WebLogic Server 5.1 EJB Deployment Properties

 

The following sections provide a complete reference for the WebLogic Server 5.1 specific XML deployment properties used in the WebLogic Server EJB 1.1 container and an explanation of how to edit the XML deployment files manually. Use these sections if you need to refer to a list of the deployment descriptors used for EJB 1.1 beans. You can either edit the XML or use the DDConverter to convert the EJB 1.1 deployment descriptors to EJB 2.0 XML that can be used in the EJB 2.0 container.

• Manually Editing XML Deployment Files

• weblogic-ejb-jar.xml Deployment Descriptor File

• weblogic-cmp-rdbms-jar.xml Deployment Descriptor File

Manually Editing XML Deployment Files

To define or make changes to the XML deployment descriptors used in the WebLogic Server EJB 1.1 container you must manually define or edit the XML elements in the following files:

• weblogic ejb.jar

• weblogic.cmp.rdbms.jar

Basic Conventions

To manually edit XML elements:

• Make sure that you use an ASCII text editor that does not reformat the XML or insert additional characters that could invalidate the file

• Use the correct case for file and directory names, even if your operating system ignores the case.

• To use the default value for an optional element, you can either omit the entire element definition or specify a blank value, as in:

  <max-beans-in-cache></max-beans-in-cache>

DOCTYPE Header Information

When editing or creating XML deployment files, it is critical to include the correct DOCTYPE header for each deployment file. In particular, using an incorrect PUBLIC element within the DOCTYPE header can result in parser errors that may be difficult to diagnose. The correct text for the PUBLIC element for each XML deployment file is as follows.

XML File	PUBLIC Element String
ejb-jar.xml	`-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 1.1//EN' `http://www.java.sun.com/j2ee/dtds/ejb-jar_1_1.dtd'
weblogic-ejb-jar.xml	`-//BEA Systems, Inc.//DTD WebLogic 5.1.0 EJB//EN' `http://www.bea.com/servers/wls510/dtd/weblogic-ejb-jar.dtd'
weblogicmp-rdbms -jar.xml	`-//BEA Systems, Inc.//DTD WebLogic 5.1.0 EJB RDBMS Persistence//EN' http://www.bea.com/servers/wls510/dtd/weblogic-rdbms-persistence.dtd

For example, the entire DOCTYPE header for a weblogic-ejb-jar.xml file is as follows:

<!DOCTYPE weblogic-ejb-jar PUBLIC 
'-//BEA Systems, Inc.//DTD WebLogic 5.1.0 EJB//EN' 'http://www.bea.com/servers/wls510/dtd/weblogic-ejb-jar.dtd '>

XML files with incorrect header information may yield error messages similar to the following, when used with a utility that parses the XML (such as ejbc):

SAXException: This document may not have the identifier `identifier_name'

identifier_name generally includes the invalid text from the PUBLIC element.

Document Type Definitions (DTDs) for Validation

The contents and arrangement of elements in your XML files must conform to the Document Type Definition (DTD) for each file you use. WebLogic Server utilities ignore the DTDs embedded within the DOCTYPE header of XML deployment files, and instead use the DTD locations that were installed along with the server. However, the DOCTYPE header information must include a valid URL syntax in order to avoid parser errors.

The following links provide the public DTD locations for XML deployment files used with WebLogic Server:

• ejb-jar.dtd contains the DTD for the standard ejb-jar.xml deployment file, required for all EJBs. This DTD is maintained as part of the JavaSoft EJB 1.1 specification; refer to the JavaSoft specification for information about the elements used in ejb-jar.dtd.

• weblogic-ejb-jar.dtd contains the DTD used for creating weblogic-ejb-jar.xml, which defines EJB properties used for deployment to WebLogic Server. This file is located at http://www.bea.com/servers/wls510/dtd/weblogic-ejb-jar.dtd

• weblogic-rdbms-persistence.dtd contains the DTD that defines container-managed persistence properties for entity EJBs. This DTD is used to create the weblogic-rdbms-persistence.xml file for using WebLogic Server persistence services. Third-party persistence vendors may also create XML deployment files that conform to this DTD. This file is located at http://www.bea.com/servers/wls510/dtd/weblogic-rdbms-persistence.dtd

  Note: Most browsers do not display the contents of files having the .dtd extension. To view the DTD file contents in your browser, save the links as text files and view them with a text editor.

