ejbload

How does an entity bean synchronize its in-memory state with the database when the container loads data for a specific entity? How does the bean know which database row to load?

ejbLoad() is a container callback that loads entity state from the database into the bean instance. In BMP, the bean must call getPrimaryKey() to determine which record to load, then execute a SELECT query.

1. Container calls ejbLoad() on the bean instance
2. Bean calls ctx.getPrimaryKey() to get the current entity’s ID
3. Bean acquires JDBC connection
4. Bean executes SELECT query using the primary key
5. Bean populates its fields from the ResultSet

• Called when container assigns a data instance to a bean
• Called after ejbActivate() or at the start of a transaction
• In BMP: developer writes the SELECT logic
• In CMP: container auto-generates the SELECT
• Must call getPrimaryKey() to know which data to load

• Built from: Entity Bean, getPrimaryKey(), Entity Context
• Builds into: ejbStore() (opposite operation)
• Related: JDBC, ejbActivate()

• Not called on every method—only when loading from DB is needed
• Called BEFORE business methods in the ready state
• Don’t confuse with ejbActivate() which acquires resources, not data