错误信息：
项目名称 could not be redeployed because it could not be completely removed inthe undeployment phase. The most common cause of this problem is attempting to redeploy while the server is running,which has locked one or more files.
To correct the deployment you will need to stop the server and then redeploy the project before restarting the server.
出现该问题的原因是：
项目根目录下的.classpath文件中引用的.jar文件与项目中的.jar不一致。
解决方法：
将.classpath文件中的classpathentry属性引用的.jar文件和项目lib文件夹中的.jar文件进行对比。修正不存在的的.jar文件引用和补齐未引用的。再重新部署就OK了。
MyEclipse 项目部署到tomcat时出现错误之——deploy
原文：http://my.oschina.net/dailongyao/blog/337090