ejb-j2ee-engine.dtd (SAP Library

ejb-j2ee-engine.dtd

Definition

A Document Type Definition (DTD) that describes how you specify additional information about enterprise beans. This information is specified here, because the EJB Specification does not explicitly define the exact element names that should be used. This XML is optional for session and entity beans. However, it is required if your EJB application contains message-driven beans, because it contains information, without which the beans cannot work.

Structure

The ejb-j2ee-engine.dtd defines the following elements:

This graphic is explained in the accompanying text

The usage of each element is explained below:

<!--

The root element of this deployment descriptor. It contains additional information about the enterprise beans in your application.

-->

<!ELEMENT ejb-j2ee-engine (description?, enterprise-beans?, transaction-descriptor?, security-permission?)>

<!--

Description of the contents of this XML.

-->

<!ELEMENT description (#PCDATA)>

<!--

Describes enterprise beans’ deployment specifics.

-->

<!ELEMENT enterprise-beans (enterprise-bean+)>

<!ELEMENT enterprise-bean (ejb-name, jndi-name?, container-size?, ejb-ref*, ejb-local-ref*, resource-ref*, resource-env-ref*, server-component-ref*, run-as-identity-map?, ior-security-config*, (session-props|entity-props|message-props)?)>

<!--

The name of the enterprise bean. It is the same as the ejb-name specified in the ejb-jar.xml file. This name must be unique among the enterprise bean names in the JAR.

-->

<!ELEMENT ejb-name (#PCDATA)>

<!--

An arbitrary JNDI name for the bean.

Caution

We recommend that you do not specify or use this arbitrary JNDI name because the JNDI name that you specify must be unique within all other beans and objects bound in the JNDI namespace of the J2EE Engine, and name conflicts may occur. Also, if you specify a prefix in the arbitrary JNDI name of your bean, this prefix must not coincide with the name of another object bound in the JNDI namespace.

Instead of specifying this arbitrary JNDI name, we recommend that you declare EJB references and use them to access your beans (when the client application is a J2EE application) or you use the default JNDI name of the bean to look up it (when the client application is not a J2EE application). For more information, see Structure link Looking Up Enterprise Beans.

-->

<!ELEMENT jndi-name (#PCDATA)>

<!--

The initial size of the EJB Container when the bean is loaded.

-->

<!ELEMENT container-size (#PCDATA)>

<!--

Caution

Use this element only if the information in the corresponding <ejb-ref> element in the ejb-jar.xml is not sufficient to identify the referenced bean (for example, when there is more than one enterprise bean with the same remote interfaces deployed on the J2EE Engine).

This element additionally defines a remote EJB reference that the referring bean has to another enterprise bean (by specifying the JNDI name of the referenced enterprise bean). This remote EJB reference must be defined first in an <ejb-ref> element in ejb-jar.xml.

Example:

    <ejb-ref>
        <ejb-ref-name>myEJBRef</ejb-ref-name>
        <jndi-name>ReferencedEJBJNDIName</jndi-name>
    </ejb-ref>

-->

<!ELEMENT ejb-ref (ejb-ref-name, jndi-name)>

<!--

The name of the EJB reference as defined in ejb-jar.xml. The value of this element must be the same as the value of the corresponding <ejb-ref-name> element in ejb-jar.xml.

-->

<!ELEMENT ejb-ref-name (#PCDATA)>

<!--

Specifies the JNDI name of the referenced bean.

-->

<!ELEMENT jndi-name (#PCDATA)>

<!--

Caution

Use this element only if the information in the corresponding <ejb-local-ref> element in the ejb-jar.xml is not sufficient to identify the referenced bean (for example, when there is more than one enterprise bean with the same local interfaces deployed on the J2EE Engine).

This element additionally defines a local EJB reference that the referring bean has to another enterprise bean (by specifying the JNDI name of the referenced enterprise bean). This local EJB reference must be defined first in an <ejb-local-ref> element in ejb-jar.xml.
See also Structure link Declaring EJB References.

Example:

    <ejb-local-ref>
        <ejb-ref-name>myEJBLocalRef</ejb-ref-name>
        <jndi-name>ReferencedEJBJNDIName</jndi-name>
    </ejb-local-ref>
-->

<!ELEMENT ejb-local-ref (ejb-ref-name, jndi-name)>

<!--

The name of the EJB reference as defined in ejb-jar.xml. The value of this element must be the same as the value of the corresponding <ejb-ref-name> element in ejb-jar.xml.

