针对JPA的活动记录模式：ActiveJPA
jopen
11年前
ActiveJPA基于JPA，提供了Martin Fowler所提出的活动记录模式（Active Record pattern）的Java实现。借助于ActiveJPA，模型本身会作为DAO并与数据库交互，这样就不需要额外的代码作为数据访问层了。
ActiveJPA使用到了JPA规范，因此所有JPA的ORM实现（Hibernate、EclipseLink、OpenJPA等）都可以与ActiveJPA协同使用。
示例代码：
// Get order by id Order order = Order.findById(12345L); // Get all orders for a customer that are shipped List<Order> orders = Order.where("customer_email", "dummyemail@dummy.com", "status", "shipped"); // Get all orders for the product category 'books' and paginate it Filter filter = new Filter(); filter.setPageNo(1); filter.setPerPage(25); filter.addCondition(new Condition("orderItems.product.category", Operator.eq, "books"); List<Order> orders = Order.where(filter); // Count of orders matching the filter Long count = Order.count(filter); // Get the first order matching the filter Long count = Order.first("customer_email", "dummyemail@dummy.com", "status", "shipped"); // Get the unique order matching the conditions Long count = Order.one("customer_email", "dummyemail@dummy.com", "status", "shipped"); // Dump everything List<Order> orders = Order.all(); // Delete all orders matching the filter Long count = Order.deleteAll(filter); // Check if order exists with the given identifier boolean exists = Order.exists(1234L); // Save order order.setBillingAmount(1000.0); order.persist(); // Delete order order.delete(); // Update attributes Map<String, Object> attributes = new HashMap<String, Object>(); attributes.put("billingAmount", 1000.0); order.updateAttributes(attributes); // Find order item by id within an order order.collections("order_items").findById(123L); // Search order items by filter with an order order.collections("order_items").findById(filter); .... ....