Socket編程(1)-InetAddress

一.InetAddress實例獲取
 1) InetAddress.getByName(String str) : 用主機名/Ip地址獲取Inetaddress對象
 2) InetAddress.getByAddress(String hostname,byte[] b) : 用比特數組地址建立InetAddress, 該方法不用與dns交互,直接建立對象,適合新建dns上不存在的主機地址
 3) InetAddress.getLocalHost(); 返回本機在dns上的主機名和地址
 4) InetAddress[]  -->  InetAddress.getAllByName(String str) : 獲取dns上主機名映射的所有地址
 二. 實例方法
  1) getHostName() : 返回InetAddress中的主機名
  2) toString() : 返字符串"主機名/ip地址"
  3) getHostAddress() : 返回初始化InetAddress時的str
  4) getCanonicalHostName() : 不從緩存中找hostAddress,重新連接DNS查找 : 61.135.169.125
 三. NetworkInterface
 1) 靜態方法:
        NetworkInterface.getByName(String str) : 根據接口名,返回接口實例
NetworkInterface.getNetworkInterfaces() : 返回本機所有網絡接口
 2) 實例方法
        getInetAddresses() : 返回此網絡接口的InetAddress枚舉(多個實例)
        getName() : 返回網絡接口的名字  (net27)
        getDisplayName() : 更友好的返回網絡接口的名字  (Dell 無線 1397 WLAN Mini-Card-Native WiFi Filter Driver-0000)

public static void main(String[] args) {
	try {
		InetAddress add = InetAddress.getByName("www.baidu.com");	//當主機禁止主機名nds查找時,該方法報異常,可選擇getByAddress
		System.out.println(add.getHostName());		//www.baidu.com
		System.out.println(add.getHostAddress());	//61.135.169.125
		System.out.println(add.getCanonicalHostName());//不從緩存中找hostAddress,重新連接DNS查找 : 61.135.169.125
		byte[] b = add.getAddress();		//getAddress()獲取字節數組
		System.out.println(b.length);		//4,可用於判斷地址是ipv4還是ipv6(16字節地址)

		InetAddress add2 = InetAddress.getByName("61.135.169.125");
		System.out.println(add2.getHostName());		//61.135.169.125,返回初始化時的str
		System.out.println(add2.getHostAddress());	//61.135.169.125
		
		byte[] b1 = {107,23,(byte)216,(byte) 253};
		InetAddress add3 = InetAddress.getByAddress("myComputer",b1);//該方法不用與dns交互,直接建立對象,適合新建dns上不存在的主機地址
		System.out.println(add3);		//myComputer/107.23.216.253
		
		InetAddress[] addrs = InetAddress.getAllByName("www.baidu.com");
		for(InetAddress addr:addrs){  
			System.out.println(addr);	
			// www.baidu.com/61.135.169.121 
			// www.baidu.com/61.135.169.125
		}
		
		InetAddress localhostOnDNS = InetAddress.getLocalHost();	//返回本機在dns上的主機名和地址
		System.out.println(localhostOnDNS);		//PC201403091545/192.168.1.18
		
		Enumeration<NetworkInterface> e = NetworkInterface.getNetworkInterfaces(); //返回本機所有網絡接口
		while(e.hasMoreElements()){
			NetworkInterface ni = e.nextElement();
			System.out.println(ni.getDisplayName());
			System.out.println(ni.getName());
		}
		/*  Dell 無線 1397 WLAN Mini-Card-Native WiFi Filter Driver-0000
			net27
			Dell 無線 1397 WLAN Mini-Card-WFP LightWeight Filter-0000
			net28
			Microsoft Virtual WiFi Miniport Adapter #9-Native WiFi Filter Driver-0000
			net29
			Microsoft Virtual WiFi Miniport Adapter #9-Liebao Wifi NAT Driver-0000
			net30
		 */
		
	} catch (UnknownHostException e) {
		System.out.println("目標不可達");
	}catch (SocketException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
}