Articles & Tutorial for SCBCD certification
All articles for SCBCD certification
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Describe the life cycle of a message-driven bean.
in SCBCD
The life cycle of a message-driven bean has two states, namely the 'does not exist' and 'pooled' state. A message-driven bean does not maintain any client specific state. It does not have the home and component interfaces. The following image shows the life cycle of a message-driven bean:...
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Describe the life cycle of a message-driven bean.
in SCBCD
The life cycle of a message-driven bean has two states, namely 'does not exist' and 'method-ready pool'. A message-driven bean does not maintain any client specific state. The container is responsible for maintaining the life cycle of a message-driven bean. It provides services such as...
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Describe the life cycle of a stateful session bean.
in SCBCD
The life cycle of a stateful session bean is shown in the following image:
A stateful session bean can have three states during its life as follows: Does not exist
Method ready
Passivated A client invokes the create() method of the stateful session bean. As a result, the container...
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Describe the life cycle of a stateful session bean.
in SCBCD
The life cycle of a stateful session bean is shown in the following image:
A stateful session bean can have three states during its life as follows: Does not exist
Method ready
Passivated A stateful session bean must be annotated with the @stateful annotation or denoted in the...
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Describe the life cycle of a stateless session bean.
in SCBCD
A stateless session bean does not maintain any client specific information. It has only two states in its life cycle as shown below:
Does not exist
Method ready The container creates instances of a stateless session bean and keeps them in a pool of instances. When there is a method...
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Describe the life cycle of a stateless session bean.
in SCBCD
A stateless session bean does not maintain any client specific information. It has only two states in its life cycle as shown below:
Does not exist
Method ready The container creates instances of a stateless session bean and keeps them in a pool of instances. When there is a method...
continue reading "Describe the life cycle of a stateless session bean." »
Describe the life cycle of an entity bean.
in SCBCD
The life cycle of an entity bean is as shown in the following image:
An entity bean can have three states during its life as follows:
Does not exist
Pooled Method ready In the does not exist state, the bean instance has not yet been created. To start an entity bean's life cycle,...
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Differences between EJB 2.1 and EJB 3.0
in SCBCD
The Enterprise JavaBeans 3.0 specification is intended to improve the EJB architecture by reducing its complexity from the developer's point of view. There are many differences between the 2.1 and 3.0 versions. The important differences between the two versions are as follows:
EJB 2.1...
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EJB programming restrictions
in SCBCD
An enterprise bean works best when it follows the EJB programming restrictions. A bean provider must follow these to ensure that the enterprise bean is portable and can be deployed in any compliant EJB 2.0 container. If a bean class does not follow these restrictions, it will still work. However,...
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EJB Transaction
in SCBCD
A transaction is a unit of work that consists of a group of activities performed as a unit such that either all or none of them succeed. An example of where transactions could take place is an online bookstore. In an online bookstore, the purchasing of books involves the following steps:
A...
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