显的发现区别。

       Nexus已经为我们配置好了这些仓库，只需要修改一下maven-central的remote storage，改成一个国内的maven镜像（这边使用的aliyun）。

3、 settings.xml配置

　　配置如下：

<?xml version="1.0" encoding="UTF-8"?>

<!--
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
-->

<!--
 | This is the configuration file for Maven. It can be specified at two levels:
 |
 |  1. User Level. This settings.xml file provides configuration for a single user,
 |                 and is normally provided in ${user.home}/.m2/settings.xml.
 |
 |                 NOTE: This location can be overridden with the CLI option:
 |
 |                 -s /path/to/user/settings.xml
 |
 |  2. Global Level. This settings.xml file provides configuration for all Maven
 |                 users on a machine (assuming they're all using the same Maven
 |                 installation). It's normally provided in
 |                 ${maven.home}/conf/settings.xml.
 |
 |                 NOTE: This location can be overridden with the CLI option:
 |
 |                 -gs /path/to/global/settings.xml
 |
 | The sections in this sample file are intended to give you a running start at
 | getting the most out of your Maven installation. Where appropriate, the default
 | values (values used when the setting is not specified) are provided.
 |
 |-->
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">
  <!-- localRepository
   | The path to the local repository maven will use to store artifacts.
   |
   | Default: ${user.home}/.m2/repository
    -->
  <localRepository>D:javamaven-local
epository</localRepository>
 

  <!-- interactiveMode
   | This will determine whether maven prompts you when it needs input. If set to false,
   | maven will use a sensible default value, perhaps based on some other setting, for
   | the parameter in question.
   |
   | Default: true
  <interactiveMode>true</interactiveMode>
  -->

  <!-- offline
   | Determines whether maven should attempt to connect to the network when executing a build.
   | This will have an effect on artifact downloads, artifact deployment, and others.
   |
   | Default: false
  <offline>false</offline>
  -->

  <!-- pluginGroups
   | This is a list of additional group identifiers that will be searched when resolving plugins by their prefix, i.e.
   | when invoking a command line like "mvn prefix:goal". Maven will automatically add the group identifiers
   | "org.apache.maven.plugins" and "org.codehaus.mojo" if these are not already contained in the list.
   |-->
  <pluginGroups>
    <!-- pluginGroup
     | Specifies a further group identifier to use for plugin lookup.
    <pluginGroup>com.your.plugins</pluginGroup>
    -->      
	<pluginGroup>org.apache.maven.plugins</pluginGroup>
  </pluginGroups>

  <!-- proxies
   | This is a list of proxies which can be used on this machine to connect to the network.
   | Unless otherwise specified (by system property or command-line switch), the first proxy
   | specification in this list marked as active will be used.
   |-->
  <proxies>
    <!-- proxy
     | Specification for one proxy, to be used in connecting to the network.
     |
    <proxy>
      <id>optional</id>
      <active>true</active>
      <protocol>http</protocol>
      <username>proxyuser</username>
      <password>proxypass</password>
      <host>proxy.host.net</host>
      <port>80</port>
      <nonProxyHosts>local.net|some.host.com</nonProxyHosts>
    </proxy>
    -->
  </proxies>

  <!-- servers
   | This is a list of authentication profiles, keyed by the server-id used within the system.
   | Authentication profiles can be used whenever maven must make a connection to a remote server.
   |-->
  <servers>
    <!-- server
     | Specifies the authentication information to use when connecting to a particular server, identified by
     | a unique name within the system (referred to by the 'id' attribute below).
     |
     | NOTE: You should either specify username/password OR privateKey/passphrase, since these pairings are
     |       used together.
     |
     -->
    <server>
      <id>release</id>
      <username>admin</username>
      <password>admin123</password>
    </server>
    
    <server>
      <id>snapshots</id>
      <username>admin</username>
      <password>admin123</password>
    </server>
    
    

    <!-- Another sample, using keys to authenticate.
    <server>
      <id>release</id>
      <privateKey>/path/to/private/key</privateKey>
      <passphrase>optional; leave empty if not used.</passphrase>
    </server>
    -->
  </servers>

