get complete absolute url to a build run

gistfile1.java

    /**
     * returns the complete url to a build run
     * e.g. http://localhost:8080/job/test/5/
     * @param build
     * @return build run url as String
     */
    private String getAbsoluteBuildUrl(AbstractBuild build) {
    	
    	return getBaseUrl() + build.getUrl();
    }
    
    /**
     * returns the value that is configured in
     * Manage Jenkins -> Configure System -> Jenkins URL
     * e.g. http://localhost:8080/
     * After new installation this value has to be changed once
     * to have an effect. 
     * @return base url as String
     */
    private String getBaseUrl() {
        final String rootUrl = Jenkins.getInstance().getRootUrl();

        if (StringUtils.isNotEmpty(rootUrl)) {
            return rootUrl;
        }

        return Jenkins.getInstance().getRootUrlFromRequest();
    }