HttpClient使用
背景：因为想写一个测试tomcat连接的程序，就试试自已去构造Http请求。找了一下发现Apache下有一个比较成熟的轮子HttpComponets.
使用库：Apache Http Client
HttpClient是一个代码级的Http客户端工具,可以使用它模拟浏览器向Http服务器发送请求。
其中HttpClient是HttpComponents项目其中的一部份，HttpComponents简称为hc.
使用HttpClient还需要HttpCore.这里其中包括Http请求与Http响应的代码封装。
现在导入两个jar包:
httpclient-4.0.jar
httpcore-4.0.jar
httpmime-4.0.jar
开始一个请求代码如下:
HttpClient httpClient = new DefaultHttpClient();
//构造请求,如果想使用POST则new一个HttpPost
HttpGet get = new HttpGet("http://www.iteye.com");
HttpResponse response = httpClient.execute(get);
//先从响应头得到实体
HttpEntity entity = response.getEntity();
//得到实体输入流
InputStream inSm = entity.getContent();
Scanner inScn = new Scanner(inSm);
while(inScn.hasNextLine()){
System.out.println(inScn.nextLine());
}
entity.consumeContent();
这个是在HC例子中有代码作了少量的修改。
输出:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh-CN" dir="ltr">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>JavaEye Java编程 Spring框架 AJAX技术 Agile敏捷软件开发 ruby on rails实践 - JavaEye做最棒的软件开发交流社区</title>
<meta name="description" content="Java编程,Spring Struts Webwork框架深入,XMLHTTP AJAX开发,Java Web开发,Java企业应用,Java设计模式,Java开源框架,Java应用服务器,Rich Client讨论,Ruby编程,Ruby DSL开发,Ruby on rails实践,JavaScript编程,敏捷软件开发XP TDD,软件配置管理,软件测试,项目管理UML,数据库,C#/.net C/C++ Erlang/FP PHP/Linux平台,精通Hibernate" />
<meta name="keywords" content="Java编程 Spring框架 AJAX技术 Agile敏捷软件开发 ruby on rails实践 JavaEye深度技术社区" />
<link rel="shortcut icon" href="/images/favicon.ico" type="image/x-icon" />
<link href="/rss" rel="alternate" title="JavaEye技术网站RSS频道订阅" type="application/rss+xml" />
<link href="http://www.iteye.com/stylesheets/homepage.css?1263389049" media="screen" rel="stylesheet" type="text/css" />
</head>
...省略，证明以上代码已经成功
当然这个只是大刀一小试。现在还离我的目标差一点点：
需要做个头,我还不太清楚有什么头可以使用，那样我又写了个程序看看IE的头到底是怎样子的，
没有抓包程序，只好自已写个程序：
ServerSocket socketServer = new ServerSocket(10086);
Socket client = socketServer.accept();
InputStream inClient = client.getInputStream();
Scanner inScn = new Scanner(inClient);
while(inScn.hasNextLine()){
System.out.println(inScn.nextLine());
}
inScn.close();
client.close();
socketServer.close();
在IE地址栏上输入:
点确定后可以得到程序输出:
GET / HTTP/1.1 Accept: image/jpeg, application/x-ms-application, image/gif, application/xaml+xml, image/pjpeg, application/x-ms-xbap, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, application/x-shockwave-flash, */* Accept-Language: zh-CN User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; QQWubi 87; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0) Accept-Encoding: gzip, deflate Host: localhost:10086 Connection: Keep-Alive
分析请求包中这六个头信息。可以参考以下文章：
http://zsxxsz.iteye.com/blog/568250
现在我使用HC模拟IE的请求，修改后代码如下:
HttpClient httpClient = new DefaultHttpClient();
HttpGet get = new HttpGet("http://www.iteye.com");
get.setHeader("Accept", "image/jpeg, application/x-ms-application, image/gif, application/xaml+xml, image/pjpeg, application/x-ms-xbap, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, application/x-shockwave-flash, */*");
get.setHeader("Accept-Language","zh-CN");
get.setHeader("User-Agent","Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; QQWubi 87; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0)");
get.setHeader("Accept-Encoding","gzip, deflate");
get.setHeader("Host","you never be know");
get.setHeader("Connection","Keep-Alive");
HttpResponse response = httpClient.execute(get);