I'm so careless I deleted a Java web project in eclipse. the only thing I have is a war file which I got from server.
Thanks to Procyon / Java Decompiler, I recovered all java source code from war class file. It's really a great tool!
You can download it from https://bitbucket.org/mstrobel/procyon/downloads
then execute following command to decompile class files in to current directory.
java -jar procyon-decompiler-0.5.27.jar *.class -o .
For spring MVC project, it cannot recover @Autowried annotation, you have to add it manually.