vo, dto, dao transfer in java
O is the mapping to the table in the database, one table corresponds to one VO DAO uses VO to access the real table, and all operations on the database are completed in DAO BO is the business layer, doing Logically processed VO, PO, BO, QO, DAO, POJO, O/R Mapping is the abbreviation of Object Relational Mapping. In layman’s terms, it means binding objects to relational databases and using objects to represent relational data. In the world of O/R Mapping, there are two basic and important things that need to be understood, namely VO and PO. VO, Value Object, PO, persistent objects (Persisent Object), they are composed of a set of properties and their get and set methods. Structurally, there is nothing different about them. But it is completely different in its meaning and essence. 1. VO is created using the new keyword and recycled by GC. PO is created when new data is added to the database and deleted when data in the database is deleted. And it can only survive in one database connection and will be destroyed when the connection is disconnected. 2. VO is a value object. To be precise, it is a business object. It…
An introduction to several objects in Java (PO, DO, DTO, DAO, POJO)
PO PO is apersistant object—a persistent object. The concept that appears during O/R mapping ，If there is no O/R mapping，this concept does not exist. Usually corresponds to the data model (database), and itself also has some business logic processing. It can be thought of as a Java object that maps to a table in the database. The simplest PO is a collection corresponding to a record in a certain table in the database – multiple records can use PO. The PO should not contain any operations on the database. DO DO is Domain Object—Domain Object is a tangible object abstracted from the real world or intangible business entity. Generally corresponds to the table structure in the data. TO TO is Transfer Object—data transfer object with different ties (relationships) in the application Objects transferred between DTO DTO is the concept of Data Transfer Object—Data Transfer Object The design pattern derived from J2EE’s original purpose is to provide coarse-grained data entities for EJB distributed applications to reduce the number of distributed calls, thereby improving the performance and reducing the cost of distributed calls. Network load “but here” I generally refer to the data transfer objects between the presentation layer and the service…
Concepts of PO, BO, VO, DTO, POJO, DAO in Java and their functions and project example diagram (translated)
PO (bean, entity, etc. naming): Persistant Object, the display status of records in the database table in the java object The most vivid understanding is that a PO is a record in the database. The advantage is that a record can be processed as an object and can be easily converted to other objects. BO (naming of service, manager, business, etc.): Business Object The main function is to encapsulate business logic as an object. This object can contain one or more other objects. Image is described as the form and action of an object. Of course, it also involves some forms and actions of other objects. For example, when dealing with a person’s business logic, there are behaviors such as sleeping, eating, working, going to work, etc. There are also behaviors that may lead to relationships with others. When dealing with business logic in this way, we can deal with BO. VO (from is also written this way): Value Object Mainly reflected in the object of the view, for a WEB The page encapsulates the properties of the entire page into an object. Then use a VO object to transmit and exchange between the control layer and the view layer.…
Java data object use: PO, DO, TO, DTO, VO, BO, DAO, POJO concept explanation and use
class=”markdown_views prism-atom-one-dark”> PO: Persistent Object Persistent Object The display state of the records in the database table in the java object. The most vivid understanding is that a PO is a record in the database. A record can be treated as an object, and it can also be easily converted to other objects. If there is a piece of data in the database, a simple class is now given an instance of this data, then the existing state of this simple class is PO. (generally/temporarily not used) DO:Domain Object Domain Object Used to receive the entity corresponding to the database, it is an abstract data state, between the database and business logic. Generally, it is used when the Service accesses the database to receive data. Generally placed under the entity/domain package. (Common) TO:Transfer Object Data Transfer Object An object that is transferred between different relationships in the application. (generally/temporarily not used) DTO: Data Tranfer Object Data Transfer Object This concept comes from the J2EE design pattern, which is a method of transferring data between design patterns software application system. The data transferred by the data is generally the data retrieved by the data access object from the database. Generally refers…
