一个签名过名的jar包，解压后修改里面一张图片，用java命令还原回去，报错、高手帮忙！

[一切为了个人信息化]

General:
An error occurred while launching/running the application.

Title: Contact Center Anywhere
Vendor: Oracle
Category: Download Error

Could not verify signing in resource: http://192.168.1.112/cca/plugins/com.taw.cca.client.app.common_8.1.2.39.jar

Exception:
JNLPException[category: Download Error : Exception: java.lang.SecurityException: SHA1 digest error for common.jar : LaunchDesc: null ]
at com.sun.javaws.security.SigningInfo.checkSigning(Unknown Source)
at com.sun.javaws.cache.DownloadProtocol$RetrieveAction.actionDownload(Unknown Source)
at com.sun.javaws.cache.DownloadProtocol.doDownload(Unknown Source)
at com.sun.javaws.cache.DownloadProtocol.getResource(Unknown Source)
at com.sun.javaws.LaunchDownload.downloadJarFiles(Unknown Source)
at com.sun.javaws.LaunchDownload.downloadEagerorAll(Unknown Source)
at com.sun.javaws.Launcher.downloadResources(Unknown Source)
at com.sun.javaws.Launcher.handleApplicationDesc(Unknown Source)
at com.sun.javaws.Launcher.handleLaunchFile(Unknown Source)
at com.sun.javaws.Launcher.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

Wrapped Exception:
java.lang.SecurityException: SHA1 digest error for common.jar
at sun.security.util.ManifestEntryVerifier.verify(Unknown Source)
at java.util.jar.JarVerifier.processEntry(Unknown Source)
at java.util.jar.JarVerifier.update(Unknown Source)
at java.util.jar.JarVerifier$VerifierStream.read(Unknown Source)
at com.sun.javaws.security.SigningInfo.checkSigning(Unknown Source)
at com.sun.javaws.cache.DownloadProtocol$RetrieveAction.actionDownload(Unknown Source)
at com.sun.javaws.cache.DownloadProtocol.doDownload(Unknown Source)
at com.sun.javaws.cache.DownloadProtocol.getResource(Unknown Source)
at com.sun.javaws.LaunchDownload.downloadJarFiles(Unknown Source)
at com.sun.javaws.LaunchDownload.downloadEagerorAll(Unknown Source)
at com.sun.javaws.Launcher.downloadResources(Unknown Source)
at com.sun.javaws.Launcher.handleApplicationDesc(Unknown Source)
at com.sun.javaws.Launcher.handleLaunchFile(Unknown Source)
at com.sun.javaws.Launcher.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

[ChDw]

这个不是废话吗，如果你可以随意修改，还叫签名？？

签名的意义在于防止其他用户修改！你只能重新签名

[一切为了个人信息化]

您能告诉我，如何重新签名？重新签名，是不是其它的所有jar包都需要重新签名呢？