Read manifest from JAR with gradle

Jürgen :

how it is possible to read the manifest from a jar dependency in gradle? I whant to print out this information

I didn'f find a solution for that.

Best regards

Francisco Mateo :

It is possible. Here's a quick example I came up with using the Kotlin DSL:

dependencies {
    implementation("org.apache.commons:commons-lang3:3.9")
}

val readManifest by tasks.registering {
    doLast {
        val archive = configurations["compileClasspath"].filter {
            // This will be list of resolved jars, so filter on the jar name.
            it.name.startsWith("commons-lang3")
        }
        val version = resources.text.fromArchiveEntry(archive, "META-INF/MANIFEST.MF")
        println(version.asString())
    }
}

Output of the task is:

> Task :readManifest
Manifest-Version: 1.0
Created-By: Apache Maven Bundle Plugin
Built-By: chtompki
Build-Jdk: 11.0.2
Specification-Title: Apache Commons Lang
Specification-Version: 3.9
Specification-Vendor: The Apache Software Foundation
Implementation-Title: Apache Commons Lang
Implementation-Version: 3.9
Implementation-Vendor-Id: org.apache.commons
Implementation-Vendor: The Apache Software Foundation
Implementation-URL: http://commons.apache.org/proper/commons-lang/
Automatic-Module-Name: org.apache.commons.lang3
Bnd-LastModified: 1554946229157
Bundle-Description: Apache Commons Lang, a package of Java utility class
 es for the  classes that are in java.lang's hierarchy, or are considere
 d to be so  standard as to justify existence in java.lang.
Bundle-DocURL: http://commons.apache.org/proper/commons-lang/
Bundle-License: https://www.apache.org/licenses/LICENSE-2.0.txt
Bundle-ManifestVersion: 2
Bundle-Name: Apache Commons Lang
Bundle-SymbolicName: org.apache.commons.lang3
Bundle-Vendor: The Apache Software Foundation
Bundle-Version: 3.9.0
Export-Package: org.apache.commons.lang3;version="3.9",org.apache.common
 s.lang3.arch;version="3.9",org.apache.commons.lang3.builder;version="3.
 9",org.apache.commons.lang3.concurrent;version="3.9",org.apache.commons
 .lang3.event;version="3.9",org.apache.commons.lang3.exception;version="
 3.9",org.apache.commons.lang3.math;version="3.9",org.apache.commons.lan
 g3.mutable;version="3.9",org.apache.commons.lang3.reflect;version="3.9"
 ,org.apache.commons.lang3.text;version="3.9",org.apache.commons.lang3.t
 ext.translate;version="3.9",org.apache.commons.lang3.time;version="3.9"
 ,org.apache.commons.lang3.tuple;version="3.9"
Include-Resource: META-INF/NOTICE.txt=NOTICE.txt,META-INF/LICENSE.txt=LI
 CENSE.txt
Require-Capability: osgi.ee;filter:="(&(osgi.ee=JavaSE)(version=1.8))"
Tool: Bnd-4.1.0.201810181252

The implementation configuration is not resolvable, so the compileClasspath is used instead since it is resolvable. You can see the configuration tree here