java退票系统写dao层
时间: 2023-11-18 07:11:58 浏览: 32
好的,针对Java退票系统的DAO层,一般需要包含以下几个主要的功能:
1. 查询订单信息:根据订单号或者用户ID等信息查询相关订单信息
2. 更新订单状态:更新订单状态,包括订单的支付状态、退票状态等
3. 插入订单信息:插入新的订单信息,包括订单号、用户ID、订单金额等
4. 删除订单信息:删除指定订单号的订单信息
下面是一个简单的DAO层实现,以订单为例:
```
public class OrderDAO {
// 数据库连接池
private DataSource dataSource;
public OrderDAO(DataSource dataSource) {
this.dataSource = dataSource;
}
// 查询订单信息
public Order findOrderById(int orderId) throws SQLException {
try (Connection conn = dataSource.getConnection()) {
String sql = "SELECT * FROM orders WHERE order_id = ?";
PreparedStatement stmt = conn.prepareStatement(sql);
stmt.setInt(1, orderId);
ResultSet rs = stmt.executeQuery();
if (rs.next()) {
return new Order(rs.getInt("order_id"), rs.getInt("user_id"), rs.getDouble("amount"), rs.getString("status"));
} else {
return null;
}
}
}
// 更新订单状态
public void updateOrderStatus(int orderId, String status) throws SQLException {
try (Connection conn = dataSource.getConnection()) {
String sql = "UPDATE orders SET status = ? WHERE order_id = ?";
PreparedStatement stmt = conn.prepareStatement(sql);
stmt.setString(1, status);
stmt.setInt(2, orderId);
stmt.executeUpdate();
}
}
// 插入订单信息
public void insertOrder(Order order) throws SQLException {
try (Connection conn = dataSource.getConnection()) {
String sql = "INSERT INTO orders (order_id, user_id, amount, status) VALUES (?, ?, ?, ?)";
PreparedStatement stmt = conn.prepareStatement(sql);
stmt.setInt(1, order.getOrderId());
stmt.setInt(2, order.getUserId());
stmt.setDouble(3, order.getAmount());
stmt.setString(4, order.getStatus());
stmt.executeUpdate();
}
}
// 删除订单信息
public void deleteOrder(int orderId) throws SQLException {
try (Connection conn = dataSource.getConnection()) {
String sql = "DELETE FROM orders WHERE order_id = ?";
PreparedStatement stmt = conn.prepareStatement(sql);
stmt.setInt(1, orderId);
stmt.executeUpdate();
}
}
}
```
这里使用了JDBC来进行数据库操作,其中需要传入一个DataSource对象,用于获取数据库连接。在查询、更新、插入和删除订单信息时,都要使用PreparedStatement对象来执行具体的SQL语句,同时注意使用try-with-resources语句来自动关闭数据库连接和PreparedStatement对象,以免造成资源泄漏。