本文实例讲述了JAVA获取HTTP请求头的方法。分享给大家供大家参考，具体如下：
在利用Java网络编程时，利用Java获取HTTP Request 和 Response头字段；
可以利用Java语言根据需要添加自定义的HTTP头字段，而不必拘泥于标准HTTP定义的头字段。
代码如下：
public class TestURL { public static void main(String[] args) { String destURLStr= "http://www.baidu.com"; URL destURL = null; URLConnection urlCon = null; HttpURLConnection httpUrlCon= null; String readResFile = "C:/Users/zhoujw/Desktop/readResFile.html"; BufferedWriter bw = null; try { bw = new BufferedWriter(new FileWriter(readResFile)); destURL = new URL(destURLStr); urlCon = destURL.openConnection(); httpUrlCon = (HttpURLConnection)urlCon; //set request property httpUrlCon.setRequestProperty("Accept-Encoding", "gzip,deflate,sdch"); //可根据需要添加自定义请求头 httpUrlCon.setRequestProperty("Test Header1", "test1"); httpUrlCon.setRequestProperty("Test Header2", "test2"); httpUrlCon.connect(); BufferedReader br = new BufferedReader(new InputStreamReader(httpUrlCon.getInputStream(), "gbk")); String webpage = null; while((( webpage = br.readLine()) != null)) {// System.out.println(webpage); bw.write(webpage); bw.flush(); } //debug System.out.println("Self Define Headers:"); System.out.println(" Test Header1: " + httpUrlCon.getRequestProperty("Test Header1")); System.out.println(" Test Header2: " + httpUrlCon.getRequestProperty("Test Header2")); System.out.println(); //echo request property echoRequestHeaders(httpUrlCon); //echo response property echoResponseHeaders(httpUrlCon); } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } public static void echoRequestHeaders(HttpURLConnection httpUrlCon){ System.out.println("Request Headers:"); System.out.println(" " + httpUrlCon.getRequestMethod() + " / " + " HTTP/1.1"); System.out.println(" Host: " + httpUrlCon.getRequestProperty("Host")); System.out.println(" Connection: " + httpUrlCon.getRequestProperty("Connection")); System.out.println(" Accept: " + httpUrlCon.getRequestProperty("Accept")); System.out.println(" User-Agent: " + httpUrlCon.getRequestProperty("User-Agent")); System.out.println(" Accept-Encoding: " + httpUrlCon.getRequestProperty("Accept-Encoding")); System.out.println(" Accept-Language: " + httpUrlCon.getRequestProperty("Accept-Language")); System.out.println(" cookie: " + httpUrlCon.getRequestProperty("cookie")); System.out.println(" Connection: " + httpUrlCon.getHeaderField("Connection"));//利用另一种读取HTTP头字段 System.out.println(); } public static void echoResponseHeaders(HttpURLConnection httpUrlCon) throws IOException{ System.out.println("Response Headers:"); System.out.println(" " + "HTTP/1.1 " + httpUrlCon.getResponseCode() + " " + httpUrlCon.getResponseMessage()); System.out.println(" status: " + httpUrlCon.getResponseCode() + " " + httpUrlCon.getResponseMessage()); System.out.println(" content-encoding: " + httpUrlCon.getContentEncoding()); System.out.println(" content-length : " + httpUrlCon.getContentLength()); System.out.println(" content-type: " + httpUrlCon.getContentType()); System.out.println(" Date: " + httpUrlCon.getDate()); System.out.println(" ConnectTimeout: " + httpUrlCon.getConnectTimeout()); System.out.println(" expires: " + httpUrlCon.getExpiration()); System.out.println(" content-type: " + httpUrlCon.getHeaderField("content-type"));//利用另一种读取HTTP头字段 System.out.println(); }}运行结果：
Self Define Headers: Test Header1: test1 Test Header2: test2Request Headers: GET / HTTP/1.1 Host: www.baidu.com Connection: keep-alive Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2 User-Agent: Java/1.6.0_20 Accept-Encoding: gzip,deflate,sdch Accept-Language: null cookie: null Connection: Keep-Alivehttp://www.baidu.comResponse Headers: HTTP/1.1 200 OK status: 200 OK content-encoding: gzip content-length : -1 content-type: text/html; charset=utf-8 Date: 1427817028000 ConnectTimeout: 0 expires: 1427817001000 content-type: text/html; charset=utf-8
