Java中通過URLConnection獲取Http響應Header信息

本文中演示如何通過URLConnection獲取Http響應Header信息

1.從響應中獲得Header信息

URL obj = new URL("http://www.bianceng.cn");
URLConnection conn = obj.openConnection();
Map<String, List<String>> map = conn.getHeaderFields();

2.從響應Header中獲取Server信息

Map<String, List<String>> map = conn.getHeaderFields();
 List<String> server = map.get("Server");

完整的示例

package com.qiyadeng.http;
    
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;
     
public class GetHttpResponseHeader {
     
  public static void main(String[] args) {
     
        try {
     
                URL obj = new URL("http://www.bianceng.cn");
                URLConnection conn = obj.openConnection();
                Map<String, List<String>> map = conn.getHeaderFields();
     
                System.out.println("顯示響應Header信息...\n");
     
                for (Map.Entry<String, List<String>> entry : map.entrySet()) {
                        System.out.println("Key : " + entry.getKey() + 
                                           " ,Value : " + entry.getValue());
                }
     
                System.out.println("\n使用key獲得響應Header信息 \n");
                List<String> server = map.get("Server");
     
                if (server == null) {
                        System.out.println("Key 'Server' is not found!");
                } else {
                        for (String values : server) {
                                System.out.println(values);
                        }
                }
     
        } catch (Exception e) {
                e.printStackTrace();
        }
     
  }
     
}

輸出

顯示響應Header信息...

Key : null ,Value : [HTTP/1.1 200 OK]
Key : X-Pingback ,Value : [http://www.bianceng.cn/xmlrpc.php]
Key : Date ,Value : [Sun, 10 Mar 2013 12:16:26 GMT]
Key : Transfer-Encoding ,Value : [chunked]
Key : Connection ,Value : [close]
Key : Content-Type ,Value : [text/html; charset=UTF-8]
Key : Server ,Value : [Apache/2.2.3 (CentOS)]
Key : X-Powered-By ,Value : [PHP/5.2.17]
    
使用key獲得響應Header信息 ...
    
Apache/2.2.3 (CentOS)

出處：http://www.qiyadeng.com/