在用Eclipse+Tomcat配置J2EE项目时，出现如下提示错误：
Undeployment Failure could not be redeployed because it could not be completely removed in the undeployment phase. the most common cuase 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.
最终解决方法如下：
1、停止运行Tomcat，右键点击项目名称：
2、点击“Properties”，在弹出窗口选中“Java Build Path”，再点“Libraries”书签，如下图
3、把所有项目的jar都Remove掉，然后再把这个项目的jar都加进来，
4、添加完后，再次Redeploy，
5、看到Successfully deplayed，即配置成功了。如上图。
Tomcat Deployment failure ，locked one or more files
原文：http://www.cnblogs.com/henuyuxiang/p/6674877.html