get the header content from some website, in java

最新推荐文章于 2025-10-13 14:23:19 发布

原创最新推荐文章于 2025-10-13 14:23:19 发布 · 467 阅读

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文章标签：

#website #header #url #string #equals #class

本文提供了一段Java代码示例，用于从指定网站抓取页面头部的元数据信息。通过解析HTTP响应头，该代码能够提取<meta>标签内容，并展示了一个具体实例。

just help one friend for writing some java code to access the meta data of the header of some website's response:

=====================================

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;

public class ReadWebsite {

/**
* @param args
*/
public static void main(String[] args) {
  int READ_BUFFER_SIZE = 1024;

  try
  {
   //make change to a different website, please edit here!
      //URL url = new URL("http://www.google.com/");
   URL url = new URL("http://java.sun.com/j2se/1.4.2/docs/api/java/lang/String.html");

      URLConnection urlConnection = url.openConnection();
      InputStream ins = urlConnection.getInputStream();
      InputStreamReader i = new InputStreamReader(ins);

      BufferedReader b = new BufferedReader(new InputStreamReader(ins));
      String oneLine = "", content = "", oneField;

      while ((oneLine = b.readLine()) != null)
      {
      content += oneLine;
      }

      int start = -1, end = -1;

      content = content.toUpperCase();

      start = content.indexOf("<META");

      while (start != -1)
      {
      content = content.substring(start);

      end = content.indexOf(">");
      if (end != -1)
      {
        oneField = content.substring(0, end + 1);
        System.out.println("/n");
        System.out.println(oneField);

        content = content.substring(end + 1);
      }

      start = content.indexOf("<META");
      }
  }
  catch (IOException e)
  {
   System.err.println("Error: " + e);
  }

}

}

======== output is as follows: