模拟dns优选，处理dns的响应时间
说明
主要用于选择更合适的dns解析服务器。可以自定义配置需要测试的dns地址。 如果你们的宽带是电信联通或移动可以去查询它们所在城市的dns地址也可以加入测试
配置文件 dnstest.ini
#要进行解析的域名
test www.baidu.com
test www.oschina.com
test tv.sohu.com
#可用的dns。
dns 8.8.8.8
dns 8.8.4.4
dns 114.114.114.114
dns 114.114.115.115
dns 223.5.5.5
dns 223.6.6.6
dns 1.2.4.8
dns 210.2.4.8
dns 208.67.222.222
dns 208.67.220.220
dns 101.226.4.6
dns 123.125.82.6
dns 123.125.83.6
代码
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
public class DNSSpeed implements Runnable {
private final InetAddress dns;
private final String dd;
public DNSSpeed(String dns, String dd) throws UnknownHostException {
this.dns = InetAddress.getByName(dns);
this.dd = dd;
}
public void run() {
byte[] data = toDnsBytes(dd);
DatagramSocket dispatcher = null;
DatagramPacket pack = null;
boolean isSuccess = false;
long start = System.currentTimeMillis();
try {
pack = new DatagramPacket(data, data.length, dns, 53);
dispatcher = createDatagramSocket();
dispatcher.setSoTimeout(1000);
dispatcher.send(pack);
data = new byte[512];
pack = new DatagramPacket(data, data.length);
dispatcher.receive(pack);
if (pack.getLength() > 12) {//简单验证返回包
isSuccess = true;
}
} catch (Exception e) {
} finally {
if (null != dispatcher) {
dispatcher.close();
}
String info = "%-15s\t%-20s\t%s\t%4d\t";
info = String.format(info, dns.getHostAddress(), dd, isSuccess, (System.currentTimeMillis() - start));
System.out.println(info);
}
}
/**
* 组dns查询包
* 2015年7月14日
* @param dd
* @return
*/
protected static final byte[] toDnsBytes(String dd) {
ByteBuffer b = ByteBuffer.allocateDirect(512);
short id = (short) (3 + r.nextInt(1000));
b.putShort(id);// id;
b.put((byte) 0x01);
b.put((byte) 0x00);
b.putShort((short) (0x01 & 0xFFFF));
b.putShort((short) (0x00 & 0xFFFF));
b.putShort((short) (0x00 & 0xFFFF));
b.putShort((short) (0x00 & 0xFFFF));
String[] ss = dd.split("\\.");
for (int i = 0; i < ss.length; i++) {
byte[] bb = ss[i].getBytes();
b.put((byte) (bb.length & 0xFF));
b.put(bb);
}
b.put((byte) 0x00);
b.putShort((short) 0x01);
b.putShort((short) 0x01);
b.flip();
byte[] bb = new byte[b.remaining()];
b.get(bb);
return bb;
}
private static Random r = new Random();
/**
* 随机取一个 50000开始的端口
* 2015年7月14日
* @return
*/
private static synchronized DatagramSocket createDatagramSocket() {
DatagramSocket result = null;
while (null == result) {
try {
int port = 50000 + r.nextInt(10000);
result = new DatagramSocket(port);
} catch (SocketException e) {
result = null;
} finally {
}
}
return result;
}
public static void main(String[] args) throws UnknownHostException {
List<String> config = loadFile("dnstest.ini");
List<String> dns = getConfig(config, "dns");
List<String> test = getConfig(config, "test");
for (String s : dns) {
for (String t : test) {
new DNSSpeed(s, t).run();
}
}
}
/**
* 取key. 配置以 key value格式
* 2015年7月14日
* @param config
* @param key
* @return
*/
protected static final List<String> getConfig(List<String> config, String key) {
List<String> result = new ArrayList<String>();
for (String ss : config) {
ss = ss.trim();
if (ss.startsWith(key)) {
result.add(ss.substring(key.length()).trim());
}
}
return result;
}
/**
* 加载配置文件转list
* 2015年7月14日
* @param path
* @return
*/
protected static final List<String> loadFile(String path) {
List<String> result = new ArrayList<String>();
BufferedReader in = null;
try {
in = new BufferedReader(new FileReader(path));
String s = null;
while (null != (s = in.readLine())) {
s = s.trim();
if (!s.startsWith("#") && !s.isEmpty()) {//过滤掉空行及#号开头的配置
result.add(s);
}
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (null != in) {
try {
in.close();
} catch (IOException e) {
}
}
}
return result;
}
}
执行结果
8.8.8.8 www.baidu.com true 12
8.8.8.8 www.oschina.com true 4
8.8.8.8 tv.sohu.com true 7
8.8.4.4 www.baidu.com true 7
8.8.4.4 www.oschina.com true 8
8.8.4.4 tv.sohu.com true 6
114.114.114.114 www.baidu.com true 5
114.114.114.114 www.oschina.com true 6
114.114.114.114 tv.sohu.com true 8
114.114.115.115 www.baidu.com true 5
114.114.115.115 www.oschina.com true 6
114.114.115.115 tv.sohu.com true 5
223.5.5.5 www.baidu.com true 41
223.5.5.5 www.oschina.com true 44
223.5.5.5 tv.sohu.com true 42
223.6.6.6 www.baidu.com true 40
223.6.6.6 www.oschina.com true 45
223.6.6.6 tv.sohu.com true 46
1.2.4.8 www.baidu.com true 8
1.2.4.8 www.oschina.com true 6
1.2.4.8 tv.sohu.com true 13
210.2.4.8 www.baidu.com true 6
210.2.4.8 www.oschina.com true 8
210.2.4.8 tv.sohu.com true 187
208.67.222.222 www.baidu.com true 5
208.67.222.222 www.oschina.com true 6
208.67.222.222 tv.sohu.com true 4
208.67.220.220 www.baidu.com true 5
208.67.220.220 www.oschina.com true 7
208.67.220.220 tv.sohu.com true 10
101.226.4.6 www.baidu.com true 5
101.226.4.6 www.oschina.com true 5
101.226.4.6 tv.sohu.com true 6
123.125.82.6 www.baidu.com true 5
123.125.82.6 www.oschina.com true 7
123.125.82.6 tv.sohu.com true 5
123.125.83.6 www.baidu.com true 5
123.125.83.6 www.oschina.com true 5
123.125.83.6 tv.sohu.com true 6