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6.6.5.0: EJB module properties >
6.6.5.0.3: Assembly properties for method extensions
6.6.5.0.3: Assembly properties for method extensions
- Method type
- Specifies the type of the enterprise bean method. Valid values are
Home methods, Remote methods, and All methods.
- Name
- Specifies the name of an enterprise bean method, or the asterisk character
(*) . The asterisk is used to denote all the methods of the specified
interface--for example, all methods in the remote interface.
- Parameters
- Contains a list of fully qualified Java type names of the method
parameters. Used to identify a single method among multiple methods
with an overloaded method name.
- Isolation level attributes
- The transaction isolation level determines how isolated one transaction is
from another. This property can be set for individual methods in an
enterprise bean or for all methods in the enterprise bean. An asterisk
is used to indicate all methods in the bean. However, within a
transactional context, the isolation level associated with the first method
invocation becomes the required isolation level for all methods invoked within
that transaction. If a method is invoked with a different isolation
level from that of the first method, the
java.rmi.RemoteException exception is thrown.
- Isolation level
- Specifies the level of transactional isolation. The valid values
are as follows:
- Serializable. This level prohibits the following types of
reads:
- Dirty reads, where a transaction reads a database row containing
uncommitted changes from a second transaction.
- Nonrepeatable reads, where one transaction reads a row, a second
transaction changes the same row, and the first transaction rereads the row
and gets a different value.
- Phantom reads, where one transaction reads all rows that satisfy an SQL
WHERE condition, a second transaction inserts a row that also satisfies the
WHERE condition, and the first transaction applies the same WHERE condition
and gets the row inserted by the second transaction.
- Repeatable read. This level prohibits dirty reads and nonrepeatable
reads, but it allows phantom reads.
- Read committed. This level prohibits dirty reads, but allows
nonrepeatable reads and phantom reads.
- Read uncommitted. This level allows dirty reads, nonrepeatable
reads, and phantom reads.
The container uses the transaction isolation level attribute as
follows:
- Session beans and entity beans with bean-managed persistence
(BMP)--For each database connection used by the bean, the container sets
the transaction isolation level at the start of each transaction unless the
bean explicitly sets the isolation level on the connection.
- Entity beans with container-managed persistence (CMP)--The container
generates database access code that implements the specified isolation
level.
- Security Identity
- Specifies that a principal's credential properties are to be handled
as indicated in the Run-As mode property. Checking this box makes the
Run-as Mode properties editable.
- Description
- Contains text describing or commenting on the security
instructions.
- Run-As Mode
- Credential information is used by the security service to determine the
permissions that a principal has on various resources. At appropriate
points, the security service determines whether the principal is authorized to
use a particular resource based on the principal's permissions. If
the method invocation is authorized, the security service does the following
with the principal's credential properties based on the value of the
Run-as Mode property of the enterprise bean:
- Use Identity of Caller -- the security service makes no changes to
the principal's credential properties.
- Use Identity of EJB Server -- the security service alters the
principals credential properties to match the credential properties associated
with the EJB server.
- Use Identity Assigned to Specified Role -- A principal that has been
assigned to the specified security role is used for the execution of the
bean's methods. This association is part of the application
binding where the role is associated with a user ID and password of a user who
is granted that role.
- Role Name
- Specifies the name of a security role. If the Use Identity Assigned
to Specified Role button is selected, a principal that has been granted this
role will be used.
- Description
- Contains a description of the security role.
- Access Intent - Intent type
- Specifies whether the method is a read-only method or whether the method
can update data (or invoke other methods that can update data, in the same
transaction). The legal values are read or update (read/write).
- Finder descriptor - User
- Specifies that the user has provided a finder helper class in the entity
bean's home interface. The class contains specialized finder
methods.
- Finder descriptor - EJB QL
-
Describes the semantics of a finder method using the EJB QL (Enterprise
JavaBeans query language). EJB QL is a declarative, SQL-like language
intended to be compiled to the target language of the persistent data store
used by a persistence manager. The language is independent of the
bean's mapping to a relational datastore and is therefore
portable. The EJB query specifies a search based on the persistent
attributes and relationships of the bean. An EJB query contains a
SELECT clause (optional), a FROM clause (required), a WHERE clause (optional),
and an ORDER BY clause (optional). The SELECT clause specifies the EJB
objects to return. The FROM clause specifies the collections of objects
to which the query is to be applied. The WHERE clause contains search
predicates over the collections. The ORDER BY clause specifies the
ordering of the resulting collection.
- Finder descriptor - Where clause
-
Describes the semantics of the finder method using an SQL WHERE
clause. This clause restricts the results that are returned by the
query.
For information on restrictions, see the documentation for
Deployment Tool for Enterprise JavaBeans.
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