maven shade plugin: Invalid signature file digest for Manifest main attributes

If you get the following error message with maven shade plugin:

Exception in thread "main" java.lang.SecurityException: Invalid signature file digest for Manifest main attributes

You need to add the following to pom.xml:

        <configuration>
          <filters>
            <filter>
              <artifact>*:*</artifact>
              <excludes>
                <exclude>META-INF/*.SF</exclude>
                <exclude>META-INF/*.DSA</exclude>
                <exclude>META-INF/*.RSA</exclude>
              </excludes>
            </filter>
          </filters>
        </configuration>

Explanation:

The above configuration filters all files in META-INF ending with .SF, .DSA, and .RSA for all artifacts (*:*) when creating uber-jar file.

The reason java.lang.SecurityException is raised is because some dependency jar files are signed jar files.  A jar file is signed by using jarsigner, which creates 2 additional files and places them in META-INF:

• a signature file, with a .SF extension, and
• a signature block file, with a .DSA, .RSA, or .EC extension.

Since the uber-jar file is created, the signatures and integrity of signed JAR files are no longer valid.  When the uber-jar file is executed, java.lang.SecurityException is thrown.

See jarsigner for detailed explanation of JAR Signing and Verification Tool.