  <!-- mirrors
   | This is a list of mirrors to be used in downloading artifacts from remote repositories.
   |
   | It works like this: a POM may declare a repository to use in resolving certain artifacts.
   | However, this repository may have problems with heavy traffic at times, so people have mirrored
   | it to several places.
   |
   | That repository definition will have a unique id, so we can create a mirror reference for that
   | repository, to be used as an alternate download site. The mirror site will be the preferred
   | server for that repository.
   |-->
  <mirrors>
    <!-- mirror
     | Specifies a repository mirror site to use instead of a given repository. The repository that
     | this mirror serves has an ID that matches the mirrorOf element of this mirror. IDs are used
     | for inheritance and direct lookup purposes, and must be unique across the set of mirrors.
     |
    <mirror>
      <id>mirrorId</id>
      <mirrorOf>repositoryId</mirrorOf>
      <name>Human Readable Name for this Mirror.</name>
      <url>http://my.repository.com/repo/path</url>
    </mirror>
     -->
	<mirror>
      <id>local-mirror</id>
      <mirrorOf>*</mirrorOf>
      <name>local-mirror</name>
      <url>http://127.0.0.1:8081/repository/maven-public/</url>
    </mirror>
  </mirrors>

  <!-- profiles
   | This is a list of profiles which can be activated in a variety of ways, and which can modify
   | the build process. Profiles provided in the settings.xml are intended to provide local machine-
   | specific paths and repository locations which allow the build to work in the local environment.
   |
   | For example, if you have an integration testing plugin - like cactus - that needs to know where
   | your Tomcat instance is installed, you can provide a variable here such that the variable is
   | dereferenced during the build process to configure the cactus plugin.
   |
   | As noted above, profiles can be activated in a variety of ways. One way - the activeProfiles
   | section of this document (settings.xml) - will be discussed later. Another way essentially
   | relies on the detection of a system property, either matching a particular value for the property,
   | or merely testing its existence. Profiles can also be activated by JDK version prefix, where a
   | value of '1.4' might activate a profile when the build is executed on a JDK version of '1.4.2_07'.
   | Finally, the list of active profiles can be specified directly from the command line.
   |
   | NOTE: For profiles defined in the settings.xml, you are restricted to specifying only artifact
   |       repositories, plugin repositories, and free-form properties to be used as configuration
   |       variables for plugins in the POM.
   |
   |-->
  <profiles>
    <!-- profile
     | Specifies a set of introductions to the build process, to be activated using one or more of the
     | mechanisms described above. For inheritance purposes, and to activate profiles via <activatedProfiles/>
     | or the command line, profiles have to have an ID that is unique.
     |
     | An encouraged best practice for profile identification is to use a consistent naming convention
     | for profiles, such as 'env-dev', 'env-test', 'env-production', 'user-jdcasey', 'user-brett', etc.
     | This will make it more intuitive to understand what the set of introduced profiles is attempting
     | to accomplish, particularly when you only have a list of profile id's for debug.
     |
     | This profile example uses the JDK version to trigger activation, and provides a JDK-specific repo.
    <profile>
      <id>jdk-1.4</id>

      <activation>
        <jdk>1.4</jdk>
      </activation>

      <repositories>
        <repository>
          <id>jdk14</id>
          <name>Repository for JDK 1.4 builds</name>
          <url>http://www.myhost.com/maven/jdk14</url>
          <layout>default</layout>
          <snapshotPolicy>always</snapshotPolicy>
        </repository>
      </repositories>
    </profile>
    -->

    <!--
     | Here is another profile, activated by the system property 'target-env' with a value of 'dev',
     | which provides a specific path to the Tomcat instance. To use this, your plugin configuration
     | might hypothetically look like:
     |
     | ...
     | <plugin>
     |   <groupId>org.myco.myplugins</groupId>
     |   <artifactId>myplugin</artifactId>
     |
     |   <configuration>
     |     <tomcatLocation>${tomcatPath}</tomcatLocation>
     |   </configuration>
     | </plugin>
     | ...
     |
     | NOTE: If you just wanted to inject this configuration whenever someone set 'target-env' to
     |       anything, you could just leave off the <value/> inside the activation-property.
     |
    
    <profile>
      <id>env-dev</id>

      <activation>
        <property>
          <name>target-env</name>
          <value>dev</value>
        </property>
      </activation>

