java获取页面编码(Z)

文章出自：http://babyjoycry.javaeye.com/blog/587527 在此感谢原作者...\(^o^)/~

 

最近研究抓取网页内容，发现要获取页面的编码格式，Java没有现成的实现方法，虽然csdn上有个达人写了一篇文章，附有代码，可惜，我没有找到相关的包，不得已，只好自己动手丰衣足食了。

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import cpdetector.io.CodepageDetectorProxy;
import cpdetector.io.HTMLCodepageDetector;
import cpdetector.io.JChardetFacade;

public class PageEncodeDetector {
   private static CodepageDetectorProxy detector = CodepageDetectorProxy
      .getInstance();

   static {
    detector.add( new HTMLCodepageDetector( false));
    detector.add(JChardetFacade.getInstance());
  }

   /**
    * 测试用例
    *    
    * @param args
    */
   public static void main(String[] args) {
    PageEncodeDetector web = new PageEncodeDetector();
     try {
      System.out.println(web.getCharset( "http://www.baidu.com/"));
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }

  /**
    * @param strurl
    *                        页面url地址,需要以 http://开始，例：http://www.pujia.com
    * @return
    * @throws IOException
    */
  public String getCharset(String strurl) throws IOException {
    // 定义URL对象
    URL url = new URL(strurl);
    // 获取http连接对象
    HttpURLConnection urlConnection = (HttpURLConnection) url
        .openConnection();
    ;
    urlConnection.connect();
    // 网页编码
    String strencoding = null;

    /**
     * 首先根据header信息，判断页面编码
     */
    // map存放的是header信息(url页面的头信息)
    Map<String, List<String>> map = urlConnection.getHeaderFields();
    Set<String> keys = map.keySet();
    Iterator<String> iterator = keys.iterator();

    // 遍历,查找字符编码
    String key = null;
    String tmp = null;
    while (iterator.hasNext()) {
      key = iterator.next();
      tmp = map.get(key).toString().toLowerCase();
      // 获取content-type charset
      if (key != null && key.equals("Content-Type")) {
        int m = tmp.indexOf("charset=");
        if (m != -1) {
          strencoding = tmp.substring(m + 8).replace("]", "");
          return strencoding;
        }
      }
    }

    /**
     * 通过解析meta得到网页编码
     */
    // 获取网页源码(英文字符和数字不会乱码，所以可以得到正确<meta/>区域)
    StringBuffer sb = new StringBuffer();
    String line;
    try {
      BufferedReader in = new BufferedReader(new InputStreamReader(url
          .openStream()));
      while ((line = in.readLine()) != null) {
        sb.append(line);
      }
      in.close();
    } catch (Exception e) { // Report any errors that arise
      System.err.println(e);
      System.err
          .println("Usage:     java     HttpClient     <URL>     [<filename>]");
    }
    String htmlcode = sb.toString();
    // 解析html源码，取出<meta />区域，并取出charset
    String strbegin = "<meta";
    String strend = ">";
    String strtmp;
    int begin = htmlcode.indexOf(strbegin);
    int end = -1;
    int inttmp;
    while (begin > -1) {
      end = htmlcode.substring(begin).indexOf(strend);
      if (begin > -1 && end > -1) {
        strtmp = htmlcode.substring(begin, begin + end).toLowerCase();
        inttmp = strtmp.indexOf("charset");
        if (inttmp > -1) {
          strencoding = strtmp.substring(inttmp + 7, end).replace(
              "=", "").replace("/", "").replace("\"", "")
              .replace("\'", "").replace(" ", "");
          return strencoding;
        }
      }
      htmlcode = htmlcode.substring(begin);
      begin = htmlcode.indexOf(strbegin);
    }

    /**
     * 分析字节得到网页编码
     */
    strencoding = getFileEncoding(url);

    // 设置默认网页字符编码
    if (strencoding == null) {
      strencoding = "GBK";
    }

    return strencoding;
  }

  /**
    *    
    *<br>
    * 方法说明：通过网页内容识别网页编码
    *    
    *<br>
    * 输入参数：strUrl 网页链接; timeout 超时设置
    *    
    *<br>
    * 返回类型：网页编码
    */
  public static String getFileEncoding(URL url) {

    java.nio.charset.Charset charset = null;
    try {
      charset = detector.detectCodepage(url);
    } catch (Exception e) {
      System.out.println(e.getClass() + "分析" + "编码失败");
    }
    if (charset != null)
      return charset.name();
    return null;

  }

}

 

需要下载cpdetector_1.0.5.jar 和 chardet.jar