How can app read its own Manifest.mf file ?

[swebb99]

Hi,

If I run an application from a jar how do I get a handle on the
standard Manifest file so I can read it.

It appears that there is a JarInputStream that can be used to get hold
of the Manifest Object but I'm not sure how I actually get a handle on
a stream for the correct jar file. I know a class file that is always
in the jar so I assume I can in someway use this to get hold of the
jar file being used and then open a stream to it ????

Any idea's ?

Thanks

Steve

 

[Alan Krueger]

It appears that there is a JarInputStream that can be used to get hold
of the Manifest Object but I'm not sure how I actually get a handle on
a stream for the correct jar file. I know a class file that is always
in the jar so I assume I can in someway use this to get hold of the
jar file being used and then open a stream to it ????

Take a look at the Class.getProtectionDomain,
ProtectionDomain.getCodeSource, and CodeSource.getLocation methods and
see if those help.

 

[swebb99]

Take a look at the Class.getProtectionDomain,
ProtectionDomain.getCodeSource, and CodeSource.getLocation methods and
see if those help.

Thanks Alan,

I had a look at some previous load resource code I wrote and it also
used the protection domain. Anyway I ended up using this code which
works for both standalone code from a JAR and WebStart code from a
JAR. Its rough by the way just to see if it works I realise it needs
tweaking


final ProtectionDomain domain =
agentsupport.class.getProtectionDomain();
final CodeSource source = domain.getCodeSource();
URL url = source.getLocation();
if(url.toExternalForm().endsWith(".jar")) {
try {
JarInputStream jarStream = new JarInputStream(url.openStream(),
false);
Attributes attr = jarStream.getManifest().getMainAttributes();
Set set = attr.entrySet();
if(set != null) {
log.info("Manifest Attributes :");
Iterator it = set.iterator();
while(it.hasNext()) {
Map.Entry entry = (Map.Entry)it.next();
log.info(entry.getKey() + ": " + entry.getValue());
}
}

} catch (IOException e) {
}
}


The only problem I hit was when reading the Manifest from WebStart I
use the Maven 1.1 JNLP plugin and it dumps over the original Manifest
and offers no properties to define what should go in there Bugger