Showing build time, version etc in web apps and desktop applications

It is quite convenient to be able to show Application Version and build time in any given java program. Below is my way of doing this. 

Ant script for War Files 

<target name="-post-dist">      
        <!-- Empty placeholder for easier customization. -->
        <!--<property file="build.properties"/>-->
        <buildnumber file="build.version"/>
        <tstamp>
            <format property="timestamp" pattern="yyyy-MM-dd HH:mm:ss"/>
        </tstamp>
            <jar destfile="${dist.war}" update="true">
     
        <manifest>
            <attribute name="Manifest-Version" value="1.0" />        
            <attribute name="Created-By" value="Me" />        
            <attribute name="Bundle" value="${build.number}"/>
            <attribute name="Bundle-Date" value="${timestamp}" />
        </manifest>
        </jar>
        <!-- You can override this target in the ../build.xml file. -->
 </target>

Java Code for Web Application 

 public static String getBuildNumberAndDateFromWar(WebServiceContext context){
        String buildNumber="";
        try {
            javax.xml.ws.handler.MessageContext mc = context.getMessageContext();
            HttpServletRequest req = (HttpServletRequest) mc.get(javax.xml.ws.handler.MessageContext.SERVLET_REQUEST);
            InputStream stream = req.getServletContext().getResourceAsStream("/META-INF/MANIFEST.MF");
            Manifest manifest = new Manifest(stream);
            Attributes attributes = manifest.getMainAttributes();
            String bundle = attributes.getValue("Bundle");
            String bundle_date = attributes.getValue("Bundle-Date");
            stream.close();
            if (bundle!=null && !"null".equals(bundle))
                buildNumber = " [bundle:"+ bundle + ", date:" + bundle_date+"] ";

        } catch (Exception e) {
            e.printStackTrace();
        }
        return buildNumber;
    }

Ant Script for Jar file

 <target name="-post-jar">
        <!-- Empty placeholder for easier customization. -->
        <!-- You can override this target in the ../build.xml file. -->
        <buildnumber file="build.version"/>
        <tstamp>
            <format property="timestamp" pattern="yyyy-MM-dd HH:mm:ss"/>
        </tstamp>
            <jar destfile="${dist.jar}" update="true">
     
        <manifest>
            <attribute name="Manifest-Version" value="1.0" />        
            <attribute name="Version" value="1.0.1" />
            <attribute name="Created-By" value="Me" />        
            <attribute name="Bundle" value="${build.number}"/>
            <attribute name="Bundle-Date" value="${timestamp}" />
        </manifest>
        </jar>
 </target>

Java code for Java Application 

  public static  String getVersionBuildNumberAndDateFromJar(){
        String buildNumber="";
        try {
            InputStream stream = (new EscrowPaymentsAppClient()).getClass().getResourceAsStream("/META-INF/MANIFEST.MF");
            Manifest manifest = new Manifest(stream);
            Attributes attributes = manifest.getMainAttributes();
            String version = attributes.getValue("Version");
            String bundle = attributes.getValue("Bundle");
            String bundle_date = attributes.getValue("Bundle-Date");
            stream.close();
            if (bundle!=null && !"null".equals(bundle))
                buildNumber = " [version:"+ version + ", bundle:"+ bundle + ", date:" + bundle_date+"] ";

        } catch (Exception e) {
            e.printStackTrace();
        }
        return buildNumber;
    }