JDK Jarsigner：jar是无符号的。 （签名丢失或无法解析）

Question

我与JDK签约：1.8 jarsigner。 使用JDK验证结果：1.8：

C:\glassfish4\jdk8\bin\jarsigner -verify sample_sha1_sha1.jar -verbose

  Timestamped by "***" on Wed Jun 06 17:59:57 UTC 2018
    Timestamp digest algorithm: SHA-1
    Timestamp signature algorithm: SHA256withRSA, 2048-bit key

jar verified.

但是当我用JDK验证时，同样签名的jar：1.7_21_b11，它表示jar无符号。 结果：

C:\glassfish4\jdk7\bin\jarsigner -verify sample_sha1_sha1.jar -verbose

         898 Wed Jun 06 17:59:56 IST 2018 META-INF/MANIFEST.MF
 m       172 Wed Nov 16 18:45:40 IST 2016 META-INF/NOTICE
 m     10351 Wed Nov 16 18:45:40 IST 2016 META-INF/LICENSE

  s = signature was verified
  m = entry is listed in manifest
  k = at least one certificate was found in keystore
  i = at least one certificate was found in identity scope

jar is unsigned. (signatures missing or not parsable)

请帮我解决这个问题。