Jarsigner in JDK7 uses SHA256 by default, which is safer?

Therefore, the signature operation in JDK7 will not be installed (I wonder if this is to tell Google that the certificate verification mechanism in your mobile phone is going to be updated? ), which can be found in jarsigner.

Add the following parameters to the signing command to solve the problem:

-digestalg SHA 1 -sigalg

MD5withRSA and jdk7 do not support empty group sorting. If you plan to upgrade, the old program may have a lot of problems waiting for you.

So if you plan to upgrade JDK7, please fully grasp it!