需要更改的有三处: 
1.tomcat的配置:在conf\tomcat-users.xml中加上有管理权限的用户: 
<?xml version='1.0' encoding='utf-8'?>   
<tomcat-users>   
  <role rolename="manager"/>   
  <user username="marshal" password="password" roles="manager"/>   
</tomcat-users>  

2.在pox.xml中添加 
plugin>   
    <groupId>org.codehaus.mojo</groupId>   
    <artifactId>tomcat-maven-plugin</artifactId>   
    <configuration>   
        <url>http://localhost:8080/manager</url>   
        <server>tomcat.server</server>   
        <path>/mycontext</path>   
    </configuration>   
</plugin> 

3.在.m2/settings.xml文件中增加: 
<settings xmlns="http://maven.apache.org/POM/4.0.0"  
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0   
http://maven.apache.org/xsd/settings-1.0.0.xsd">   
        <servers>   
                <server>   
                        <id>tomcat.server</id>   
                        <username>marshal</username>   
                        <password>password</password>   
                </server>   
        </servers>   
</settings>  
注意:红色的要一致,username和password要一致,<url>要配置上服务器的url</url>