学步园

         使用jsp+servlet时，有些代码期待写在servlet中，而在jsp程序中尽量写页面代码，像在注册的时候，注册成功时要显示信息的时候，这些代码可以在jsp中通过Java代码显示，也可以在servlet中显示，可是使用servlet到jsp页面的跳转语句时，就不会显示servlet页面的内容啦，这时我们可以借助Response中的刷新头，使页面停留一些时间，然后调转到jsp页面，这样servlet中的内容也可以显示啦，看一下代码：

package com.you.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.you.bean.UserBean;
import com.you.domain.Domain;

public class RegisteServlet extends HttpServlet {
	private String name;
	private String word;
	private String sex;
	private String birth;
	private String email;
	private String address;

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		response.setContentType("text/html;charset=UTF-8");
		request.setCharacterEncoding("UTF-8");
		UserBean userBean = new UserBean();
		userBean.setUsername(request.getParameter("username"));
		userBean.setPassword(request.getParameter("userpassword"));
		userBean.setSex(request.getParameter("sex"));
		String year = request.getParameter("year");
		String month = request.getParameter("month");
		String day = request.getParameter("day");
		userBean.setBirth(year + "年" + month + "月" + day + "日");
		userBean.setEmail(request.getParameter("email"));
		userBean.setAddress(request.getParameter("address"));
        request.getSession().setAttribute("user", userBean);
        name = userBean.getUsername();
        word = userBean.getPassword();
        sex = userBean.getSex();
        birth = userBean.getBirth();
        email = userBean.getEmail();
        address = userBean.getAddress();
        
		Domain myDo = new Domain();
		myDo.insert(name, word, sex, birth, email, address);
 
		PrintWriter out = response.getWriter();
        out.print(name+"<br/>");
        out.print(word+"<br/>");
        out.print(sex+"<br/>");
        out.print(birth+"<br/>");
        out.print(email+"<br/>");
        out.print(address);
        
		response.setHeader("refresh", "5;URL=http://localhost:8080/Login_5/register.jsp");
		
		
	}
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}

       浏览器实现缓存的话，这样不能实现信息的及时更新，可以通过禁止浏览器缓存头。看一下代码：

package com.you.servlet;

import java.io.IOException;

public class CacheTestServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		response.setContentType("text/html;charset=utf-8");
		response.setDateHeader("Expires", 0);
		response.setHeader("Cache-Control", "no-cache");
		response.setHeader("Prama", "no-cache");
		
		PrintWriter out = response.getWriter();
		out.println("本次响应的随机数为：" + Math.random());
		out.println("<form action='NotServlet'" + "method='post'"
				+"第一个参数：<input type='text' name='p1'><br/>" + 
				"第二个参数：<textarea name='p2'></textarea><br/>" +
				"<input type='submit' value='提交'>" +
				"</form>");

	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}

上面的三句都是禁止浏览器缓存的头，因为担心有些浏览器不识别，所以三种类型的都写上，这样就都会实现啦。