maven install 把jar包放到WEB-INFO下面
在pom.xml里加上

<plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-dependency-plugin</artifactId><version>2.1</version><executions><execution><id>copy</id><phase>package</phase><goals><goal>copy-dependencies</goal></goals><configuration><outputDirectory>src/main/webapp/WEB-INF/lib</outputDirectory><stripVersion>false</stripVersion></configuration></execution></executions></plugin>

运行maven install 可以拷贝jar包到WEB-INFO/lib下面