weblogic-ejb-jar.xml Deployment Descriptor File

weblogic-ejb-jar.xml defines EJB deployment properties unique to WebLogic Server. The top level elements in weblogic-ejb-jar.xml are as follows:

• description of the file

• copyright information

• weblogic-enterprise-bean

  • ejb-name

  • caching-descriptor

  • persistence-descriptor

  • clustering-descriptor

  • transaction-descriptor

  • reference-descriptor

  • jndi-name

  • transaction-isolation

• security-role-assignment

Caching Properties

This section describes the weblogic-ejb-jar.xml caching properties.

caching-descriptor

The caching-descriptor stanza affects the number of EJBs in the WebLogic Server cache as well as the length of time before EJBs are passivated or pooled. The entire stanza, as well as each of its elements, is optional. WebLogic Server uses default values where no elements are defined.

The following is a sample caching-descriptor stanza that shows the caching elements described in this section:

<caching-descriptor>

   <

max-beans-in-free-pool>500</max-beans-in-free-pool>

   <

initial-beans-in-free-pool>50</initial-beans-in-free-pool>

   <

max-beans-in-cache>1000</max-beans-in-cache>

   <

idle-timeout-seconds>20</idle-timeout-seconds>

   <

cache-strategy>Read-Write</cache-strategy>

   <

read-timeout-seconds>0</read-timeout-seconds>

</caching-descriptor>

max-beans-in-free-pool

Note: This element is valid only for stateless session EJBs.

WebLogic Server maintains a free pool of EJBs for every stateless session bean class only. This optional element defines the size of the pool. By default, max-beans-in-free-pool has no limit; the maximum number of beans in the free pool is limited only by the available memory. See Initializing and Using EJB Instances in The WebLogic Server EJB Container for more information.

initial-beans-in-free-pool

Note: This element is valid only for stateless session EJBs.

If you specify a value for initial-bean-in-free-pool, WebLogic Server populates the free pool with the specified number of stateless session bean instances at startup. Populating the free pool in this way improves initial response time for the EJB, since initial requests for the bean can be satisfied without generating a new instance.

initial-bean-in-free-pool defaults to 0 if the element is not defined.

max-beans-in-cache

Note: This element is valid only for stateful session EJBs and entity EJBs.

This element specifies the maximum number of objects of this class that are allowed in memory. When max-bean-in-cache is reached, WebLogic Server passivates some EJBs that have not been recently used by a client. max-beans-in-cache also affects when EJBs are removed from the WebLogic Server cache, as described in Removing Stateful Session EJB Instances.

The default value of max-beans-in-cache is 100.

idle-timeout-seconds

idle-timeout-seconds defines the maximum length of time a stateful EJB should remain in the cache. After this time has elapsed, WebLogic Server may remove the bean instance if the number of beans in cache approaches the limit of max-beans-in-cache. See EJB Life Cycle in WebLogic Server for more information.

idle-timeout-seconds defaults to 600 if you do not define the element.

cache-strategy

The cache-strategy element can be one of the following:

• Read-Write

• Read-Only

The default value is Read-Write. See Setting the Entity EJBs to Read-Only for more information.

read-timeout-seconds

The read-timeout-seconds element specifies the number of seconds between ejbLoad() calls on a Read-Only entity bean. By default, read-timeout-seconds is set to 600 seconds. If you set this value to 0, WebLogic Server calls ejbLoad only when the bean is brought into the cache.

Persistence Properties

This section describes the weblogic-ejb-jar.xml persistence properties.

persistence-descriptor

The persistence-descriptor stanza specifies persistence options for entity EJBs. The following shows all elements contained in the persistence-descriptor stanza:

<persistence-descriptor>

   <

is-modified-method-name>. . .</is-modified-method-name>

   <

delay-updates-until-end-of-tx>. . .</delay-updates-until-end-of-tx>

   <

persistence-type>

      <type-identifier>. . .</type-identifier>

      <type-version>. . .</type-version>

      <type-storage>. . .</type-storage>

   </persistence-type>

   <

db-is-shared>. . .</db-is-shared>

   <

stateful-session-persistent-store-dir>

      . . .

