Java基于MVC模式的一个简单购物车实例源码+使用说明.zip

package pers.yus.javaweb.dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.HashMap; import pers.yus.javaweb.beans.Book; import pers.yus.javaweb.datasource.DataSourceUtil; public class DBUtils { private Connection conn = null; private Statement stm = null; private ResultSet rs = null; private PreparedStatement ps = null; // 获取所有数据 public HashMap<String, Book> getAllBook() { HashMap<String, Book> hm = new HashMap<>(); String sql = "select * from tb_books"; try { conn = DataSourceUtil.initConn(); stm = conn.createStatement(); rs = stm.executeQuery(sql); while (rs.next()) { Book book = new Book(); book.setId(rs.getInt("id")); book.setName(rs.getString("name")); book.setPrice(rs.getDouble("price")); book.setBookCount(rs.getInt("bookCount")); book.setAuthor(rs.getString("author")); hm.put(rs.getInt("id") + "", book); } rs.close(); } catch (Exception e) { e.printStackTrace(); } finally { DataSourceUtil.closeConn(); } return hm; } //插入一本图书信息 public void insertRecord(Book book, String sql) { try { conn = DataSourceUtil.initConn(); ps = conn.prepareStatement(sql); ps.setString(1, book.getName()); ps.setDouble(2, book.getPrice()); ps.setInt(3, book.getBookCount()); ps.setString(4, book.getAuthor()); int insertCount = ps.executeUpdate(); if (insertCount != 0) { System.out.println("插入" + insertCount + "条数据"); } else { System.out.println("插入失败！"); } } catch (Exception e) { e.printStackTrace(); } finally { if (ps != null) { try { ps.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } DataSourceUtil.closeConn(); } } //回收Statement资源 private static void closeStatement(Statement statement) { try { if (null != statement) { statement.close(); } } catch (SQLException e) { e.printStackTrace(); } } //执行一条sql语句 public void updateAndDelete(String sql) { try { conn = DataSourceUtil.initConn(); stm = conn.createStatement(); int num = stm.executeUpdate(sql); if (num == 1) { System.out.println("一条记录删除/更新成功！"); } else { System.out.println("一条记录删除/更新失败！"); } } catch (Exception e) { e.printStackTrace(); } finally { closeStatement(stm); DataSourceUtil.closeConn(); } } //删除指定id的图书 public void deleteId(String id) { try { conn = DataSourceUtil.initConn(); String sql = "delete from tb_books where id=?"; ps = conn.prepareStatement(sql); ps.setString(1, id); int insertCount = ps.executeUpdate(); if (insertCount != 0) { System.out.println("删除" + insertCount + "条数据"); } else { System.out.println("删除失败！"); } } catch (Exception e) { e.printStackTrace(); }finally { if (ps != null) { try { ps.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } DataSourceUtil.closeConn(); } } }