What is the difference between containers managed persistence and bean-managed persistence?

The main difference between bean-managed and container-managed persistent beans is defined by who manages the persistence of the entity bean’s data. You are required to implement the persistence management within the ejbStore and ejbLoad EntityBean methods. If it does not, the data can be lost.

What is bean-managed persistence?

Bean-Managed Persistence (BMP) occurs when the entity object manages its own persistence. The enterprise bean developer must implement persistence operations (e.g., JDBC, JDO, or SQLJ) directly in the enterprise bean class methods.

What is container-managed bean?

In an enterprise bean with container-managed transaction demarcation, the EJB container sets the boundaries of the transactions. Nested or multiple transactions are not allowed within a method. Container-managed transactions do not require all methods to be associated with transactions.

What is CMP bean?

A container-managed persistence (CMP) bean is an entity bean for which the container handles the interactions between the enterprise bean and the data source. The container is responsible for synchronization of instance fields with the persistent store.

What is CMP and BMP in EJB?

CMP, or Container Managed Persistence, is known to be the simplest for bean developers to create, and is known to be the most complicated for the EJB servers to support. BMP, or Bean Managed Persistence, is known to manage synchronizing its state with databases, as engaged by the container.

What is CMP in j2ee?

The EJB 2.0 specification expanded CMP to allow multiple entity beans to have relationships among themselves. This is referred to as Container-Managed Relationships (CMR). The container manages the relationships and the referential integrity of the relationships.

How would you check the condition of the current transaction in a bean managed transaction?

An enterprise bean with bean-managed transaction demarcation can obtain the status of a transaction by using the getStatus() method of the javax. transaction. UserTransaction interface. An enterprise bean with bean-managed transaction demarcation can rollback a transaction using the rollback() method of the javax.

What is a container managed transaction?

Container managed transactions are considered the place where the container (JEE Server) controls the boundaries of the transactions, when to begin, when to commit or to rollback.

What is Bean-managed transaction in EJB?

In bean-managed transaction demarcation, the code in the session or message-driven bean explicitly marks the boundaries of the transaction. When coding an application-managed transaction for session or message-driven beans, you must decide whether to use Java Database Connectivity or JTA transactions.

What is Java CMP?

What is the difference between session bean and entity bean?

There are two types of EJBs: session beans and entity beans. An easy way to think of the difference is that a session bean implements one or more business tasks, while an entity bean is a complex business entity. Your entity bean can manage multiple dependent persistent objects in performing its necessary tasks.

What is the difference between bean-managed and Container-Managed Persistence?

CMP Components Unlike bean-managed persistence, container-managed persistence does not require you to write database access calls in the methods of the entity bean class.

How do I access persistent data in a container?

Because persistence is handled by the container at runtime, you must specify in the deployment descriptor those persistence fields and relationships for which the container must handle data access. You access persistent data using the accessor methods that are defined for the abstract persistence schema.

What is a concrete bean class?

The concrete bean class, generated by the container-managed persistence implementation. This class inherits from the abstract bean class and uses information from the deployment descriptor. Accessor (read) and mutator (write) methods in the bean class are implemented here to the concrete state class.

What is a container-managed relationship (CMR)?

A container-managed relationship(CMR) between fields in a pair of classes allows operations on one side of the relationship to affect the other side. At runtime, if a field in one instance is modified to refer to another instance, the referred instance will have its relationship field modified to reflect the change in relationship.