java如何测试网络连通性

本文实例为大家分享了Java测试网络连通性的方法，供大家参考，具体内容如下

第一种方式：利用java运行时：
Java代码

/**
* test network
* @param ip
*/
private void getNetworkState(String ip) {
 Runtime runtime = Runtime.getRuntime();
 try {
   log.info("=================正在测试网络连通性ip："+ip);
   Process process = runtime.exec("ping " +ip);
   InputStream iStream = process.getInputStream();
   InputStreamReader iSReader = new InputStreamReader(iStream,"UTF-8");
   BufferedReader bReader = new BufferedReader(iSReader);
   String line = null;
   StringBuffer sb = new StringBuffer();
   while ((line = bReader.readLine()) != null) {
     sb.append(line);
   }
   iStream.close();
   iSReader.close();
   bReader.close();
   String result = new String(sb.toString().getBytes("UTF-8"));
   log.info("ping result:"+result);
   if (!StringUtils.isBlank(result)) {
     if (result.indexOf("TTL") > 0 || result.indexOf("ttl") > 0) {
       log.info("网络正常，时间: " + TimeUtil.getCurDate("yyyy-mm-dd hh:mm:ss"));    
     } else {
       log.info("网络断开，时间 :" + TimeUtil.getCurDate("yyyy-mm-dd hh:mm:ss"));

}
   }
 } catch (Exception e) {
   log.error("网络异常："+e.getMessage());
   e.printStackTrace();
 }
}

在windows平台上，上面代码没有为，ping ip 会结束，而在linux环境中ping命令，ping不通时，
会卡住，ping通，会不定的输出信息，考虑用另一种方式socket。

第二种方式socket：
Java代码

package com.util.network;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.NetworkInterface;
import java.net.Socket;
import java.net.SocketAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Enumeration;

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
* 测试网络连通性
*
* @author donald
*
*/
public class NetworkHelper {
 private static Logger log = LoggerFactory.getLogger(NetworkHelper.class);
 private static NetworkHelper instance = null;
 public static synchronized NetworkHelper getInstance(){
   if(instance == null){
     instance = new NetworkHelper();
   }
   return instance;

}

/**
  * 测试本地能否ping ip
  *
  * @param ip
  * @return
  */
 public boolean isReachIp(String ip) {
   boolean isReach = false;
   try {
     InetAddress address = InetAddress.getByName(ip);// ping this IP

if (address instanceof java.net.Inet4Address) {
       log.info(ip + " is ipv4 address");
     } else if (address instanceof java.net.Inet6Address) {
       log.info(ip + " is ipv6 address");
     } else {
       log.info(ip + " is unrecongized");
     }
     if (address.isReachable(5000)) {
       isReach = true;
       log.info("SUCCESS - ping " + ip
           + " with no interface specified");
     } else {
       isReach = false;
       log.info("FAILURE - ping " + ip
           + " with no interface specified");
     }
   } catch (Exception e) {
     log.error("error occurs:" + e.getMessage());
   }
   return isReach;
 }

/**
  * 测试本地所有的网卡地址都能ping通 ip
  *
  * @param ip
  * @return
  */
 public boolean isReachNetworkInterfaces(String ip) {
   boolean isReach = false;
   try {
     InetAddress address = InetAddress.getByName(ip);// ping this IP

if (address instanceof java.net.Inet4Address) {
       log.info(ip + " is ipv4 address");
     } else if (address instanceof java.net.Inet6Address) {
       log.info(ip + " is ipv6 address");
     } else {
       log.info(ip + " is unrecongized");
     }
     if (address.isReachable(5000)) {
       isReach = true;
       log.info("SUCCESS - ping " + ip
           + " with no interface specified");
     } else {
       isReach = false;
       log.info("FAILURE - ping " + ip
           + " with no interface specified");
     }
     if (isReach) {
       log.info("-------Trying different interfaces--------");
       Enumeration<NetworkInterface> netInterfaces = NetworkInterface
           .getNetworkInterfaces();
       while (netInterfaces.hasMoreElements()) {
         NetworkInterface ni = netInterfaces.nextElement();
         log.info("Checking interface, DisplayName:"
             + ni.getDisplayName() + ", Name:" + ni.getName());
         if (address.isReachable(ni, 0, 5000)) {
           isReach = true;
           log.info("SUCCESS - ping " + ip);
         } else {
           isReach = false;
           log.info("FAILURE - ping " + ip);
         }
         Enumeration<InetAddress> ips = ni.getInetAddresses();
         while (ips.hasMoreElements()) {
           log.info("IP: " + ips.nextElement().getHostAddress());
         }
         log.info("-----------------check now NetworkInterface is done--------------------------");
       }
     }
   } catch (Exception e) {
     log.error("error occurs:" + e.getMessage());
   }
   return isReach;
 }

/**
  * 获取能与远程主机指定端口建立连接的本机ip地址
  * @param remoteAddr
  * @param port
  * @return
  */
 public String getReachableIP(InetAddress remoteAddr, int port) {
   String retIP = null;
   Enumeration<NetworkInterface> netInterfaces;
   try {
     netInterfaces = NetworkInterface.getNetworkInterfaces();
     while (netInterfaces.hasMoreElements()) {
       NetworkInterface ni = netInterfaces.nextElement();
       Enumeration<InetAddress> localAddrs = ni.getInetAddresses();
       while (localAddrs.hasMoreElements()) {
         InetAddress localAddr = localAddrs.nextElement();
         if (isReachable(localAddr, remoteAddr, port, 5000)) {
           retIP = localAddr.getHostAddress();
           break;
         }
       }
     }
   } catch (SocketException e) {
     log.error("Error occurred while listing all the local network addresses:"
         + e.getMessage());
   }
   if (retIP == null) {
     log.info("NULL reachable local IP is found!");
   } else {
     log.info("Reachable local IP is found, it is " + retIP);
   }
   return retIP;
 }
 /**
  * 获取能与远程主机指定端口建立连接的本机ip地址
  * @param remoteIp
  * @param port
  * @return
  */
 public String getReachableIP(String remoteIp, int port) {

