Network Deployment (Distributed operating systems), v8.0 > Develop and deploying applications > Develop EJB applications > Assembling applications that use the Java Persistence API > Use JPA access intent


Specify TaskName in a JPA persistence unit

Specifying a TaskName in Java Persistence API (JPA) persistence unit

A TaskName is defined in the persistence.xml file using the wsjpa.AccessIntent property name in a persistence unit. The property value is a list of TaskNames, entity types and access intent definitions. The following example shows the contents of the wsjpa.AccessIntent property name in a persistence unit.

<property name  = "wsjpa.AccessIntent"
         value = "Tasks='
<taskName> {
<entityName> (
<isolationLockValue> ) } ' "/>                          A            A              A                    | | |
                         |            |              +--------- , --------+ | |
                         |            +----------------- , -----------------+ |
                         +----------------------- , --------------------------+
  Tasks

      ::=
<task> [ ','
<task> ]*


<task>                       ::=
<taskName> '{'
<entity> [ ','
<entity> ]* '}'


<entity>                     ::=
<entityName> '('
<isolationLockValues> ')'


<taskName>                   ::=
<fully_qualified_identifier>

<entityName>                 ::=
<fully_qualified_identifier>

<fully_qualified_identifier> ::=
<identifier> [ '.'
<identifier> ]*


<identifier>                 ::=
<idStartCharacter> [
<idCharacter> ]*


<idStartCharacter>           ::= Character.isJavaIdentifierStart | '?' | '*'


<idStartCharacter>           ::= Character.isJavaIdentifierPart  | '?' | '*'


<isolationLockValues>        ::=
<isolationLockValue> [ ','
<isolationLockValue> ]


<isolationLockValue>         ::=
<isolation> |
<readLock>

<isolation>                  ::= "isolation" '='
<isolationValue>

<readLock>                   ::= "readlock" '='
<readlockValue>

<isolationValue>             ::= "read-uncommitted"|"read-committed"|"repeatable-read"|"serializable"


<readlockValue>              ::= "read" | "write"


Before setting the TaskName in a persistence unit, keep the following in mind:

The following code example shows how to specify a TaskName in JPA persistence unit.

package my.company;

@Remote
class Ejb1 {
    // assumer no tx from the caller
    @TransactionAttribute(Requires)
    public void caller_Method1() {

        // an implicit new transaction begins
        // TaskName "my.company.Ejb1.caller_Method1" set on TSR

        ejb1.callee_Method?();
    }

    @TransactionAttribute(RequiredNew)
    public void callee_Method2() {

        // an implicit new transaction begins i.e. TxRequiredNew.
        // TaskName "my.company.Ejb1.callee_Method2" set on TSR
    }

    @TransactionAttribute(Requires)
    public void callee_Method3() {

        // In caller's transaction, hence TaskName remains
        //     "my.company.Ejb1.caller_Method1"
    }

    @TransactionAttribute(NotSupported)
    public void callee_LocalTx () {

        // Unspecified transaction, a new local transaction implicitly started.
        // TaskName "my.company.Ejb1.callee_LocalTx" set on TSR
    }

}

Since a wild card can be used to specify TaskName and entity type, multiple specification matches may occur at runtime. The order defined in the wsjpa.AccessIntent property will be used to search for task names and entity types.

<properties>
<property name="wsjpa.AccessIntent" value="Tasks="
        *.Task1 { *.Employee1 ( isolation=read-uncommitted
        ),

 *.Employee? ( isolation=repeatable-read,  readlock=write ),
        },
*       { *.Employee3 ( isolation=serializable,     readlock=write ) },       '" />
</properties>

Use JPA access intent
Set a TaskName using TaskNameAccessor API

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