#vulnerable code 
                             private void init() throws IOException {
		try {
			perfData = PerfData.connect(Integer.parseInt(pid));
			perfDataSupport = true;
		} catch (Exception e) {
			System.err.println("PerfData not support");
		}

		vmArgs = Utils.join(jmxClient.getRuntimeMXBean().getInputArguments(), " ");

		Map<String, String> systemProperties_ = jmxClient.getRuntimeMXBean().getSystemProperties();
		osUser = systemProperties_.get("user.name");
		jvmVersion = systemProperties_.get("java.version");
		jvmMajorVersion = getJavaMajorVersion();

		permGenName = jmxClient.getMemoryPoolManager().getPermMemoryPool().getName().toLowerCase();

		threadCpuTimeSupported = jmxClient.getThreadMXBean().isThreadCpuTimeSupported();
		threadMemoryAllocatedSupported = jmxClient.getThreadMXBean().isThreadAllocatedMemorySupported();

		processors = jmxClient.getOperatingSystemMXBean().getAvailableProcessors();
		isLinux = jmxClient.getOperatingSystemMXBean().getName().toLowerCase(Locale.US).contains("linux");
	} 
                            #location 16 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             private void init() throws IOException {
		try {
			perfData = PerfData.connect(Integer.parseInt(pid));
			perfDataSupport = true;
		} catch (Exception e) {
			System.err.println("PerfData not support");
		}

		if (perfDataSupport) {
			vmArgs = (String) perfData.findCounter("java.rt.vmArgs").getValue();
		} else {
			vmArgs = Utils.join(jmxClient.getRuntimeMXBean().getInputArguments(), " ");
		}

		Map<String, String> systemProperties_ = jmxClient.getRuntimeMXBean().getSystemProperties();
		osUser = systemProperties_.get("user.name");
		jvmVersion = systemProperties_.get("java.version");
		jvmMajorVersion = getJavaMajorVersion();

		permGenName = jvmMajorVersion >= 8 ? "metaspace" : "perm";

		threadCpuTimeSupported = jmxClient.getThreadMXBean().isThreadCpuTimeSupported();
		threadMemoryAllocatedSupported = jmxClient.getThreadMXBean().isThreadAllocatedMemorySupported();

		processors = jmxClient.getOperatingSystemMXBean().getAvailableProcessors();
		isLinux = jmxClient.getOperatingSystemMXBean().getName().toLowerCase(Locale.US).contains("linux");
	}