在利用Java网络编程时，常常需要获取HTTP请求头，那么JAVA如何获取HTTP请求头呢？下面小编为大家介绍了JAVA获取HTTP请求头的方法，希望能帮到大家！
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: test2
Request 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-Alive
http://www.baidu.com
Response 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
