HttpClient设置HTTP请求头Header

用Firebug对POST的数据进行监控 请求 HTTP头 信息,得到如下内容:

Java代码


Accept application/json, text/javascript, */*

Accept-Encoding gzip, deflate

Accept-Language en-us,en;q=0.5

Cache-Control no-cache

Content-Length 432

Content-Type application/x-www-form-urlencoded; charset=UTF-8

Host www.huaxixiang.com

Pragma no-cache

Proxy-Connection keep-alive

Refere http://www.huaxixiang.com/CrossPriceDetail.action
User-Agent Mozilla/5.0 (Windows NT 5.1; rv:11.0) Gecko/20100101 Firefox/11.0

X-Requested-With XMLHttpRequest

用HttpClient模仿浏览器访问页面,加载URL的HTML信息,为了良好的加载网站的信息,不被限制.

为了说明请求头的信息添加了一个小测试项目LoginTest,添加页面index.jsp,添加主要代码打印Http Header的JSP页面.

主要打印Http Header信息.

1. index.jsp

Java代码


out.println("Protocol: " + request.getProtocol());

out.println("Scheme: " + request.getScheme());

out.println("Server Name: " + request.getServerName() );

out.println("Server Port: " + request.getServerPort());

out.println("Protocol: " + request.getProtocol());

out.println("Server Info: " + getServletConfig().getServletContext().getServerInfo());

out.println("Remote Addr: " + request.getRemoteAddr());

out.println("Remote Host: " + request.getRemoteHost());

out.println("Character Encoding: " + request.getCharacterEncoding());

out.println("Content Length: " + request.getContentLength());

out.println("Content Type: "+ request.getContentType());

out.println("Auth Type: " + request.getAuthType());

out.println("HTTP Method: " + request.getMethod());

out.println("Path Info: " + request.getPathInfo());

out.println("Path Trans: " + request.getPathTranslated());

out.println("Query String: " + request.getQueryString());

out.println("Remote User: " + request.getRemoteUser());

out.println("Session Id: " + request.getRequestedSessionId());

out.println("Request URI: " + request.getRequestURI());

out.println("Servlet Path: " + request.getServletPath());

out.println("Accept: " + request.getHeader("Accept"));

out.println("Host: " + request.getHeader("Host"));

out.println("Referer : " + request.getHeader("Referer"));

out.println("Accept-Language : " + request.getHeader("Accept-Language"));

out.println("Accept-Encoding : " + request.getHeader("Accept-Encoding"));

out.println("User-Agent : " + request.getHeader("User-Agent"));

out.println("Connection : " + request.getHeader("Connection"));

out.println("Cookie : " + request.getHeader("Cookie"));

out.println("Created : " + session.getCreationTime());

out.println("LastAccessed : " + session.getLastAccessedTime());

2. 使用IE浏览器加载http://127.0.0.1:8080/LoginTest/index.jsp返回内容如下:

Java代码


Protocol: HTTP/1.1

Scheme: http

Server Name: 127.0.0.1

Server Port: 8080

Protocol: HTTP/1.1

Server Info: Apache Tomcat/6.0.18

Remote Addr: 127.0.0.1

Remote Host: 127.0.0.1

Character Encoding: null

Content Length: -1

Content Type: null

Auth Type: null

HTTP Method: GET

Path Info: null

Path Trans: null

Query String: null

Remote User: null

Session Id: E2C384C095E34AD355684EB554517FB1

Request URI: /LoginTest/index.jsp

Servlet Path: /index.jsp

Accept: */*

Host: 127.0.0.1:8080

Referer : null

Accept-Language : en-us

Accept-Encoding : gzip, deflate

User-Agent : Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.3; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET4.0C; .NET4.0E)

Connection : Keep-Alive

Cookie : JSESSIONID=E2C384C095E34AD355684EB554517FB1

Created : 1322294859981

LastAccessed : 1322294859981

3. 后面使用HttpClient不设置header信息加载http://127.0.0.1:8080/LoginTest/index.jsp信息如下:

Java代码


Protocol: HTTP/1.1

Scheme: httpServer

Name: 127.0.0.1

Server Port: 8080

Protocol: HTTP/1.1

Server Info: Apache Tomcat/6.0.18

Remote Addr: 127.0.0.1

Remote Host: 127.0.0.1

Character Encoding: null

Content Length: -1

Content Type: null

Auth Type: null

HTTP Method: GET

Path Info: null

Path Trans: null

Query String: null

Remote User: null

Session Id: null

Request URI: /LoginTest/index.jspServlet

Path: /index.jsp

Accept: null

Host: 127.0.0.1:8080

Referer : null

Accept-Language : null

Accept-Encoding : null

User-Agent : Apache-HttpClient/4.1.1 (java 1.5)

Connection : Keep-Alive

Cookie : null

Created : 1322293843369

LastAccessed : 1322293843369

分析: 由于这里纯粹加载页面,没有动用CookieStore自动管理Cookie,在上面没有能显示Cookie,SessionID的信息,区别于浏览器的的User-Agent,Cookie,SessionID,Accept,Accept-Language,Accept-Encoding等信息都没有进行设置.

对于爬取网站在HttpClient中设置Host,Referer,User-Agent,Connection,Cookie和爬取的频率和入口Url有讲究.

4. 考虑设置HttpClient的Header信息代码:

Java代码


HashMap<String, String> headers = new HashMap<String, String>();

headers.put("Referer", p.url);

headers.put("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.2.6) Gecko/20100625

Firefox/3.6.6 Greatwqs");

headers.put("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");

headers.put("Accept-Language","zh-cn,zh;q=0.5");

headers.put("Host","www.yourdomain.com");

headers.put("Accept-Charset","ISO-8859-1,utf-8;q=0.7,*;q=0.7");

headers.put("Referer", "http://www.yourdomian.com/xxxAction.html");

HttpRequestBase httpget = ......

httpget.setHeaders(headers);

5. 由新的HttpClient执行http://127.0.0.1:8080/LoginTest/index.jsp得到的HTML信息如下:

Java代码


Protocol: HTTP/1.1

Scheme: http

Server Name: www.yourdomain.com

Server Port: 80

Protocol: HTTP/1.1

Server Info: Apache Tomcat/6.0.18

Remote Addr: 127.0.0.1

Remote Host: 127.0.0.1

Character Encoding: null

Content Length: -1

Content Type: null

Auth Type: null

HTTP Method: GET

Path Info: null

Path Trans: null

Query String: null

Remote User: null

Session Id: null

Request URI: /LoginTest/index.jsp

Servlet Path: /index.jsp

Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Host: www.yourdomain.com

Referer : http://www.yourdomian.com/xxxAction.html
Accept-Language : zh-cn,zh;q=0.5

Accept-Encoding : null

User-Agent : Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.2.6) Gecko/20100625 Firefox/3.6.6

Greatwqs

Connection : Keep-Alive

Cookie : null

Created : 1322294148709

LastAccessed : 1322294148709