【Head First Servlets and JSP】笔记10：请求分派（RequestDispatcher）

package com.example.web;

import com.example.model.BeerExpert;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;

public class BeerSelect extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String c = req.getParameter("color");

        BeerExpert be = new BeerExpert();
        List result = be.getBrands(c);

        req.setAttribute("styles", result); // 为请求增加一个属性，供JSP使用。

        RequestDispatcher view = req.getRequestDispatcher("result.jsp"); // 为JSP实例化一个请求分派器

        view.forward(req, resp); // 使用请求分派器要求容器准备好JSP，并向JSP发送请求和响应
    }
}