如何检测域名IP是否解析到当前服务器上

Question

如何检测域名IP是否解析到当前服务器上，检测域名IP 是否指向本机liunx 服务器的公网IP，或者能检测到指向当前服务器也行，注意，我问的是用JAVA怎么实现

Answer 1

方法一：

public boolean pingIp(String ip) throws UnknownHostException, IOException{
        //能ping通放回true 反之 false 超时时间 3000毫秒
        return InetAddress.getByName(ip).isReachable(3000);
    }

方法二：

public static void ping02(String ipAddress) throws Exception {
        String line = null;
        try {
            Process pro = Runtime.getRuntime().exec("ping " + ipAddress);
            BufferedReader buf = new BufferedReader(new InputStreamReader(
                    pro.getInputStream()));
            while ((line = buf.readLine()) != null)
                System.out.println(line);
                getCheckResult(line);//判断方法
        } catch (Exception ex) {
            System.out.println(ex.getMessage());
        }
    }

方法三：

  public static boolean ping(String ipAddress, int pingTimes, int timeOut) {  
        BufferedReader in = null;  
        Runtime r = Runtime.getRuntime();  // 将要执行的ping命令,此命令是windows格式的命令  
        String pingCommand = "ping " + ipAddress + " -n " + pingTimes    + " -w " + timeOut;  
        try {   // 执行命令并获取输出  
            System.out.println(pingCommand);   
            Process p = r.exec(pingCommand);   
            if (p == null) {    
                return false;   
            }
            in = new BufferedReader(new InputStreamReader(p.getInputStream()));   // 逐行检查输出,计算类似出现=23ms TTL=62字样的次数  
            int connectedCount = 0;   
            String line = null;   
            while ((line = in.readLine()) != null) {    
                connectedCount += getCheckResult(line);   
            }   // 如果出现类似=23ms TTL=62这样的字样,出现的次数=测试次数则返回真  
            return connectedCount == pingTimes;  
        } catch (Exception ex) {   
            ex.printStackTrace();   // 出现异常则返回假  
            return false;  
        } finally {   
            try {    
                in.close();   
            } catch (IOException e) {    
                e.printStackTrace();   
            }  
        }
    }
    //若line含有=18ms TTL=16字样,说明已经ping通,返回1,否則返回0.
    private static int getCheckResult(String line) {  // System.out.println("控制台输出的结果为:"+line);  
        Pattern pattern = Pattern.compile("(\\d+ms)(\\s+)(TTL=\\d+)",    Pattern.CASE_INSENSITIVE);  
        Matcher matcher = pattern.matcher(line);  
        while (matcher.find()) {
            return 1;
        }
        return 0; 
    }