-->

<!ELEMENT ejb-ref-name (#PCDATA )>

<!--

Specifies the JNDI name of the referenced bean.

-->

<!ELEMENT jndi-name (#PCDATA)>

<!--

Additionally defines an enterprise bean’s reference to an external resource (by specifying the JNDI name of the referenced resource and/or defining the resource as non-transactional). This reference must be defined first in the ejb-jar.xml.

Example:

    <resource-ref>
        <res-ref-name>myResourceRef</res-ref-name>
        <res-link>ReferencedResourceJNDIName</res-link>
        <non-transactional/>
    </resource-ref>

-->

<!ELEMENT resource-ref (res-ref-name, res-link, non-transactional?)>

<!--

The name of the resource manager connection factory reference as defined in ejb-jar.xml. The value of this element must be the same as the value of the corresponding <res-ref-name> element in ejb-jar.xml.

-->

<!ELEMENT res-ref-name (#PCDATA)>

<!--

Specifies the JNDI name of the referenced resource.

The value of this tag depends on the type of the referenced resource:

● for resources of type javax.sql.DataSource it is either the value of the <data-source-name>, or the value of the <alias> tag you specified in the data-sources.xml descriptor. Or if you have used the data-source-aliases.xml instead, the value of this tag must be the same as the value of the <alias> tag for the corresponding DataSource.

● for resources of type javax.jms.QueueConnectionFactory and javax.jms.TopicConnectionFactory it is either the value of the <factory-name>, or the value of the <alias> tag you specified in the jms-factories.xml descriptor.

● for resources of type javax.resource.cci.ConnectionFactory it is either the value of the <jndi-name> tag, or the value of the <alias> tag you specified in the connector-j2ee-engine.xml descriptor. Or, ifyou have not used the connector-j2ee-engine.xml descriptor at all (since it is not mandatory), the value of this tag is equivalent to the name of the corresponding RAR file (not including the .rar file extension).

-->

<!ELEMENT res-link (#PCDATA)>

<!--

If this element exists, defines the resource as non-transactional. By default the resource is transactional. For more information, see Structure link Connection Handling in Distributed and Local Transactions (in the Development Manual).

-->

<!ELEMENT non-transactional EMPTY>

<!--

Additionally defines an enterprise bean’s reference to an administered object associated with a resource in the bean’s environment (by specifying the JNDI name of the resource environment reference). This reference must be defined first in the ejb-jar.xml.

Example:

    <resource-env-ref>
        <res-env-ref-name>myEnvResourceName</res-env-ref-name>
        <jndi-name>ReferencedEnvResourceJNDIName</jndi-name>
    </resource-env-ref>
-->

<!ELEMENT resource-env-ref (res-env-ref-name, jndi-name)>

<!--

The name of the resource environment reference as defined in ejb-jar.xml. The value of this element must be the same as the value of the corresponding <resource-env-ref-name> element in ejb-jar.xml.

-->

<!ELEMENT res-env-ref-name (#PCDATA)>

<!--

Specifies the JNDI name of the resource environment reference.

The value of this element must be the same as the name of the resource environment entry that you have specified in the <destination-name> element of the jms-destinations.xml descriptor.

-->

<!ELEMENT jndi-name (#PCDATA)>

<!--

Specifies a reference from the EJB application to the J2EE Engine interface or to service objects bound in the JNDI namespace. To be able to look up the specified object, apart from this reference, you must also declare a reference to the corresponding J2EE Engine service or interface in the <reference> element in the application’s application-j2ee-engine.xml.

Example:

    <server-component-ref>
        <description>This element describes an application reference to the myInterface interface</description>
        <name>myInterface</name>
        <type>interface</type>
        <jndi-name>ReferencedInterfaceJNDIName</jndi-name>
    </server-component-ref>
-->

<!ELEMENT server-component-ref (description?, name, type, jndi-name)>

<!--

The name with which the resource will be looked up. This name is relative to the java:comp/env context.

-->

<!ELEMENT name (#PCDATA)>

<!--

The type of the reference – the value of this element can be service or interface.

-->

<!ELEMENT type (#PCDATA)>

<!--

The name under which the resource is registered in the JNDI.