   </stateful-session-persistent-store-dir>

   <

persistence-use>. . .</persistence-use>

</persistence-descriptor>

is-modified-method-name

is-modified-method-name specifies a method that WebLogic Server calls when the EJB is stored. The specified method must return a boolean value. If no method is specified, WebLogic Server always assumes that the EJB has been modified and always saves it.

Providing a method and setting it as appropriate can improve performance. However, any errors in the method's return value can cause data inconsistency problems. See Using is-modified-method-name to Limit Calls to ejbStore() for more information.

delay-updates-until-end-of-tx

Set this element to true (the default), to update the persistent store of all beans in a transaction at the completion of the transaction. This generally improves performance by avoiding unnecessary updates. However, it does not preserve the ordering of database updates within a database transaction.

If your datastore uses an isolation level of TRANSACTION_READ_UNCOMMITTED, you may want to allow other database users to view the intermediate results of in-progress transactions. In this case, set delay-updates-until-end-of-tx to false to update the bean's persistent store at the conclusion of each method invoke. See ejbLoad() and ejbStore() Behavior for Entity EJBs for more information.

Note: Setting delay-updates-until-end-of-tx to false does not cause database updates to be "committed" to the database after each method invoke; they are only sent to the database. Updates are committed or rolled back in the database only at the conclusion of the transaction.

persistence-type

A persistence-type defines a persistence service that can be used by an EJB. You can define multiple persistence-type entries in weblogic-ejb-jar.xml for testing with multiple persistence services. Only the persistence type defined in persistence-use is used during deployment.

persistence-type includes several elements that define the properties of a service:

• type-identifier contains text that identifies the specified persistence type. For example, WebLogic Server RDBMS persistence uses the identifier, WebLogic_CMP_RDBMS.

• type-version identifies the version of the specified persistence type.

  Note: The specified version must exactly match the RDBMS persistence version for the WebLogic Server release. Specifying an incorrect version results in the error:

  weblogic.ejb.persistence.PersistenceSetupException: Error initializing the CMP Persistence Type for your bean: No installed Persistence Type matches the signature of (identifier `Weblogic_CMP_RDBMS', version `version_number').

• type-storage defines the full path of the file that stores data for this persistence type. The path must specify the file's location relative to the top level of the EJB's .jar deployment file or deployment directory.

  WebLogic Server RDBMS-based persistence generally uses an XML file named weblogic-cmp-rdbms-jar.xml to store persistence data for a bean. This file is stored in the META-INF subdirectory of the .jar file.

The following shows an example persistence-type stanza with values appropriate for WebLogic Server RDBMS persistence:

<persistence-type>

     <type-identifier>WebLogic_CMP_RDBMS</type-identifier>

     <type-version>5.1.0</type-version>

     <type-storage>META-INF\weblogic-cmp-rdbms-jar.xml</type-storage>

</persistence-type>

db-is-shared

The db-is-shared element applies only to entity beans. When set to true (the default value), WebLogic Server assumes that EJB data could be modified between transactions and reloads data at the beginning of each transaction. When set to false, WebLogic Server assumes that it has exclusive access to the EJB data in the persistent store. See Using db-is-shared to Limit Calls to ejbLoad() for more information.

stateful-session-persistent-store-dir

stateful-session-persistent-store-dir specifies the file system directory where WebLogic Server stores the state of passivated stateful session bean instances.

persistence-use

The persistence-use element is similar to persistence-type, but it defines the persistence service actually used during deployment. persistence-use uses the type-identifier and type-version elements defined in a persistence-type to identify the service.

For example, to actually deploy an EJB using the WebLogic Server RDBMS-based persistence service defined in persistence-type, the persistence-use stanza would resemble:

<persistence-use>

   <type-identifier>WebLogic_CMP_RDBMS</type-identifier>

   <type-version>5.1.0</type-version>

</persistence-use>

Clustering Properties

This section describes the weblogic-ejb-jar.xml clustering properties.

clustering-descriptor

The clustering-descriptor stanza defines the replication properties and behavior for EJBs deployed in a WebLogic Server cluster. The clustering-descriptor stanza and each of its elements are optional, and are not applicable to single-server systems.

