in src/main/java/org/apache/maven/plugins/artifact/buildinfo/ReferenceBuildinfoUtil.java [202:217]
private ReproducibleEnv extractEnv(File file, Artifact artifact) {
log.debug("Guessing java.version and os.name from jar " + file);
try (JarFile jar = new JarFile(file)) {
Manifest manifest = jar.getManifest();
if (manifest != null) {
String javaVersion = extractJavaVersion(manifest);
String osName = extractOsName(artifact, jar);
return new ReproducibleEnv(javaVersion, osName);
} else {
log.warn("no MANIFEST.MF found in jar " + file);
}
} catch (IOException e) {
log.warn("unable to open jar file " + file, e);
}
return null;
}