Mohammed, You should be importing the war file into a Web project not a Java project. However, I don't think that is related to the problem.
To isolate the problem, you can see if the server starts up without anything on it. To do this, add the server view to your perspective, right click the server and select start.
If the server starts up fine, we need to figure out what is wrong with your workspace. If the server does not start up, there is either something wrong with your install or the server profile got corrupted. You can "uncorrupt" it by deleting the profile and creating a new one.