The following shows all elements contained in the clustering-descriptor stanza:

<clustering-descriptor>

   <

home-is-clusterable>. . .</home-is-clusterable>

   <

home-load-algorithm>. . .</home-load-algorithm>

   <

home-call-router-class-name>. . .</home-call-router-class-name>

   <

stateless-bean-is-clusterable>. . .</stateless-bean-is-clusterable>

   <

stateless-bean-load-algorithm>. . .</stateless-bean-load-algorithm>

   <

stateless-bean-call-router-class-name>. . .</stateless-bean-call-router-class-name>

   <

stateless-bean-methods-are-idempotent>. . .</stateless-bean-methods-are-idempotent>

</clustering-descriptor>

home-is-clusterable

You can set this element to either true or false. When home-is-clusterable is true, the EJB can be deployed from multiple WebLogic Servers in a cluster. Calls to the home stub are load-balanced between the servers on which this bean is deployed, and if a server hosting the bean is unreachable, the call automatically fails over to another server hosting the bean.

home-load-algorithm

home-load-algorithm specifies the algorithm to use for load balancing between replicas of the EJB home. If this element is not defined, WebLogic Server uses the algorithm specified by the server element, weblogic.cluster.defaultLoadAlgorithm.

You can define home-load-algorithm as one of the following values:

• round-robin: Load balancing is performed in a sequential fashion among the servers hosting the bean.

• random: Replicas of the EJB home are deployed randomly among the servers hosting the bean.

• weight-based: Replicas of the EJB home are deployed on host servers according to the servers' current workload.

home-call-router-class-name

home-call-router-class-name specifies the custom class to use for routing bean method calls. This class must implement weblogic.rmi.extensions.CallRouter(). If specified, an instance of this class is called before each method call. The router class has the opportunity to choose a server to route to based on the method parameters. The class returns either a server name or null, which indicates that the current load algorithm should select the server.

stateless-bean-is-clusterable

This element is similar to home-is-clusterable, but it is applicable only to stateless session EJBs.

stateless-bean-load-algorithm

This element is similar to home-load-algorithm, but it is applicable only to stateless session EJBs.

stateless-bean-call-router-class-name

Thiselement is similar to home-call-router-class-name, but it is applicable only to stateless session EJBs.

stateless-bean-methods-are-idempotent

You can set this element to either true or false. Set stateless-bean-methods-are-idempotent to true only if the bean is written such that repeated calls to the same method with the same arguments has exactly the same effect as a single call. This allows the failover handler to retry a failed call without knowing whether the call actually completed on the failed server. Setting this element to true makes it possible for the bean stub to automatically recover from any failure as long as another server hosting the bean can be reached.

Note: This element is applicable only to stateless session EJBs.

Transaction Properties

This section describes the weblogic-ejb-jar.xml transaction properties.

transaction-descriptor

The transaction-descriptor stanza contains elements that define transaction behavior in WebLogic Server. Currently, this stanza includes only one element:

<transaction-descriptor>

   <

trans-timeout-seconds>20</trans-timeout-seconds>

<transaction-descriptor>

trans-timeout-seconds

The trans-timeout-seconds element specifies the maximum duration for the EJB's container-initiated transactions. If a transaction lasts longer than trans-timeout-seconds, WebLogic Server rolls back the transaction.

If you specify no value for trans-timeout-seconds, container-initiated transactions timeout after five minutes, by default.

EJB References

This section describes the weblogic-ejb-jar.xml EJB references.

reference-descriptor

The reference-descriptor stanza maps references in the ejb-jar.xml file to the JNDI names of actual resource factories and EJBs available in WebLogic Server.

The reference-descriptor stanza contains one or more additional stanzas to define resource factory references and EJB references. The following shows the organization of these elements:

<reference-descriptor>

   <

resource-description>

      <res-ref-name>. . .</res-ref-name>

      <jndi-name>. . .</jndi-name>

   </resource-description>

   <

ejb-reference-description>

      <ejb-ref-name>. . .</ejb-ref-name>

      <jndi-name>. . .</jndi-name>

   </ejb-reference-description>

</reference-descriptor>

resource-description

The following elements define an individual resource-description:

• res-ref-name specifies a resource reference name. This is the reference that the EJB provider places within the ejb-jar.xml deployment file.

• jndi-name specifies the JNDI name of an actual resource factory available in WebLogic Server.

ejb-reference-description

The following elements define an individual ejb-reference-description:

• res-ref-name specifies an EJB reference name. This is the reference that the EJB provider places within the ejb-jar.xml deployment file.

