java 获取局域网中的所有主机名和IP地址

DOS命令

java exec

执行外部命令

String command = "net view"
Runtime r = Runtime.getRuntime();
Process p = r.exec(command);
BufferedReader br = new BufferedReader(new InputStreamReader(p
                    .getInputStream()));

提取局域网IP

public static List<String>  getIPs()
    {
        List<String> list = new ArrayList<String>();
        boolean flag = false;
        int count=0;
        Runtime r = Runtime.getRuntime();
        Process p;
        try {
            p = r.exec("arp -a");
            BufferedReader br = new BufferedReader(new InputStreamReader(p
                    .getInputStream()));
            String inline;
            while ((inline = br.readLine()) != null) {
                if(inline.indexOf("接口") > -1){
                    flag = !flag;
                    if(!flag){
                        //碰到下一个"接口"退出循环
                        break;
                    }
                }
                if(flag){
                    count++;
                    if(count > 2){
                        //有效IP
                        String[] str=inline.split(" {4}");
                        list.add(str[0]);
                    }
                }
                System.out.println(inline);
            }
            br.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println(list);
        return list;
    }

根据IP提取主机名

public static Map<String,String> getHostnames(List<String> ips){

        Map<String,String> map = new HashMap<String,String>();
        System.out.println("正在提取hostname...");
        for(String ip : ips){
            String command = "ping -a " + ip;
            Runtime r = Runtime.getRuntime();
            Process p;
            try {
                p = r.exec(command);
                BufferedReader br = new BufferedReader(new InputStreamReader(p
                        .getInputStream()));
                String inline;
                while ((inline = br.readLine()) != null) {
                    if(inline.indexOf("[") > -1){
                        int start = inline.indexOf("Ping ");
                        int end = inline.indexOf("[");
                        String hostname = inline.substring(start+"Ping ".length(),end-1);
                        System.out.println(hostname);
                        map.put(ip,hostname);
                    }
                }
                br.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        System.out.println("提取结束！");
        return map;
    }

结果

{  222.26.28.51=BY-201507012043,   224.0.0.2=all-routers.mcast.net,   222.26.28.20=xxx-PC,   224.0.0.22=igmp.mcast.net,   222.26.28.218=xxx-PC,   222.26.28.223=xxx-PC}