Servlet------>request

request细节一----->通过request获取ip

/**
 * Servlet request常用方法
 */
@WebServlet("/RequestDemo1")
public class RequestDemo1 extends HttpServlet {
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//页面访问次数，拦截访问
		System.out.println(request.getRequestURI());//很常见
		System.out.println(request.getRequestURL());
		System.out.println(request.getQueryString());//得到查询信息也就是http://www.snowing.com?name=1
		//得到name=1
		System.out.println(request.getRemoteAddr());//得到访问者ip地址
		System.out.println(request.getRemoteHost());//得到访问者主机名---》如果没在dns上注册就打印主机名 
		System.out.println(request.getRemotePort());//得到访问者端口(随机的)
		System.out.println(request.getLocalAddr());//返回web服务器的主机地址
		System.out.println(request.getLocalName());//返回web服务器的主机名---》如果没在dns上注册就打印主机名 
		System.out.println(request.getMethod());//得到客户机请求方式
		
		
		
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}

}

结果：访问：http://localhost:8082/day05/RequestDemo1?name=1

request细节二----->通过request获取头信息

request细节三----->通过request获取请求头数据

request细节四----->通过request控制编码问题

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//        request.setCharacterEncoding("UTF-8");//只有post生效
        String username=new String(request.getParameter("username").getBytes("iso8859-1"),"UTF-8");
        //反向查找，get／post都可以
        //URLEncoder.encode(username, "UTF-8");
        System.out.println(username);
    }

<meta charset="UTF-8">

另一种处理方式，在uri里带参数的情况，可以在tomcat server.xml里配置

post和get都通用的乱码配置情况：

servlet里配置：

server.xml:

request细节四----->MVC模式（model=javabean view=jsp controller=servlet）

jsp：

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
${data} 
<%
   String data=(String) request.getAttribute("data");
   out.write(data);
%>
</body>
</html>

servlet：

/**
 * 请求转发，以及使用request域对象把数据带给转发资源
 */
@WebServlet("/RequestDemo3")
public class RequestDemo3 extends HttpServlet {
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		String data="aaaa";
		request.setAttribute("data", data);
		request.getRequestDispatcher("/1.jsp").forward(request, response);//把数据转发给jsp，并显示
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

转发不能在response关闭后转发，所以一定记得，return！！！

//forward会清空response中的数据

页头和页脚总一样就用这种方式：

注意：head.jsp和foot.jsp要这样

posted on 2017-04-05 14:19 Snowing杨雪莹阅读(181) 评论(0) 收藏举报