Understanding of PO, VO, BO, POJO, DAO, DTO, TO, QO, Bean, conn in java
O/R Mapping is Object Relational Abbreviation for Mapping (object-relational mapping). In layman’s terms, it means binding objects to relational databases and using objects to represent relational data. in O/R In the world of Mapping, there are two basic and important things that need to be understood, namely VO and PO. VO, Value Object, PO, persistent object (Persisent Object), which 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 lives in the business layer and is used by business logic. The purpose of its existence is to provide a place for data to live. PO is stateful, and each attribute represents its current state. It is an object representation of physical data. Using it, we…
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.…
Description of several objects in Java development (PO, VO, DTO, BO, POJO, DAO, SAO, etc.)
1. PO: (persistant object), persistent object can be seen as a java object that maps to a table in the database. Using Hibernate to generate PO is a good choice. 2. VO: (value object), value object is usually used for data transfer between business layers. Like PO, it only contains data. But it should be an abstracted business object, which may or may not correspond to a table, depending on the needs of the business. PO can only be used in the data layer, and VO is used in business logic layer and presentation layer. Each layer operates its own data objects, which reduces the coupling between layers and facilitates future system maintenance and expansion. 3. DAO: (Data Access Objects), data access object interfaceDAO is the Data Access Object data access interface, data access: as the name suggests Just deal with the database. Sandwiched between business logic and database resources. J2EE developers use the Data Access Object (DAO) design pattern to separate the underlying data access logic from the high-level business logic. Implementing the DAO pattern can focus more on writing data access code. The DAO pattern is one of the standard J2EE design patterns. Developers use this pattern to…
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’s (PO, VO, TO, BO, DAO, POJO) explanation
Recently I am writing an interface for Android, in which the server data needs to define a VO (Value Object) object for encapsulation and transmission The concepts of VO, PO, BO, QO, DAO and POJO are still relatively vague, so I will record them here: 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. PO (persistant object) persistent object The concept that appears when o/r is mapped. If there is no o/r Mapping, no such concept exists anymore. Usually corresponds to the data model (database ), which itself also handles some business logic. It can be seen as a java object that maps to a table in the database. The simplest PO corresponds to a record in a table in the database. Multiple records can use a collection of PO . PO should not contain any operations on the database. VO(value object) Value object Usually used for data transfer between business layers, and PO also only contains data. But it should…
1.Entity classes Entity, Bo, Vo, Po, Dto, Pojo, Dao in java
Entity The most commonly used entity class basically corresponds to the data table one-to-one – one entity and one table. Bo (business object) means business object. Bo is to encapsulate business logic into an object. Note that it is logic. Business logic. This object can include one or Multiple other objects. Perform business operations by calling the Dao method – combined with Po or Vo. Image is described as the form and action of an object – of course there are also some forms and actions related to other objects. For example, when dealing with a person’s business logic, the person will sleep, eat, work, go to work, etc. There may also be behaviors of having relations with others. When dealing with such business logic, we can deal with BO. For another example, the policyholder is a Po, the insured is a Po, the insurance type information is also a Po, etc. Their combination is the Bo of a policy. Vo (value object) represents the meaning of value object – usually used for data transfer between business layers – created by new – recycled by GC. Mainly reflected in the object of the view – for a WEB page, the…
Examples of java business objects_PO, BO, VO, DTO, POJO, DAO concepts and their functions in Java and project example diagram (translated)…
PO (bean, entity, etc. naming)： Persistant Object persistent object，The display status of the records in the database table in the java object Most The visual understanding is that a PO is a record in the database. The advantage is that a record can be treated as an object and can be easily converted to other objects. BO (named as service, manager, business, etc.)： Business Object The main function is to encapsulate business logic into 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, handling a person’s business logic – 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 also has this way of writing) ： Value Object Mainly reflected in the object of the view，For a WEB page Encapsulate 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. DTO (the processed…
javabo object_Explanation of the concepts of DO, PO, BO, DTO, VO and other objects in Java
1. Description of each object 1.1 PO (persistant object) persistent object * Used to represent a record in the database, without any behavior method； * Comply with Java Bean specifications ，Only have getter/setter methods; * A record can be processed as an object，It can be easily converted into other objects. 1.2 DAO (Data Access Object) Data Access Object * Responsible for persistence layer operations ，Usually used in conjunction with PO; * Includes various A database operation method that provides database CRUD operations for the business layer; 1.3 DO (Domain Object) domain object * A tangible or intangible business abstracted from the real world entity. 1.4 BO (business object) Business object * Encapsulates business logic into an object，encapsulates calls to DAO, RPC, etc.; * Can contain one or more other objects – such as a resume BO, which contains PO/DO objects such as educational experience, work experience, social relations, etc. * Can perform PO/DO and VO/DTO Conversion between; 1.5 DTO (Data Transfer Object) data transfer object * Represents a data transfer object; * Usually used for different services or Data transmission between different layers of the service; * Similar in concept to VO，The difference lies in the design concept，It is mainly…
JavaBean, bean, POJO, PO, DTO, VO, BO, EJB, EntityBean
What is JavaBean, bean? What is POJO, PO, DTO, VO, BO? What is EJB, EntityBean？ Preface： We often encounter these conceptual problems in Java development. Some of them may be confused and some may not understand them well. I spent a lot of time to straighten them out. these concepts. However, some concepts are not used in actual development. “Maybe the understanding is not accurate enough” and can only be corrected in the future. 1. What is POJO? MacKenzie put it forward in a speech in 2000. According to Martin Fowler’s explanation, it is “Plain Old Java Object” – literally translated as “pure old-fashioned Java object” – but everyone uses “simple java object” to refer to it. it. The intrinsic meaning of POJO refers to “those Java objects that do not inherit any class or implement any interface” and have not been invaded by other frameworks. Let’s give a definition first: POJO is a simple, ordinary Java object，it contains business logic processing or persistence logic, etc.，but it is not a JavaBean , EntityBean, etc. “do not have any special role” and do not inherit or implement any other Java framework classes or interfaces. Can contain similar JavaBean properties and setter…
What do VO, PO, BO, QO, DAO, POJO mean in Java?
What do VO, PO, BO, DAO, POJO mean in Java I recently encountered VO in a project, my God. . . Then let’s learn and remember together First of all, a brief explanation: O/R Mapping is the abbreviation of Object Relational Mapping (Object relational mapping). To put it simply, it is to bind objects to relational databases and use objects to represent relational data. Java WEBWe need to be more proficient in using the three-tier architecture VO: Value Object Created with the new keyword, GC recycling is usually used for data transfer between business layers. It is generally an abstracted business object, which may or may not correspond to a data table. In the web layer, corresponding to a web page or swt interface, a VO object is used to correspond to the value of an interface. PO: Persistant Object Attributes correspond to fields in the database table one-to-one, and can be regarded as Java objects mapped to tables in the database. Generated by database insert and deleted by database delete. Its life cycle is closely related to the database, but the PO should not contain any operations on the database. The java files are generally the field attributes…
