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Debug 笔记 <如何从Java枚举所有已启用的NIC卡的IP地址？>
提问
缺少解析输出ipconfig，没有人有100％的纯Java方式做到这一点吗？
回答一
这很简单：
try {
InetAddress localhost = InetAddress.getLocalHost();
LOG.info(" IP Addr: " + localhost.getHostAddress());
// Just in case this host has multiple IP addresses....
InetAddress[] allMyIps = InetAddress.getAllByName(localhost.getCanonicalHostName());
if (allMyIps != null && allMyIps.length > 1) {
LOG.info(" Full list of IP addresses:");
for (int i = 0; i < allMyIps.length; i++) {
LOG.info(" " + allMyIps[i]);
}
}
} catch (UnknownHostException e) {
LOG.info(" (error retrieving server host name)");
}
try {
LOG.info("Full list of Network Interfaces:");
for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {
NetworkInterface intf = en.nextElement();
LOG.info(" " + intf.getName() + " " + intf.getDisplayName());
for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements(); ) {
LOG.info(" " + enumIpAddr.nextElement().toString());
}
}
} catch (SocketException e) {
LOG.info(" (error retrieving network interface list)");
}
回答二
其中一些仅在JDK 1.6及更高版本中有效（该发行版中添加了一种方法。）
List<InetAddress> addrList = new ArrayList<InetAddress>();
for(Enumeration<NetworkInterface> eni = NetworkInterface.getNetworkInterfaces(); eni.hasMoreElements(); ) {
final NetworkInterface ifc = eni.nextElement();
if(ifc.isUp()) {
for(Enumeration<InetAddress> ena = ifc.getInetAddresses(); ena.hasMoreElements(); ) {
addrList.add(ena.nextElement());
}
}
}
在1.6之前的版本要困难一些-在此之前不支持isUp（）。
回答三
由于添加了InterfaceAddress代码，因此该代码仅在Java 1.6中有效。
try
{
System.out.println("Output of Network Interrogation:");
System.out.println("********************************\n");
InetAddress theLocalhost = InetAddress.getLocalHost();
System.out.println(" LOCALHOST INFO");
if(theLocalhost != null)
{
System.out.println(" host: " + theLocalhost.getHostName());
System.out.println(" class: " + theLocalhost.getClass().getSimpleName());
System.out.println(" ip: " + theLocalhost.getHostAddress());
System.out.println(" chost: " + theLocalhost.getCanonicalHostName());
System.out.println(" byteaddr: " + toMACAddrString(theLocalhost.getAddress()));
System.out.println(" sitelocal?: " + theLocalhost.isSiteLocalAddress());
System.out.println("");
}
else
{
System.out.println(" localhost was null");
}
Enumeration<NetworkInterface> theIntfList = NetworkInterface.getNetworkInterfaces();
List<InterfaceAddress> theAddrList = null;
NetworkInterface theIntf = null;
InetAddress theAddr = null;
while(theIntfList.hasMoreElements())
{
theIntf = theIntfList.nextElement();
System.out.println("--------------------");
System.out.println(" " + theIntf.getDisplayName());
System.out.println(" name: " + theIntf.getName());
System.out.println(" mac: " + toMACAddrString(theIntf.getHardwareAddress()));
System.out.println(" mtu: " + theIntf.getMTU());
System.out.println(" mcast?: " + theIntf.supportsMulticast());
System.out.println(" loopback?: " + theIntf.isLoopback());
System.out.println(" ptp?: " + theIntf.isPointToPoint());
System.out.println(" virtual?: " + theIntf.isVirtual());
System.out.println(" up?: " + theIntf.isUp());
theAddrList = theIntf.getInterfaceAddresses();
System.out.println(" int addrs: " + theAddrList.size() + " total.");
int addrindex = 0;
for(InterfaceAddress intAddr : theAddrList)
{
addrindex++;
theAddr = intAddr.getAddress();
System.out.println(" " + addrindex + ").");
System.out.println(" host: " + theAddr.getHostName());
System.out.println(" class: " + theAddr.getClass().getSimpleName());
System.out.println(" ip: " + theAddr.getHostAddress() + "/" + intAddr.getNetworkPrefixLength());
System.out.println(" bcast: " + intAddr.getBroadcast().getHostAddress());
int maskInt = Integer.MIN_VALUE >> (intAddr.getNetworkPrefixLength()-1);
System.out.println(" mask: " + toIPAddrString(maskInt));
System.out.println(" chost: " + theAddr.getCanonicalHostName());
System.out.println(" byteaddr: " + toMACAddrString(theAddr.getAddress()));
System.out.println(" sitelocal?: " + theAddr.isSiteLocalAddress());
System.out.println("");
}
}
}
catch (SocketException e)
{
e.printStackTrace();
}
catch (UnknownHostException e)
{
e.printStackTrace();
}
“ toMACAddrString”方法如下所示：
public static String toMACAddrString(byte[] a)
{
if (a == null)
{
return "null";
}
int iMax = a.length - 1;
if (iMax == -1)
{
return "[]";
}
StringBuilder b = new StringBuilder();
b.append('[');
for (int i = 0;; i++)
{
b.append(String.format("%1$02x", a[i]));
if (i == iMax)
{
return b.append(']').toString();
}
b.append(":");
}
}
和“ toIPAddrString”方法在这里：
public static String toIPAddrString(int ipa)
{
StringBuilder b = new StringBuilder();
b.append(Integer.toString(0x000000ff & (ipa >> 24)));
b.append(".");
b.append(Integer.toString(0x000000ff & (ipa >> 16)));
b.append(".");
b.append(Integer.toString(0x000000ff & (ipa >> 8)));
b.append(".");
b.append(Integer.toString(0x000000ff & (ipa)));
return b.toString();
}
在上面的try / catch中，我在名为IPConfig的类中的方法dump（）中拥有第一组代码。
然后，我只是在IPConfig中放置了一个main方法来调用新的IPConfig（），dump（），这样当我试图找出一些古怪的网络问题时，我可以看到Java认为这种情况还在继续。
我发现我的Fedora框报告的信息不同于Windows的LocalHost信息，这导致我的Java程序出现了一些问题。
我意识到它与其他答案类似，但是它几乎可以打印出您可以从接口和ipaddress api上获得的所有有趣信息。
回答四
更新以修复Jared对于JDK 1.7的答案。
// Get list of IP addresses from all local network interfaces. (JDK1.7)
// -----------------------------------------------------------
public List<InetAddress> getListOfIPsFromNIs(){
List<InetAddress> addrList = new ArrayList<InetAddress>();
Enumeration<NetworkInterface> enumNI = NetworkInterface.getNetworkInterfaces();
while ( enumNI.hasMoreElements() ){
NetworkInterface ifc = enumNI.nextElement();
if( ifc.isUp() ){
Enumeration<InetAddress> enumAdds = ifc.getInetAddresses();
while ( enumAdds.hasMoreElements() ){
InetAddress addr = enumAdds.nextElement();
addrList.add(addr);
System.out.println(addr.getHostAddress()); //<---print IP
}
}
}
return addrList;
}
正如Sam Skuce强调的那样：
这不会在JDK 1.7中编译。getNetworkInterfaces返回一个未实现Iterable的枚举。–山姆·斯库斯（Sam Skuce）2012年7月11日19:58
输出
fe80:0:0:0:800:aaaa:aaaa:0%8
192.168.56.1
fe80:0:0:0:227:aaa:aaaa:6b5%2
123.123.123.123
0:0:0:0:0:0:0:1%1
127.0.0.1
文章翻译自Stack Overflow :stackoverflow.com/questions/4…
