#vulnerable code 
                                private Artifact chooseBinaryBits() throws MojoExecutionException {
        String plat;
        String os = System.getProperty("os.name");
        getLog().debug("OS = " + os);

        // See here for possible values of os.name:
        // http://lopica.sourceforge.net/os.html
        if (os.startsWith("Windows")) {
            plat = "win32";
        } else if ("Linux".equals(os)) {
            plat = "linux";
        } else if ("Solaris".equals(os) || "SunOS".equals(os)) {
            plat = "solaris";
        } else if ("Mac OS X".equals(os) || "Darwin".equals(os)) {
            plat = (isBelow10_8(System.getProperty("os.version"))) ? "mac" : "osx";
        } else {
            throw new MojoExecutionException("Sorry, Launch4j doesn't support the '" + os + "' OS.");
        }

        return factory.createArtifactWithClassifier(LAUNCH4J_GROUP_ID, LAUNCH4J_ARTIFACT_ID,
                getLaunch4jVersion(), "jar", "workdir-" + plat);
    } 
                            #location 15 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                private Artifact chooseBinaryBits() throws MojoExecutionException {
        String plat;
        String os = System.getProperty("os.name");
        getLog().debug("OS = " + os);

        // See here for possible values of os.name:
        // http://lopica.sourceforge.net/os.html
        if (os.startsWith("Windows")) {
            plat = "win32";
        } else if ("Linux".equals(os)) {
            plat = "linux";
        } else if ("Solaris".equals(os) || "SunOS".equals(os)) {
            plat = "solaris";
        } else if ("Mac OS X".equals(os) || "Darwin".equals(os)) {
            plat = isBelowMacOSX_10_8() ? "mac" : "osx";
        } else {
            throw new MojoExecutionException("Sorry, Launch4j doesn't support the '" + os + "' OS.");
        }

        return factory.createArtifactWithClassifier(LAUNCH4J_GROUP_ID, LAUNCH4J_ARTIFACT_ID,
                getLaunch4jVersion(), "jar", "workdir-" + plat);
    }