Eclispe change webapp name

Motivation. There are some step you can change your web app in eclispe

Step:
 1. open project
 2. click the mouse right button and choose the properties in the finally button
 3. choose  web project setting
 4. type the new in context root
 5. stop the server and remove the old project
 6. because the eclipse will change the web.xml file, and add the tag in   web.xml, so 1. you can copy old web.xml to this.  2. or delete this tag 


Encourage problem but can solve by my step especially the step 6 is important:
a. problem {java.lang.IllegalArgumentException: Can't convert}
b. 404 not find new appname


Eclipse store your  web application position:
/home/${yourname}/workspace2/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps


Reference:
How to change eclipse webapp name?
How to fix the error of java.lang.IllegalArgumentException: Can't convert