当构建Maven项目时，首先检查pom.xml文件以确定依赖包的下载位置，执行顺序如下：
1、从本地资源库中查找并获得依赖包，如果没有，执行第2步。
2、从Maven默认中央仓库中查找并获得依赖包（http://repo1.maven.org/maven2/），如果没有，执行第3步。
3、如果在pom.xml中自定义的远程仓库，那么也会在这里的仓库中进行查找并获得依赖包，如果都没有找到，那么Maven就会抛出异常。
<!-- 设定远程主仓库，按设定顺序进行查找。 -->
<repositories> <!-- 如有Nexus私服, 取消注释并指向正确的服务器地址.
<repository>
<id>nexus-repos</id>
<name>Team Nexus Repository</name>
<url>http://192.168.11.36:8888/nexus/content/groups/public</url>
</repository> --> <repository>
<id>oschina-repos</id>
<name>Oschina Releases</name>
<url>http://maven.oschina.net/content/groups/public</url>
</repository> <repository>
<id>aliyun-repos</id>
<name>aliyun Releases</name>
<url>http://maven.aliyun.com/nexus/content/groups/public/</url>
</repository> <repository>
<id>java-repos</id>
<name>Java Repository</name>
<url>https://maven.java.net/content/repositories/public/</url>
</repository> <repository>
<id>JBoss-repos</id>
<name>JBoss Repository</name>
<url>http://repository.jboss.org/nexus/content/groups/public/</url>
</repository> <repository>
<id>springsource-repos</id>
<name>SpringSource Repository</name>
<url>http://repo.spring.io/release/</url>
</repository> <repository>
<id>central-repos</id>
<name>Central Repository</name>
<url>http://repo.maven.apache.org/maven2</url>
</repository> <repository>
<id>central-repos2</id>
<name>Central Repository 2</name>
<url>http://repo1.maven.org/maven2/</url>
</repository> <repository>
<id>activiti-repos</id>
<name>Activiti Repository</name>
<url>https://maven.alfresco.com/nexus/content/groups/public</url>
</repository> <repository>
<id>activiti-repos2</id>
<name>Activiti Repository 2</name>
<url>https://app.camunda.com/nexus/content/groups/public</url>
</repository> <repository>
<id>easonjim-repos</id>
<name>EasonJim Repository</name>
<url>https://raw.github.com/easonjim/repository/master</url>
</repository> </repositories>
