I've spent far too much time trying to figure this out. This should be the simplest thing and everyone who distributes Java applications in jars must have to deal with it.
I just want to know the proper way to add versioning to my Java app so that
I can access the version information when
I'm testing, e.g. debugging in Eclipse and running from a jar.
Here's what
I have in my
build.xml:
<target name="jar" depends = "compile">
<property name="version.num" value="1.0.0"/>
<buildnumber file="
build.num"/>
<tstamp>
<format property="TODAY" pattern="yyyy-MM-dd HH:mm:ss" />
</tstamp>
<manifest file="${build}/META-INF/MANIFEST.MF">
<attribute name="Built-By" value="${user.name}" />
<attribute name="Built-Date" value="${TODAY}" />
<attribute name="Implementation-Title" value="MyApp" />
<attribute name="Implementation-Vendor" value="MyCompany" />
<attribute name="Implementation-Version" value="${version.num}-b${build.number}"/>
</manifest>
<jar destfile="${build}/myapp.jar" basedir="${build}" excludes="*.jar" />
</target>
This creates /META-INF/MANIFEST.MF and
I can read the values when
I'm debugging in Eclipse thusly:
public MyClass()
{
try
{
InputStream stream = getClass().getResourceAsStream("/META-INF/MANIFEST.MF");
Manifest manifest = new Manifest(stream);
Attributes attributes = manifest.getMainAttributes();
String implementationTitle = attributes.getValue("Implementation-Title");
String implementationVersion = attributes.getValue("Implementation-Version");
String builtDate = attributes.getValue("Built-Date");
String builtBy = attributes.getValue("Built-By");
}
catch (IOException e)
{
logger.error("Couldn't read manifest.");
}
}
But, when
I create the jar file, it loads the manifest of another jar (presumably the first jar loaded by the application - in my case, activation.jar).
Also, the following code doesn't work either although all the proper values are in the manifest file.
Package thisPackage = getClass().getPackage();
String implementationVersion = thisPackage.getImplementationVersion();
Any ideas?
