selectservlet.java

网上订餐系统的源码

package com.tx.web;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

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

import com.tx.common.DBM;
import com.tx.entity.Book;

public class SelectServlet extends HttpServlet {

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

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		String id = request.getParameter("id");

		if (id == null) {
			DBM dbm = new DBM();
			String sql = "select * from titles";
			ResultSet rs = dbm.executeQuery(sql);
			ArrayList list = new ArrayList();
			if (rs != null) {
				try {
					while (rs.next()) {
						Book book = new Book();
						book.setBookId(rs.getString("isbn"));
						book.setBookName(rs.getString("title"));
						book.setCount(0);
						book.setPrice(rs.getFloat("price"));
						list.add(book);
					}
				} catch (SQLException e) {
					e.printStackTrace();
				} finally {
					dbm.closeConn();
				}
			}
			request.getSession().setAttribute("bookList", list);
			response.sendRedirect("bookList.jsp");
		} else {
			List list = (List) request.getSession().getAttribute("bookList");
			for (int i = 0; i < list.size(); i++) {
				Book book = (Book) list.get(i);
				if (book.getBookId().equals(id)) {
					request.setAttribute("oneBook", book);
					break;
				}
			}
			request.getRequestDispatcher("detail.jsp").forward(request,
					response);
		}
	}

}