每次打包成jar还要再用命令处理太麻烦了，写了个批处理。

@echo off
f:
cd F:/Java/OnlineTalk/OnlineTalk
jar -xvf OnlineTalk.jar
del OnlineTalk.jar
cd META-INF
del SUN_MICR.RSA
del SUN_MICR.SF
cd ../
jar -cvfm OnlineTalk.jar META-INF/MANIFEST.MF *

详见：
http://blog.csdn.net/ruanruoshi/archive/2006/06/06/776429.aspx