• jndi-name specifies the JNDI name of an actual EJB available in WebLogic Server.

Isolation Level Settings

This section describes the weblogic-ejb-jar.xml isolation level settings.

transaction-isolation

The transaction-isolation stanza specifies the transaction isolation level for EJB methods. The stanza consists of one or more isolation-level elements that apply to a range of EJB methods. For example:

<transaction-isolation>

  <isolation-level>Serializable</isolation-level>

  <method>

    <description>...</description>

    <ejb-name>...</ejb-name>

    <method-intf>...</method-intf>

    <method-name>...</method-name>

    <method-params>...</method-params>

  </method>

</transaction-isolation>

The following sections describe each element in transaction-isolation.

isolation-level

isolation-level defines a valid transaction isolation level to apply to specific EJB methods. The following are possible values for isolation-level:

• TRANSACTION_READ_UNCOMMITTED: The transaction can view uncommitted updates from other transactions.

• TRANSACTION_READ_COMMITTED: The transaction can view only committed updates from other transactions.

• TRANSACTION_REPEATABLE_READ: Once the transaction reads a subset of data, repeated reads of the same data return the same values, even if other transactions have subsequently modified the data.

• TRANSACTION_SERIALIZABLE: Simultaneously executing this transaction multiple times has the same effect as executing the transaction multiple times in a serial fashion.

Refer to your database documentation for more information on the implications and support for different isolation levels.

method

The method stanza defines the EJB methods to which an isolation level applies. method defines a range of methods using the following elements:

• description is an optional element that describes the method.

• ejb-name identifies the EJB to which WebLogic Server applies isolation level properties.

• method-intf is an optional element that indicates whether the specified method(s) reside in the EJB's home or remote interface. The value of this element must be "Home" or "Remote". If you do not specify method-intf, you can apply an isolation to methods in both interfaces.

• method-name specifies either the name of an EJB method or an asterisk (*) to designate all EJB methods.

• method-params is an optional stanza that lists the Java types of each of the method's parameters. The type of each parameter must be listed in order, using individual method-param elements within the method-params stanza.

For example, the following method stanza designates all methods in the "AccountBean" EJB:

<method>

  <ejb-name>AccountBean</ejb-name>

  <method-name>*</method-name>

</method>

The following stanza designates all methods in the remote interface of "AccountBean:"

<method>

  <ejb-name>AccountBean</ejb-name>

  <method-intf>Remote</method-intf>

  <method-name>*</method-name>

</method>

Security Role Assignments

This section describes the weblogic-ejb-jar.xml security role assignments.

security-role-assignment

The security-role-assignment stanza maps application roles in the ejb-jar.xml file to the names of security principals available in WebLogic Server.

security-role-assignment can contain one or more pairs of the following elements:

• role-name is the application role name that the EJB provider placed in the ejb-jar.xml deployment file.

• principal-name specifies the name of an actual WebLogic Server principal.

enable-call-by-reference

By default, EJB methods called from within the same server pass arguments by reference. This increases the performance of method invocation since parameters are not copied.

If you set enable-call-by-reference to false, parameters to EJB methods are copied (pass by value) in accordance with the EJB 1.1 specification. Pass by value is always necessary when the EJB is called remotely (not from within the server).

weblogic-cmp-rdbms-jar.xml Deployment Descriptor File

weblogic-cmp-rdbms-jar.xml defines deployment properties for a single entity EJB that uses WebLogic Server RDBMS-based persistence services. See Persistence Services for more information.

The top-level element of weblogic-cmp-rdbms-jar.xml are as follows:

• description of the file

• copyright information

• weblogic-enterprise-bean stanza

  <weblogic-enterprise-bean>

     <
  
  pool-name>finance_pool</pool-name>

     <
  
  schema-name>FINANCE_APP</schema-name>

     <
  
  table-name>ACCOUNT</table-name>

     <
  
  attribute-map>

        <
  
  object-link>

           <
  
  bean-field>accountID</bean-field>

           <
  
  dbms-column>ACCOUNT_NUMBER</dbms-column>

        </object-link>

        <
  
  object-link>

           <
  
  bean-field>balance</bean-field>

           <
  
  dbms-column>BALANCE</dbms-column>

        </object-link>

     </attribute-map>

     <
  
  finder-list>

        <
  
  finder>

           <
  
  method-name>findBigAccounts</method-name>

           <
  
  method-params>

              <
  
  method-param>double</method-param>

           </method-params>

        <
  
  finder-query><![CDATA[(> balance $0)]]></finder-query>

        <
  
  finder-expression>. . .</finder-expression>

        </finder>

     </finder-list>

  </weblogic-enterprise-bean>

RDBMS Definition Elements

This section describes the weblogic-cmp-rdbms-jar.xml RDBMS definition elements.

