Method 1: You need to delete the signature file META-INF in the apk package (change the apk format to the compressed package format, delete the META-INF folder, and change it back. Apk format);

Copy the certificate (debug.keystore) to the directory where the apk file needs to be re-signed (for example, copy it to d: \ sign);

Enter cmd mode and enter the D:\Sign directory;

Run the following command jarsigner-verbose-keystordebug.keystore-storesandroid-signed jar phonebook _ signed.apk-digest algsha1-sigalgmd5 with RSA phonebook. K.apk androidbugkey/* Explanation: -jarsigner is a signature tool of Java -verbose parameter means: display signature details -Keystore means to sign the certificate file with debug.Keystore in the current directory -storepass android means keystore password: "Android "- signed jar phonebook _ signed. . APK represents the name PhoneBook.apk generated after signature. APK stands for unsigned APK Android software-Digest Algsha1-SigmaMD5 with RSA: This is a parameter that must be added, and it will not be affected if you are jdk 1.6 -AndroidBugKey stands for key alias.

You're finished. Look at the folder.

Method 2: use the tool re-sign.jar to open re-sign.jar and delete the signature file META-INF, then drag apk to re-sign.jar and click Save;