productlistservlet.java

使用jsp+Servlet,采用MVC模式,实现了一典型小型电子商务网站的全过程.包括前台和后台的全部功能.适合于初学者学习使用.

package com.eshop.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Vector;

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

import com.eshop.page.PageBean;
import com.eshop.page.PageBusiness;
import com.eshop.page.ProductPage;

public class ProductListServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public ProductListServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
			doPost(request,response);
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
			
		response.setContentType("text/html; charset=gb2312");
		PrintWriter out = response.getWriter();

		boolean done = false;//是否还需要构造搜索条件语句
		//获得conditions参数
		String conditions = (String) request.getParameter("conditions");
		//如果用户不是第一次输入搜索条件，而是点击了next之类的连接，那么conditions参数不是空。
		if (!"".equals(conditions) && conditions != null) {
			done = true;
		}
		//没有conditions参数，说明是第一次输入搜索条件，然后需要构造conditions参数。		
		else {
			String keyword = (String) request.getParameter("keyword");
			String searchType = (String) request.getParameter("searchType");
			//将从输入的参数是否合法
			if (keyword != null
					&& (keyword.length() > 40 || keyword.length() < 3)) {
				out.println("key words to short or to long!");
				out.println("<a href=" + request.getRequestURI() + ">返回</a>");
			} else {
				//构造conditions搜索条件
				conditions = searchType + " like '%" + keyword + "%' ";
			}
		}
		try {
			PageBusiness pb = new ProductPage();
			String page = (String) request.getParameter("jumpPage");
			try {
				if (page.equals("") || page.equals(null))
					page = "1";
			} catch (Exception e) {
				page = "1";
			}
			//读取数据的结果集
			PageBean pageCtl = pb.listData(page, conditions);
			Vector vector=pageCtl.getResult();
			//读取当前页的值
			String curPage=String.valueOf(pageCtl.curPage);
			//读取最大值
			String maxPage=String.valueOf(pageCtl.maxPage);
			//最大行数
			String maxRowCount=String.valueOf(pageCtl.maxRowCount);
			//第页的行数
			String rowsPerPage=String.valueOf(pageCtl.rowsPerPage);
			//最大页数
			//String maxPage=String.valueOf(pageCtl.countMaxPage());
			//将查询结果存储到REQUEST对象中
			request.setAttribute("list", vector);
			
			//把PageBean保存到request对象中。
			request.setAttribute("curPage", curPage);
			request.setAttribute("maxPage",maxPage);
			request.setAttribute("maxRowCount", maxRowCount);
			request.setAttribute("rowsPerPage", rowsPerPage);
			request.setAttribute("conditions", conditions);
//			request.setAttribute("page", pageCtl);
		} catch (Exception e) {
			out.println("发生异常：!" + e.getMessage());
			out.println("<a href=" + request.getRequestURI() + ">返回</a>");

		}
		/**
		 *把视图派发到productList.jsp
		 */
		RequestDispatcher dis=request.getRequestDispatcher("/product/productList.jsp");
		 dis.forward(request, response);
			
			
	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}