String retIP = null;
   InetAddress remoteAddr = null;
   Enumeration<NetworkInterface> netInterfaces;
   try {
     remoteAddr = InetAddress.getByName(remoteIp);
     netInterfaces = NetworkInterface.getNetworkInterfaces();
     while (netInterfaces.hasMoreElements()) {
       NetworkInterface ni = netInterfaces.nextElement();
       Enumeration<InetAddress> localAddrs = ni.getInetAddresses();
       while (localAddrs.hasMoreElements()) {
         InetAddress localAddr = localAddrs.nextElement();
         if (isReachable(localAddr, remoteAddr, port, 5000)) {
           retIP = localAddr.getHostAddress();
           break;
         }
       }
     }
   } catch (UnknownHostException e) {
     log.error("Error occurred while listing all the local network addresses:"+ e.getMessage());
   }catch (SocketException e) {
     log.error("Error occurred while listing all the local network addresses:"+ e.getMessage());
   }
   if (retIP == null) {
     log.info("NULL reachable local IP is found!");
   } else {
     log.info("Reachable local IP is found, it is " + retIP);
   }
   return retIP;
 }
 /**
  * 测试localInetAddr能否与远程的主机指定端口建立连接相连
  *
  * @param localInetAddr
  * @param remoteInetAddr
  * @param port
  * @param timeout
  * @return
  */
 public boolean isReachable(InetAddress localInetAddr,
     InetAddress remoteInetAddr, int port, int timeout) {
   boolean isReachable = false;
   Socket socket = null;
   try {
     socket = new Socket();
     // 端口号设置为 0 表示在本地挑选一个可用端口进行连接
     SocketAddress localSocketAddr = new InetSocketAddress(
         localInetAddr, 0);
     socket.bind(localSocketAddr);
     InetSocketAddress endpointSocketAddr = new InetSocketAddress(
         remoteInetAddr, port);
     socket.connect(endpointSocketAddr, timeout);
     log.info("SUCCESS - connection established! Local: "
         + localInetAddr.getHostAddress() + " remote: "
         + remoteInetAddr.getHostAddress() + " port" + port);
     isReachable = true;
   } catch (IOException e) {
     log.error("FAILRE - CAN not connect! Local: "
         + localInetAddr.getHostAddress() + " remote: "
         + remoteInetAddr.getHostAddress() + " port" + port);
   } finally {
     if (socket != null) {
       try {
         socket.close();
       } catch (IOException e) {
         log.error("Error occurred while closing socket:"
             + e.getMessage());
       }
     }
   }
   return isReachable;
 }

/**
  * 测试localIp能否与远程的主机指定端口建立连接相连
  *
  * @param localIp
  * @param remoteIp
  * @param port
  * @param timeout
  * @return
  */
 public boolean isReachable(String localIp, String remoteIp,
     int port, int timeout) {
   boolean isReachable = false;
   Socket socket = null;
   InetAddress localInetAddr = null;
   InetAddress remoteInetAddr = null;
   try {
     localInetAddr = InetAddress.getByName(localIp);
     remoteInetAddr = InetAddress.getByName(remoteIp);
     socket = new Socket();
     // 端口号设置为 0 表示在本地挑选一个可用端口进行连接
     SocketAddress localSocketAddr = new InetSocketAddress(
         localInetAddr, 0);
     socket.bind(localSocketAddr);
     InetSocketAddress endpointSocketAddr = new InetSocketAddress(
         remoteInetAddr, port);
     socket.connect(endpointSocketAddr, timeout);
     log.info("SUCCESS - connection established! Local: "
         + localInetAddr.getHostAddress() + " remote: "
         + remoteInetAddr.getHostAddress() + " port" + port);
     isReachable = true;
   } catch (IOException e) {
     log.error("FAILRE - CAN not connect! Local: "
         + localInetAddr.getHostAddress() + " remote: "
         + remoteInetAddr.getHostAddress() + " port" + port);
   } finally {
     if (socket != null) {
       try {
         socket.close();
       } catch (IOException e) {
         log.error("Error occurred while closing socket:"
             + e.getMessage());
       }
     }
   }
   return isReachable;
 }

public static void main(String[] args) {
    if(NetworkHelper.getInstance().isReachIp("192.168.126.128")){
      log.info("=======本机可以ping通ip："+"192.168.126.128");
    }
    else{
      log.info("=======本机ping不通ip："+"192.168.126.128");
    }
    if(NetworkHelper.getInstance().isReachNetworkInterfaces("192.168.126.128")){
      log.info("=======本机所有网卡可以ping通ip："+"192.168.126.128");
    }
    else{
      log.info("=======本机所有网卡ping不通ip："+"192.168.126.128");
    }
    String localIp = NetworkHelper.getInstance().getReachableIP("192.168.126.128",8081);
    if(!StringUtils.isBlank(localIp)){
      log.info("=======本机可以与ip："+"192.168.126.128"+",port:"+8081+"建立连接的IP："+localIp);
    }
    else{
      log.info("=======本机不能与ip："+"192.168.126.128"+",port:"+8081+"建立连接的IP");
    }
 }

}