HttpServletRequest对象方法的用法

1. 获得客户机信息
    getRequestURL方法返回客户端发出请求时的完整URL。
    getRequestURI方法返回请求行中的资源名部分。
    getQueryString 方法返回请求行中的参数部分。
    getRemoteAddr方法返回发出请求的客户机的IP地址 
    getRemoteHost方法返回发出请求的客户机的完整主机名
    getRemotePort方法返回客户机所使用的网络端口号
    getLocalAddr方法返回WEB服务器的IP地址。
    getLocalName方法返回WEB服务器的主机名 
    getMethod得到客户机请求方式
 2.获得客户机请求头 

    getHeader(string name)方法 
    getHeaders(String name)方法 
    getHeaderNames方法 

 3. 获得客户机请求参数(客户端提交的数据)
    getParameter(name)方法
    getParameterValues（String name）方法
    getParameterNames方法 
    getParameterMap方法

例子程序:

 public void doGet(HttpServletRequest request, HttpServletResponse response)
         throws ServletException, IOException {
         System.out.println("getRequestURL: "+request.getRequestURL());
         System.out.println("getRequestURI: "+request.getRequestURI());
         System.out.println("getQueryString: "+request.getQueryString());
         System.out.println("getRemoteAddr: "+request.getRemoteAddr());
         System.out.println("getRemoteHost: "+request.getRemoteHost());
         System.out.println("getRemotePort: "+request.getRemotePort());
         System.out.println("getRemoteUser: "+request.getRemoteUser());
         System.out.println("getLocalAddr: "+request.getLocalAddr());
         System.out.println("getLocalName: "+request.getLocalName());
         System.out.println("getLocalPort: "+request.getLocalPort());
         System.out.println("getMethod: "+request.getMethod());
         System.out.println("-------request.getParamterMap()-------");
         //得到请求的参数Map，注意map的value是String数组类型
         Map map = request.getParameterMap();
         Set<String> keySet = map.keySet();
         for (String key : keySet) {
         String[] values = (String[]) map.get(key);
         for (String value : values) {
             System.out.println(key+"="+value);
         }
      }
         System.out.println("--------request.getHeader()--------");
         //得到请求头的name集合
         Enumeration<String> em = request.getHeaderNames();
         while (em.hasMoreElements()) {
         String name = (String) em.nextElement();
         String value = request.getHeader(name);
         System.out.println(name+"="+value);
     }

 }

浏览器上地址栏：http://localhost:8080/RequestAndResponse/requestmethod?name=sunjob&password=123456&password=haha

控制台输出：

 getRequestURL: http://localhost:8080/RequestAndResponse/requestmethod
 getRequestURI: /RequestAndResponse/requestmethod
 getQueryString: name=sunjob&password=123456&password=haha
 getRemoteAddr: 127.0.0.1
 getRemoteHost: 127.0.0.1
 getRemotePort: 2374
 getRemoteUser: null
 getLocalAddr: 127.0.0.1
 getLocalName: localhost
 getLocalPort: 8080
 getMethod: GET
 -------request.getParamterMap()-------
 name=sunjob
 password=123456
 password=haha
 --------request.getHeader()--------
 host=localhost:8080
 user-agent=Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20100101 Firefox/17.0
 accept=text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
 accept-language=zh-cn,en-us;q=0.8,zh;q=0.5,en;q=0.3
 accept-encoding=gzip, deflate
 connection=keep-alive
 cache-control=max-age=0