以下实例演示了如何获取指定 url 的响应头信息：
/* author by w3cschool.cc main.java */import java.io.ioexception;import java.net.url;import java.net.urlconnection;import java.util.map;import java.util.set;public class main { public static void main(string[] args) throws ioexception{ url url = new url("http://www.w3cschool.cc"); urlconnection conn = url.openconnection(); map headers = conn.getheaderfields(); set<string> keys = headers.keyset(); for( string key : keys ){ string val = conn.getheaderfield(key); system.out.println(key+" "+val); } system.out.println( conn.getlastmodified() ); }}
以上代码运行输出结果为：
transfer-encoding chunked null http/1.1 200 ok server tengine/1.3.0 connection keep-alive vary cookie date mon, 04 may 2015 03:54:05 gmt x-pingback x-powered-by php/5.3.15 content-type text/html; charset=utf-8
以上就是java 实例 - 获取 url 响应头信息的内容。