IT程序员开发必备-各类资源下载清单，史上最全IT资源，个人收藏总结！
请求头
Accept:text/html,image 用于告诉服务器， 客户机支持的数据类型
Accept-Charaset:ISO-8859-1 客户机支持的编码
Accept-Encoding:gzip 客户机支持的数据压缩格式
Accept-Language: zh-cn 客户机支持的语言
Host:www.t381.org 告诉服务器，想访问的主机名
Referer:http://www.ti23.org 从哪个资源访问服务器（常用于防盗链）
User-Agent:Mozilla 4.0 告诉客户机的软件环境
Cookie:可以带给服务器客户端的数据
Connection:close/Keep-Alive 请求后是关闭，还是保持连接
Date: Tue, 11 Jul 2000 18:30:30 GMT 请求时间
响应头
HTTP/1.1 200 OK 状态行，200是状态码表示一切OK
Location:
http://www.aaa.net 配合http302状态码实现重定向，告诉客户机应该找谁
Server: Microsoft-IIS/5.0 告诉浏览器服务器的类型
Content-Encoding:gzip 数据的压缩格式
Content-Length:告诉浏览器，回送数据的长度
Content-Type: text/html; charset=utf-8 告诉浏览器，回送数据的类型
Transfer-Encoding:告诉浏览器数据的传送格式
Refresh:多长时间之后刷新一次
Last-Modified: 告诉浏览器当前资源的缓存时间点
Content-Disposition:"attachment;filename=mother.jpg" 控制让浏览器用下载的方式访问资源
Connection:close/Keep-Alive
Date: Sun, 23 Sep 2012 13:03:14 GMT
Expires:告诉浏览器把回送的资源缓存多长时间。-1或0，则表示不缓存,单位为毫秒，如缓存1小时:
response.setDateHeader("Expires", System.currentTimeMillis()+1000*3600);
Cache-Contorl: no-cache或max-age=1800 控制浏览器的缓存
Pragma: no-cache
注意：后三个都可以实现是否缓存以及缓存多久，但是不同浏览器对其支持不同，所以如果想要不缓存，则可以三者都设置一下，以支持所有浏览器
location 响应头的用法:
//用location响应头和状态码302实现请求重定向
private void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//和下句代码可互换位置,此两行相当于response.sendRedirect("");
response.setStatus(302);
//或者"location.jsp"
response.setHeader("location","/HTTPHeader/location.jsp");
}
则在浏览器上输入:http://localhost:8080/HTTPHeader/header,会跳转至http://localhost:8080/HTTPHeader/location.jsp页面。
用HttpWatch检测得到的响应头信息:
HTTP/1.1 302 Moved Temporarily
Server: Apache-Coyote/1.1
location: location.jsp
Content-Length: 0
Date: Fri, 23 Dec 2011 13:36:23 GMT
Content-Encoding 响应头的用法:
//压缩数据输出：
private void contentEncoding(HttpServletRequest request,
HttpServletResponse response) throws IOException {
String data = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" +
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" +
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" +
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" +
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" +
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" +
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" +
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
System.out.println("原始数据大小："+data.getBytes().length);
ByteArrayOutputStream bout = new ByteArrayOutputStream();
//包装输出流
GZIPOutputStream gout = new GZIPOutputStream(bout);
gout.write(data.getBytes());
/*
* 调用该方法或gout.flush()后，GZIPOutputStream才会将经过压缩的data.getBytes()字节
* 数组写入ByteArrayOutputStream
*/
gout.close();
byte gzip[] = bout.toByteArray();
System.out.println("压缩后的大小："+gzip.length);
//通知浏览器数据采用压缩格式
response.setHeader("Content-Encoding", "gzip");
//通过浏览器会送数据的长度
response.setHeader("Content-Length", gzip.length+"");
response.getOutputStream().write(gzip);
}
后台打印:
原始数据大小：666
压缩后的大小：27
用HttpWatch检测得到的响应头信息:
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Content-Encoding: gzip
Content-Length: 27
Date: Fri, 23 Dec 2011 13:59:30 GMT
?????????
Content-type 响应头的用法:
//通过Content-Type控制以哪种方式处理数据
private void contentType(HttpServletRequest request,HttpServletResponse response) throws IOException {
/**
* 关于Content-Type响应头的取值：可以参考...\Tomcat 6.0\conf\web.xml
<mime-mapping>
<extension>jpg</extension>
<mime-type>image/jpeg</mime-type>
</mime-mapping>
**/
response.setHeader("Content-type", "image/jpeg");
InputStream in = this.getServletContext().getResourceAsStream("/mother.jpg");
int len = 0;
byte buffer[] = new byte[1024];
OutputStream out = response.getOutputStream();
while ((len=in.read(buffer))>0) {
out.write(buffer,0,len);
}
用HttpWatch检测得到的响应头信息:
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Content-Type: image/jpeg
Transfer-Encoding: chunked
Date: Fri, 23 Dec 2011 14:18:10 GMT
Refresh响应头的用法:
//定时刷新
private void refresh(HttpServletRequest request,
HttpServletResponse response) throws IOException {
//每隔3秒刷新一次当前页面
// response.setHeader("Refresh", "3");
//3秒后跳转至本工程下的mother.jpg下，地址栏会变，重定向技术
response.setHeader("Refresh", "3;url='/HTTPHeader/mother.jpg'");
String data = "aaaaaaaaaaaaaaaaaaaaaa";
response.getOutputStream().write(data.getBytes());
}
Content-Disposition响应头的用法:
//控制让浏览器用下载的方式访问资源
private void contentDisposition(HttpServletRequest request,
HttpServletResponse response) throws IOException {
//控制让浏览器用下载的方式访问资源
response.setHeader("Content-Disposition", "attachment;filename=mother.jpg");
InputStream in = this.getServletContext().getResourceAsStream("mother.jpg");
int len = 0;
byte[] buffer = new byte[1024];
OutputStream out = response.getOutputStream();
while ((len=in.read(buffer))>0) {
out.write(buffer,0,len);
}
}
用HttpWatch检测得到的响应头信息:
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Content-Disposition: attachment;filename=mother.jpg
Transfer-Encoding: chunked
Date: Fri, 23 Dec 2011 14:41:18 GMT
IT程序员开发必备-各类资源下载清单，史上最全IT资源，个人收藏总结！