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.
可能是架包错误 ， 解决办法
1、停止运行Tomcat，右键点击项目， 选择点击“Properties”，在弹出窗口选中“Java Build Path”，再点“Libraries”书签，如下图
2。 如果有错误的架包 ，删除 或者查看原因 解决错误 ，再次redeployed ，
如还不行 ，就删除所有jar 包 ，从 webapps中的web-inf 的lib 从新导入jar 包