Java 根据网址查询DNS/IP地址

demo

import java.io.IOException;

import java.net.*;

/**

 * 查找IP地址

 */

public class TestFindDNS {

  public static void main(String[] args) throws IOException {

    //

    String href = "http://www.cncounter.com/tools/shorturl.php";

    // 端口号

    int port = parsePort(href);

    // 域名

    String host = parseHost(href);

    // IP 地址

    String address = parseIp(host);

    //

    System.out.println("host=" + host);

    System.out.println("port=" + port);

    System.out.println("address=" + address);

  }

  /**

   * 获取端口号

   *

   * @param href 网址, ftp, http, nntp, ... 等等

   * @return

   * @throws IOException

   */

  public static int parsePort(String href) throws IOException {

    //

    URL url = new URL(href);

    // 端口号; 如果 href 中没有明确指定则为 -1

    int port = url.getPort();

    if (port < 0) {

      // 获取对应协议的默认端口号

      port = url.getDefaultPort();

    }

    return port;

  }

  /**

   * 获取Host部分

   *

   * @param href 网址, ftp, http, nntp, ... 等等

   * @return

   * @throws IOException

   */

  public static String parseHost(String href) throws IOException {

    //

    URL url = new URL(href);

    // 获取 host 部分

    String host = url.getHost();

    return host;

  }

  /**

   * 根据域名(host)解析IP地址

   *

   * @param host 域名

   * @return

   * @throws IOException

   */

  public static String parseIp(String host) throws IOException {

    // 根据域名查找IP地址

    InetAddress.getAllByName(host);

    InetAddress inetAddress = InetAddress.getByName(host);

    // IP 地址

    String address = inetAddress.getHostAddress();

    return address;

  }

}

根据IP获取地址

package test;

import net.sf.json.JSONObject;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class GetAddressByIp {
    public static void main(String[] args) {
        String resout = "";
        try {
            String str = getJsonContent("http://ip.taobao.com/service/getIpInfo.php?ip="+"138.30.25.101");
            System.out.println(str);
            JSONObject obj = JSONObject.fromObject(str);
            JSONObject obj2 =  (JSONObject) obj.get("data");
            String code = obj.get("code").toString();
            if(code.equals("0")) {
                resout =  obj2.get("country")+"--" +obj2.get("area")+"--" +obj2.get("city")+"--" +obj2.get("isp");
            } else {
                resout =  "IP地址有误";
            }
        } catch(Exception e) {

            e.printStackTrace();
            resout = "获取IP地址异常："+e.getMessage();
        }
        System.out.println("result: " + resout);
    }

    public static String getJsonContent(String urlStr) {
        try {
            // 获取HttpURLConnection连接对象
            URL url = new URL(urlStr);
            HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
            // 设置连接属性
            httpConn.setConnectTimeout(3000);
            httpConn.setDoInput(true);
            httpConn.setRequestMethod("GET");
            // 获取相应码
            int respCode = httpConn.getResponseCode();
            if (respCode == 200) {
                return ConvertStream2Json(httpConn.getInputStream());
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "";
    }

    private static String ConvertStream2Json(InputStream inputStream) {
        String jsonStr = "";
        // ByteArrayOutputStream相当于内存输出流
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len = 0;
        // 将输入流转移到内存输出流中
        try {
            while ((len = inputStream.read(buffer, 0, buffer.length)) != -1) {
                out.write(buffer, 0, len);
            }
            // 将内存流转换为字符串
            jsonStr = new String(out.toByteArray());
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return jsonStr;
    }
}