#vulnerable code 
                             private static InetAddress findLocalAddressViaNetworkInterface() {
		// 如果hostname +/etc/hosts 得到的是127.0.0.1, 则首选这块网卡
		String preferNamePrefix = SystemPropertiesUtil.getString("localhost.prefer.nic.prefix",
				"LOCALHOST_PREFER_NIC_PREFIX", "bond0.");
		// 如果hostname +/etc/hosts 得到的是127.0.0.1, 和首选网卡都不符合要求，则按顺序遍历下面的网卡
		String defaultNicList = SystemPropertiesUtil.getString("localhost.default.nic.list", "LOCALHOST_DEFAULT_NIC_LIST",
				"bond0,eth0,em0,br0");

		InetAddress resultAddress = null;
		Map<String, NetworkInterface> candidateInterfaces = MapUtil.newHashMap();

		// 遍历所有网卡，找出所有可用网卡，尝试找出符合prefer前缀的网卡
		try {
			for (Enumeration<NetworkInterface> allInterfaces = NetworkInterface.getNetworkInterfaces(); allInterfaces
					.hasMoreElements();) {
				NetworkInterface nic = allInterfaces.nextElement();
				// 检查网卡可用并支持广播
				try {
					if (!nic.isUp() || !nic.supportsMulticast()) {
						continue;
					}
				} catch (SocketException e) {
					continue;
				}

				// 检查是否符合prefer前缀
				String name = nic.getName();
				if (name.startsWith(preferNamePrefix)) {
					// 检查有否非ipv6 非127.0.0.1的inetaddress
					resultAddress = findAvailableInetAddress(nic);
					if (resultAddress != null) {
						return resultAddress;
					}
				} else {
					// 不是Prefer前缀，先放入可选列表
					candidateInterfaces.put(name, nic);
				}
			}

			for (String nifName : defaultNicList.split(",")) {
				NetworkInterface nic = candidateInterfaces.get(nifName);
				resultAddress = findAvailableInetAddress(nic);
				if (resultAddress != null) {
					return resultAddress;
				}
			}
		} catch (SocketException e) {
			return null;
		}
		return null;

	} 
                            #location 30 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             private static InetAddress findLocalAddressViaNetworkInterface() {
		// 如果hostname +/etc/hosts 得到的是127.0.0.1, 则首选这块网卡
		String preferNamePrefix = SystemPropertiesUtil.getString("localhost.prefer.nic.prefix",
				"LOCALHOST_PREFER_NIC_PREFIX", "bond0.");
		// 如果hostname +/etc/hosts 得到的是127.0.0.1, 和首选网卡都不符合要求，则按顺序遍历下面的网卡
		String defaultNicList = SystemPropertiesUtil.getString("localhost.default.nic.list",
				"LOCALHOST_DEFAULT_NIC_LIST", "bond0,eth0,em0,br0");

		InetAddress resultAddress = null;
		Map<String, NetworkInterface> candidateInterfaces = MapUtil.newHashMap();

		// 遍历所有网卡，找出所有可用网卡，尝试找出符合prefer前缀的网卡
		try {
			for (Enumeration<NetworkInterface> allInterfaces = NetworkInterface.getNetworkInterfaces(); allInterfaces
					.hasMoreElements();) {
				NetworkInterface nic = allInterfaces.nextElement();
				// 检查网卡可用并支持广播
				try {
					if (!nic.isUp() || !nic.supportsMulticast()) {
						continue;
					}
				} catch (SocketException e) {
					continue;
				}

				// 检查是否符合prefer前缀
				String name = nic.getName();
				if (name.startsWith(preferNamePrefix)) {
					// 检查有否非ipv6 非127.0.0.1的inetaddress
					resultAddress = findAvailableInetAddress(nic);
					if (resultAddress != null) {
						return resultAddress;
					}
				} else {
					// 不是Prefer前缀，先放入可选列表
					candidateInterfaces.put(name, nic);
				}
			}

			for (String nifName : defaultNicList.split(",")) {
				NetworkInterface nic = candidateInterfaces.get(nifName);
				if (nic != null) {
					resultAddress = findAvailableInetAddress(nic);
					if (resultAddress != null) {
						return resultAddress;
					}
				}
			}
		} catch (SocketException e) {
			return null;
		}
		return null;

	}