I am finishing with the summary of:
First, the java bean, is a java component model, he for the use of java classes provide a standard format, the user program management and visualization tools can be automatically entitled to such a standard format with the kind of information and to create and manage these categories.
java bean can make a more object-oriented applications, you can package up the data, the application of business logic and display logic separate, reducing the complexity of the development and maintenance costs!
JavaBean is a JAVA language reusable components. For written JavaBean, type must be concrete and public, and has no constructor parameters. JavaBeans by providing consistency of design patterns in line with the method of public exposure of the internal domain called attributes. As we all know, the attribute name in line with this model, other Java type can be found through the mechanism and operation of self-examination of these JavaBean properties.
From the programming point of view, that is, achieved the most basic way to get the type with the set.
Second, Enterprise Bean, is the Enterprise JavaBean (EJB), is part of J2EE, for the development of the definition of a component-based multi-enterprise application standards. Features include Web services support and the core of development tools (SDK).
J2EE Lane in, Enterprise Java Beans (EJB) Enterprise Java known as Bean, is the core of Java code, respectively conversation Bean (Session Bean), Entity Bean (Entity Bean) and Message-Driven Bean (MessageDriven Bean).
1.Session Bean for the realization of business logic, it can have state, but also can be stateless. Whenever the client requests, the container will select a Session Bean to client service. Session Bean can directly access the database, but more often, it will achieve through the Entity Bean Data Access. This class tends to be used to achieve single-mode case, since each connection needs to use it.
2.Entity Bean is the domain model objects, to achieve the O / R mapping, responsible for records in the database table mapped to the memory of the Entity Object, in fact, create a new Entity Bean object is equivalent to a record, delete an Entity Bean will also be deleted from the database correspond to records, amendments to an Entity Bean, the container will automatically Entity Bean state and database synchronization.
Java Persistence 1.0 specification only of the entity bean as an ordinary Java Object (POJO) to use, and is mapped to the relational database table. And other types of EJB different, entity bean can be assigned, serialization, and like any other POJO as sent through the network.
EJB2.0 in 3.MessageDriven Bean is the introduction of the new enterprise Bean, which is based on JMS message, the client can receive JMS messages sent and then to deal with. MDB is a stateless asynchronous Session Bean, the client having to wait after calling MDB immediately return, MDB asynchronous processing to customer requests. This is suited to the need for asynchronous processing of requests for occasions, such as order processing, so that the client will be able to avoid a long wait until the return of the results of method calls.
Third, Enterprise Bean with the difference between JavaBean
Initially, JavaBean in order to be able to re-use the standard package of software code. Particularly with the help manufacturers develop a comprehensive development environment (IDE) to use the java software components. These include controls such as the Grid, users can drag and drop the components to the development environment. Since then, JavaBean can be extended on a standard java web application components, and JavaBean components of the framework has been extended for the Enterprise Edition of the Bean (EJB).
JavaBean and Server Bean (often referred to as Enterprise JavaBean (EJB)) there are some basic similarities. They are created by a group of characteristics, to perform the specific tasks of the object or component. They have from the current server by the presence of the container's ability to access other features. This makes the behavior bean based on specific tasks and where the environment vary.
JavaBean is a package developed by the use of java.beans, it is the Java 2 Standard Edition part. JavaBean is a machine with an address space of the components run. JavaBean is a component of the process. Enterprise Bean is a package developed by the use of javax.ejb, it is an extension of the standard JDK, Java 2 Enterprise Edition is a part of. Enterprise Bean is in a multi-machine inter-operation of several components of the address space. Enterprise Bean is therefore inter-process components. JavaBean is usually used as a GUI widget, and Distributed Enterprise Bean will be used in a commercial object.
Fourth, POJO a regular Java objects (not the JavaBean, EntityBean, etc.), not to play any special role, nor any Java framework to achieve the specified interface. POJO is a simple, regular Java object, which contains business logic processing or logic, such as persistent, but not a JavaBean, EntityBean and so on, do not have any special role and is not inherited or non-realization of any other Java class or interface framework.
POJO should not we begin to think of the JavaBean, of course, not EJB, it should not be dependent on the framework that succession, or to achieve certain framework or interface. For example: Struts1 of Action and ActionForm of course does not belong to the POJO in Action in Struts2 can not inherit as a result of any interface, so in this case Action is POJO, but Struts2 in Action can not be inherited Class ActionSupport again belong to the POJO. POJO which can contain business logic processing and persistence logic can also include similar with JavaBean properties and to visit the set of attributes and get methods.
Baidu's encyclopedia in the explanation is: a simple Java object (Plain Ordinary Java Objects) is the actual ordinary JavaBeans, use the name of the POJO and EJB in order to avoid confusion with, and referred to more direct. Some attributes and getter setter methods of the class and sometimes can serve as a value object or dto (Data Transform Object) to use. Of course, if you have a simple operation can be attributes, but does not allow business method, we can not carry the type of connection method.
POJO is Plain Ordinary Java Objects acronym for good, but it refers to the Entity Beans do not use ordinary java object, can support the business logic POJO as a category of assistance.
And my understanding is: POJO like the difference between the Entity Bean is only Entity Bean must be mapped to the database, but only for business logic POJO, of course, can also be mapped to the database, that is, the Entity Bean is a POJO exception, of course, they standards are different, and personally think that is based on the Entity Bean's POJO, I do not know right?
