Online Baidu Search a heap of solutions, are not what to use, and finally solved their own. So share the ending method:
Error Reason:
HTTP 503 error, is the problem that the server is not a problem with the code.
My problem here is that your project may be in the post and you open the page directly causing the error.
It may also be the result of a JDK error.
The solution is simple, rude and quick:
(i) whether to use the JBoss server or the Tomcat server, publish the item currently, first check the project's JDK environment variable configuration pairing is not. If they're all paired up. So the next step.
(b) If you are using Tomcat server, delete the WebApps item below Tomcat, then republish the project in Eclipse, and then open the project. OK, successfully solved the problem open the Web page normally.
If you are using JBoss server, then redistribute the project directly, restart once, successfully resolved, will not eject.
Summary: First check the environment configuration, and then check the project published there is no error. Reboot again and solve it successfully.