pool-name

pool-name specifies name of the WebLogic Server connection pool to use for this EJB's database connectivity. See Using connection pools for more information.

schema-name

schema-name specifies the schema where the source table is located in the database. This element is required only if you want to use a schema that is not the default schema for the user defined in the EJB's connection pool.

Note: This field is case sensitive, although many SQL implementations ignore case.

table-name

table-name specifies the source table in the database. This element is required in all cases.

Note: The user defined in the EJB's connection pool must have read and write privileges to the specified table, though not necessarily schema modification privileges. This field is case sensitive, although many SQL implementations ignore case.

EJB Field-Mapping Elements

This section describes the weblogic-cmp-rdbms-jar.xml EJB field-mapping elements.

attribute-map

The attribute-map stanza links a single field in the EJB instance to a particular column in the database table. The attribute-map must have exactly one entry for each field of an EJB that uses WebLogic Server RDBMS-based persistence.

object-link

Each attribute-map entry consists of an object-link stanza, which represents a link between a column in the database and a field in the EJB instance.

bean-field

bean-field specifies the field in the EJB instance that should be populated from the database. This element is case sensitive and must precisely match the name of the field in the bean instance.

The field referenced in this tag must also have a cmp-field element defined in the ejb-jar.xml file for the bean.

dbms-column

dbms-column specifies the database column to which the EJB field is mapped. This tag is case sensitive, although many databases ignore the case.

Note: WebLogic Server does not support quoted RDBMS keywords as entries to dbms-column. For example, you cannot create an attribute map for column names such as "create" or "select" if those names are reserved in the underlying datastore.

Finder Elements

This section describes the weblogic-cmp-rdbms-jar.xml finder elements.

finder-list

The finder-list stanza defines the set of all finders that are generated to locate sets of beans. See Writing Finders for RDBMS Persistence for more information.

finder-list must contain exactly one entry for each finder method defined in the home interface, except for findByPrimarykey. If an entry is not provided for findByPrimaryKey, one is generated at compilation time.

Note: If you do provide an entry for findByPrimaryKey, WebLogic Server uses that entry without validating it for correctness. In most cases, you should omit an entry for findByPrimaryKey and accept the default, generated method.

finder

The finder stanza describes a finder method defined in the home interface. The elements contained in the finder stanza enable WebLogic Server to identify which method in the home interface is being described, and to perform required database operations.

method-name

method-name defines the name of the finder method in the home interface. This tag must contain the exact name of the method.

method-params

The method-params stanza defines the list of parameters to the finder method being specified in method-name.

Note: WebLogic Server compares this list against the parameter types for the finder method in the EJB's home interface; the order and type for the parameter list must exactly match the order and type defined in the home interface.

method-param

method-param defines the fully-qualified name for the parameter's type. The type name is evaluated into a java.lang.Class object, and the resultant object must precisely match the respective parameter in the EJB's finder method.

You can specify primitive parameters using their primitive names (such as "double" or "int"). If you use a non-primitive data type in a method-param element, you must specify a fully qualified name. For example, use java.sql.Timestamp rather than Timestamp. If you do not use a qualified name, ejbc generates an error message when you compile the deployment unit.

finder-query

finder-query specifies the WebLogic Query Language (WLQL) string that is used to retrieve values from the database for this finder. See Using WebLogic Query Language (WLQL) for more information.

Note: Always define the text of the finder-query value using the XML CDATA attribute. Using CDATA ensures that any special characters in the WLQL string do not cause errors when the finder is compiled.

finder-expression

finder-expression specifies a Java language expression to use as a variable in the database query for this finder.

Note: Future versions of the WebLogic Server EJB container will use the EJB QL query language (as required by the EJB 2.0 specification). EJB QL does not provide support for embedded Java expressions. Therefore, to ensure easier upgrades to future EJB containers, create entity EJB finders without embedding Java expressions in WLQL.