HttpServletRequest和ServletRequest的区别以及HttpServletRequest对象方法的用法
HttpServletRequest和ServletRequest都是接口
HttpServletRequest继承自ServletRequest
HttpServletRequest比ServletRequest多了一些针对于Http协议的方法。 例如：
getHeader()， getMethod() ， getSession()
@Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException { // 过滤用户请求，判断是否登录 HttpServletRequest httpServletRequest = (HttpServletRequest)request; HttpServletResponse httpServletResponse = (HttpServletResponse)response; httpServletResponse .setContentType("text/html;charset=utf-8"); httpServletRequest.setCharacterEncoding("utf-8"); httpServletResponse.setCharacterEncoding("utf-8"); String username = (String)httpServletRequest.getSession().getAttribute("username"); if (username == null) { String path = httpServletRequest.getContextPath(); httpServletResponse.sendRedirect(path+"/index.jsp"); } filterChain.doFilter(httpServletRequest, httpServletResponse); }
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