TomCAT error msg "FAIL - Application at context path /app could not be started"

tomcat seems not able to copy .war to deploy correctly. After deploy, if you check .war content, you will find it still use old version of .war file. So you have to manually copy your .war file to webapps/ and unrar it. Here is how to do it

1. suppose you have aa.war at somewhere/
2. mkdir aa
3. cd aa
4. jar -xvf aa.war
5. cd webapps
6.cp -r somewhere/aa .
7. restart tomcat

I just found another faster way to do it. In eclipse, when exporting war file, directly select the tomcat webapps dir. The tomcat will automatically deploy it, so you don’t need to use tomcat manager to deploy