bookdao.java

网上书店 。根据对网上书店系统的需求分析

package dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import entity.Book;

public class BookDao {

	public BookDao() {
	}

	/**
	 * 获取全部书本
	 * 
	 * @return
	 * @throws SQLException
	 */
	public List<Book> findAll() throws SQLException {
		List<Book> booklist = new ArrayList<Book>();
		String sql = "select isbn,title,description,price,image from Books";

		Connection conn = DaoUtil.getConnection();
		try {
			PreparedStatement ps = conn.prepareStatement(sql);

			ResultSet rs = ps.executeQuery();
			while (rs.next()) {
				Book book = new Book();
				book.setIsbn(rs.getString("isbn"));
				book.setImagePath(rs.getString("image"));
				book.setDesc(rs.getString("description"));
				book.setPrice(rs.getDouble("price"));
				book.setTitle(rs.getString("title"));
				booklist.add(book);
			}
		} finally {
			DaoUtil.closeConnection(conn);
		}
		return booklist;
	}

	public static void main(String[] args) throws SQLException {
		System.out.println(new BookDao().findAll().size());
	}

	public Book findByIsbn(String isbn) throws SQLException {
		Book book = null;
		String sql = "select isbn,title,description,price,image from Books where isbn= ?";

		Connection conn = DaoUtil.getConnection();
		try {
			PreparedStatement ps = conn.prepareStatement(sql);
			ps.setString(1, isbn);
			ResultSet rs = ps.executeQuery();
			if (rs.next()) {
				book = new Book();
				book.setIsbn(rs.getString("isbn"));
				book.setImagePath(rs.getString("image"));
				book.setDesc(rs.getString("description"));
				book.setPrice(rs.getDouble("price"));
				book.setTitle(rs.getString("title"));
			}
		} finally {
			DaoUtil.closeConnection(conn);
		}
		return book;
	}
}