url 重写实现会话概述
URL重写是对GET请求参数的应用，当服务器响应浏览器上一次请求时，将某些相关信息以超链接方式响应给浏览器，超链接中包括请求参数信息。
特点：URL必须以GET方式发送请求。
缺点：URL在某些浏览器上最大长度为2000字符；不适用敏感数据的传递。
应用：最典型应用是分页、辅助Session会话管理。
example
package com.test; import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter; @WebServlet("/search")
public class Search extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html; charset=UTF-8");
PrintWriter out = response.getWriter(); out.println("<!DOCTYPE html>");
out.println("<html>");
out.println("<head>");
out.println("<meta charset='UTF-8'>");
out.println("<title>搜索结果</title>");
out.println("</head>");
out.println("<body>"); String start = request.getParameter("start");
if (start == null) {
start = "1";
}
int count = Integer.parseInt(start);
int begin = 10 * count - 9;
int end = 10 * count;
out.println("第" + begin + "到" + end + "搜索结果：<br>");
for (int i=1; i<10; i++) {
if (i == count) {
out.println(i);
continue;
}
out.println("<a href='search?start=" + i + "'>" + i +"</a>");
}
out.println("</body>");
out.println("</html>");
out.close();
}
}
响应结果：