bookdaoimpl.java

简易的网上书城主要用于初学者理解

package org.netbook.dao.impl;

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

import org.netbook.dao.BookDao;
import org.netbook.model.Book;
import org.netbook.utils.DBUtils;

public class BookDaoImpl implements BookDao {

	public List<Book> getAllBooks() {
		Connection conn = DBUtils.getConnection();
		PreparedStatement pStmt = null;
		ResultSet rs = null;
		List<Book> result = new ArrayList<Book>();
		final String SQL = "SELECT * FROM BOOKS ORDER BY ID DESC";
		try {
			pStmt = conn.prepareStatement(SQL);
			rs = pStmt.executeQuery();
			while (rs.next()) {
				Book book = new Book();
				book.setId(rs.getLong("ID"));
				book.setTitle(rs.getString("TITLE"));
				book.setPrice(rs.getBigDecimal("PRICE"));
				book.setPublishDate(rs.getDate("PUBLISHDATE"));
				book.setAuthor(rs.getString("AUTHOR"));
				result.add(book);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				if (rs != null) {
					rs.close();
				}
				if (pStmt != null) {
					pStmt.close();
				}
				if (conn != null) {
					conn.close();
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return result;
	}

	public void addBook(Book book) {
		Connection conn = DBUtils.getConnection();
		PreparedStatement pStmt = null;
		final String SQL = "INSERT INTO BOOKS(TITLE,AUTHOR,PRICE,PUBLISHDATE,content) VALUES(?,?,?,?,?)";
		try {
			pStmt = conn.prepareStatement(SQL);
			pStmt.setString(1, book.getTitle());
			pStmt.setString(2, book.getAuthor());
			pStmt.setBigDecimal(3, book.getPrice());
			pStmt
					.setDate(4, new java.sql.Date(book.getPublishDate()
							.getTime()));		
			pStmt.setString(5, book.getContent());
			pStmt.executeUpdate();
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				if (pStmt != null) {
					pStmt.close();
				}
				if (conn != null) {
					conn.close();
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

	}

	public Book getBookById(Long id) {
		Connection conn = DBUtils.getConnection();
		PreparedStatement pStmt = null;
		ResultSet rs = null;
		Book result = null;
		final String SQL = "SELECT * FROM BOOKS WHERE ID = ?";
		try {
			pStmt = conn.prepareStatement(SQL);
			pStmt.setLong(1, id);
			rs = pStmt.executeQuery();
			while (rs.next()) {
				result = new Book();
				result.setId(rs.getLong("ID"));
				result.setTitle(rs.getString("TITLE"));
				result.setPrice(rs.getBigDecimal("PRICE"));
				result.setPublishDate(rs.getDate("PUBLISHDATE"));
				result.setAuthor(rs.getString("AUTHOR"));
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				if (rs != null) {
					rs.close();
				}
				if (pStmt != null) {
					pStmt.close();
				}
				if (conn != null) {
					conn.close();
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return result;
	}

}