    </profile>
    -->
    
     <profile>
      <id>default_profile</id>
      <repositories>
        <!--包含需要连接到远程仓库的信息 -->
        <repository>
          <!--远程仓库唯一标识 -->
          <id>localRepository</id>
          <!--远程仓库名称 -->
          <name>localRepository</name>
          <!--如何处理远程仓库里发布版本的下载 -->
          <releases>
            <!--true或者false表示该仓库是否为下载某种类型构件（发布版，快照版）开启。 -->
            <enabled>true</enabled>
            <!--该元素指定更新发生的频率。Maven会比较本地POM和远程POM的时间戳。这里的选项是：always（一直），daily（默认，每日），interval：X（这里X是以分钟为单位的时间间隔），或者never（从不）。 -->
            <updatePolicy>never</updatePolicy>
            <!--当Maven验证构件校验文件失败时该怎么做-ignore（忽略），fail（失败），或者warn（警告）。 -->
            <checksumPolicy>warn</checksumPolicy>
          </releases>
          <!--如何处理远程仓库里快照版本的下载。有了releases和snapshots这两组配置，POM就可以在每个单独的仓库中，为每种类型的构件采取不同的策略。例如，可能有人会决定只为开发目的开启对快照版本下载的支持。参见repositories/repository/releases元素 -->
          <snapshots>
            <!--true或者false表示该仓库是否为下载某种类型构件（发布版，快照版）开启。 -->
            <enabled>true</enabled>
            <!--该元素指定更新发生的频率。Maven会比较本地POM和远程POM的时间戳。这里的选项是：always（一直），daily（默认，每日），interval：X（这里X是以分钟为单位的时间间隔），或者never（从不）。 -->
            <updatePolicy>always</updatePolicy>
            <!--当Maven验证构件校验文件失败时该怎么做-ignore（忽略），fail（失败），或者warn（警告）。 -->
            <checksumPolicy>warn</checksumPolicy>
          </snapshots>
          <!--远程仓库URL，按protocol://hostname/path形式 -->
          <url>http://127.0.0.1:8081/repository/maven-public/</url>
          <!--用于定位和排序构件的仓库布局类型-可以是default（默认）或者legacy（遗留）。Maven 2为其仓库提供了一个默认的布局；然而，Maven 1.x有一种不同的布局。我们可以使用该元素指定布局是default（默认）还是legacy（遗留）。 -->
          <layout>default</layout>
        </repository>
      </repositories>
      
      <pluginRepositories>  
        <pluginRepository>  
          <id>maven-net-cn</id>  
          <name>maven-en</name>  
          <url>http://127.0.0.1:8081/repository/maven-public/</url>  
          <releases>  
            <enabled>true</enabled>  
          </releases>  
          <snapshots>  
            <enabled>true</enabled>  
          </snapshots>      
        </pluginRepository>  
      </pluginRepositories> 
  
    </profile>
  </profiles>

  <!-- activeProfiles
   | List of profiles that are active for all builds.
   -->
  <activeProfiles>
    <activeProfile>default_profile</activeProfile>
  </activeProfiles>

</settings>

4、 项目配置

　　新建maven项目，配置本地的maven地址，配置maven和settings.xml（步骤省略），然后就可以开始愉快的开发了。

5、 项目deploy

　　如果需要deploy安装jar包的话，还需要在项目pom.xml文件中加入

<distributionManagement>
        <repository>
            <id>release</id>
            <name>release</name>
            <url>http://127.0.0.1:8081/repository/maven-releases/</url>
        </repository>
        <snapshotRepository>
            <id>snapshots</id>
            <name>snapshots</name>
            <url>http://127.0.0.1:8081/repository/maven-snapshots/</url>
        </snapshotRepository>
    </distributionManagement>

　　注意：url是仓库的url，id需要和settings.xml中<severs>配置的用户密码对应的id相同。

6、 其他：

　　1） 无法下载plugins相关的jar包：需要在settings.xml的<pluginGroups>标签中加入<pluginGroup>org.apache.maven.plugins</pluginGroup>，然后把.lastUpload的文件都删除掉，重新reimport。

　　2） deploy报错：首先检查配置是否有问题，都没问题还是失败的话，可以敲命令行：mvn deploy -s d://java//maven//settings.xml（-s后面跟上settings.xml的文件路径）。