References:
http://baike.baidu.com/view/725111.htm
http://www.diybl.com/course/3_program/java/javashl/200845/108451.html
http://www.wang48.com/jishubaodianview/?jsd_id=10969
http://baike.baidu.com/view/209585.htm
http://baike.baidu.com/view/183175.htm
First, the java bean, is a java component model, he for the use of java classes provide a standard format, the user program management and visualization tools can be automatically entitled to such a standard format with the kind of information and to create and manage these categories.
java bean can make a more object-oriented applications, you can package up the data, the application of business logic and display logic separate, reducing the complexity of the development and maintenance costs!
JavaBean is a JAVA language reusable components. For written JavaBean, type must be concrete and public, and has no constructor parameters. JavaBeans by providing consistency of design patterns in line with the method of public exposure of the internal domain called attributes. As we all know, the attribute name in line with this model, other Java type can be found through the mechanism and operation of self-examination of these JavaBean properties.
From the programming point of view, that is, achieved the most basic way to get the type with the set.
Second, Enterprise Bean, is the Enterprise JavaBean (EJB), is part of J2EE, for the development of the definition of a component-based multi-enterprise application standards. Features include Web services support and the core of development tools (SDK).
J2EE Lane in, Enterprise Java Beans (EJB) Enterprise Java known as Bean, is the core of Java code, respectively conversation Bean (Session Bean), Entity Bean (Entity Bean) and Message-Driven Bean (MessageDriven Bean).
1.Session Bean for the realization of business logic, it can have state, but also can be stateless. Whenever the client requests, the container will select a Session Bean to client service. Session Bean can directly access the database, but more often, it will achieve through the Entity Bean Data Access. This class tends to be used to achieve single-mode case, since each connection needs to use it.
2.Entity Bean is the domain model objects, to achieve the O / R mapping, responsible for records in the database table mapped to the memory of the Entity Object, in fact, create a new Entity Bean object is equivalent to a record, delete an Entity Bean will also be deleted from the database correspond to records, amendments to an Entity Bean, the container will automatically Entity Bean state and database synchronization.
Java Persistence 1.0 specification only of the entity bean as an ordinary Java Object (POJO) to use, and is mapped to the relational database table. And other types of EJB different, entity bean can be assigned, serialization, and like any other POJO as sent through the network.
EJB2.0 in 3.MessageDriven Bean is the introduction of the new enterprise Bean, which is based on JMS message, the client can receive JMS messages sent and then to deal with. MDB is a stateless asynchronous Session Bean, the client having to wait after calling MDB immediately return, MDB asynchronous processing to customer requests. This is suited to the need for asynchronous processing of requests for occasions, such as order processing, so that the client will be able to avoid a long wait until the return of the results of method calls.
Third, Enterprise Bean with the difference between JavaBean
Initially, JavaBean in order to be able to re-use the standard package of software code. Particularly with the help manufacturers develop a comprehensive development environment (IDE) to use the java software components. These include controls such as the Grid, users can drag and drop the components to the development environment. Since then, JavaBean can be extended on a standard java web application components, and JavaBean components of the framework has been extended for the Enterprise Edition of the Bean (EJB).
JavaBean and Server Bean (often referred to as Enterprise JavaBean (EJB)) there are some basic similarities. They are created by a group of characteristics, to perform the specific tasks of the object or component. They have from the current server by the presence of the container's ability to access other features. This makes the behavior bean based on specific tasks and where the environment vary.
JavaBean is a package developed by the use of java.beans, it is the Java 2 Standard Edition part. JavaBean is a machine with an address space of the components run. JavaBean is a component of the process. Enterprise Bean is a package developed by the use of javax.ejb, it is an extension of the standard JDK, Java 2 Enterprise Edition is a part of. Enterprise Bean is in a multi-machine inter-operation of several components of the address space. Enterprise Bean is therefore inter-process components. JavaBean is usually used as a GUI widget, and Distributed Enterprise Bean will be used in a commercial object.
Fourth, POJO a regular Java objects (not the JavaBean, EntityBean, etc.), not to play any special role, nor any Java framework to achieve the specified interface. POJO is a simple, regular Java object, which contains business logic processing or logic, such as persistent, but not a JavaBean, EntityBean and so on, do not have any special role and is not inherited or non-realization of any other Java class or interface framework.
POJO should not we begin to think of the JavaBean, of course, not EJB, it should not be dependent on the framework that succession, or to achieve certain framework or interface. For example: Struts1 of Action and ActionForm of course does not belong to the POJO in Action in Struts2 can not inherit as a result of any interface, so in this case Action is POJO, but Struts2 in Action can not be inherited Class ActionSupport again belong to the POJO. POJO which can contain business logic processing and persistence logic can also include similar with JavaBean properties and to visit the set of attributes and get methods.
Baidu's encyclopedia in the explanation is: a simple Java object (Plain Ordinary Java Objects) is the actual ordinary JavaBeans, use the name of the POJO and EJB in order to avoid confusion with, and referred to more direct. Some attributes and getter setter methods of the class and sometimes can serve as a value object or dto (Data Transform Object) to use. Of course, if you have a simple operation can be attributes, but does not allow business method, we can not carry the type of connection method.
POJO is Plain Ordinary Java Objects acronym for good, but it refers to the Entity Beans do not use ordinary java object, can support the business logic POJO as a category of assistance.
And my understanding is: POJO like the difference between the Entity Bean is only Entity Bean must be mapped to the database, but only for business logic POJO, of course, can also be mapped to the database, that is, the Entity Bean is a POJO exception, of course, they standards are different, and personally think that is based on the Entity Bean's POJO, I do not know right?
References:
http://baike.baidu.com/view/725111.htm
http://www.diybl.com/course/3_program/java/javashl/200845/108451.html
http://www.wang48.com/jishubaodianview/?jsd_id=10969
http://baike.baidu.com/view/209585.htm
http://baike.baidu.com/view/183175.htm