-->

<!ELEMENT jndi-name (#PCDATA)>

<!--

The name of the security principal that will be used if the run-as identity is specified in the bean’s ejb-jar.xml. If this element is omitted, the EJB Container will choose a random user, mapped to the one specified in the ejb-jar.xml security role.

Example:

    <run-as-identity-map>
        <user-name>Administrator</user-name>
    </run-as-identity-map>
-->

<!ELEMENT run-as-identity-map (user-name)>

<!--

Specifies the security mechanisms that are supported by the J2EE Engine when a look up using IIOP is performed. These mechanisms are used according to Conformance Level 0 defined in the OMG’s Common Secure Interoperability V2 Specification.

-->

<!ELEMENT ior-security-config (transport-config?, as-context?, sas-context?)>

<!--

Defines the transport-layer security mechanism, that is, it defines the transport protocol and its configuration.

-->

<!ELEMENT transport-config (integrity, confidentiality, establish-trust-in-target, establish-trust-in-client)>

<!--

Specifies how the target processes integrity protected messages, that is, whether the J2EE Engine uses SSL during the course of the message process. The values of this element can be: required (the J2EE Engine uses SSL during the course of message process), supported (the J2EE Engine can use SSL during the course of message process), and none (the J2EE Engine does not use SSL during the course of message process).

-->

<!ELEMENT integrity (#PCDATA)>

<!--

Specifies whether the privacy protected messages will be encrypted. The values of this element can be: required (the J2EE Engine encrypts the messages), supported (the J2EE Engine provides options for encrypting the messages), and none (the J2EE Engine does not encrypt the messages).

-->

<!ELEMENT confidentiality (#PCDATA)>

<!--

Specifies whether the J2EE Engine authenticates to the client. The values of this element can be: supported (the J2EE Engine provides options for authentication to the client), and none (the J2EE Engine does not support authentication to the client).

-->

<!ELEMENT establish-trust-in-target (#PCDATA)>

<!--

Specifies whether the J2EE Engine authenticates the client. The values of this element can be: required (the J2EE Engine accepts connections only from clients who successfully authenticate in the handshake), supported (the J2EE Engine provides options for client authentication), and none (the J2EE Engine does not support client authentication).

-->

<!ELEMENT establish-trust-in-client (#PCDATA)>

<!--

Describes the authentication context.

-->

<!ELEMENT as-context (auth-method, realm, required)>

<!--

Specifies whether an authentication context will be used. The values of this element can be: username_password (the client must specify username and password when logging), and none (the as_context will not be used; authentication using transport level(s) or identity assertion will be used instead).

-->

<!ELEMENT auth-method (#PCDATA)>

<!--

The name of the realm, for which the specified username and password apply, if the authentication mechanism is used. The values of this element can be: default (the username and password apply to the whole realm) and none (the username and password do not apply to the current realm).

-->

<!ELEMENT realm (#PCDATA)>

<!--

Specifies whether this authentication method is required or optional. The values of this element can be: true or false.

-->

<!ELEMENT required (#PCDATA)>

<!--

Specifies whether the security mechanism supports identity assertion or authorization attributes delivered in service context.

-->

<!ELEMENT sas-context (caller-propagation)>

<!--

The values of this element can be: required (the J2EE Engine accepts delegation tokens that indicate who has been endorsed to assert an identity and requires a delegation token that endorses the J2EE Engine as proxy for the client), supported (the J2EE Engine accepts delegation tokens that indicate who has been endorsed to assert an identity), and none (the J2EE Engine does not support identity assertion; the client identity will be obtained from the authentication layer(s).).

-->

<!ELEMENT caller-propagation (#PCDATA)>

<!--

Specifies information about the session beans in your application.

Example:

    <session-props>
        <property>
            <property-name>InitialSize</property-name>
            <property-value>0</property-value>
        </property>
       <property>
            <property-name>MaxSize</property-name>
            <property-value>1000</property-value>
        </property>
        <property>
            <property-name>ResizeStep</property-name>
            <property-value>1</property-value>
        </property>
        <property>
            <property-name>PoolClass</property-name>
            <property-value>
              com.sap.engine.services.ejb.util.pool.ContainerPoolImpl
            </property-value>
        </property>
    </session-props>
-->

<!ELEMENT session-props (session-timeout?, (passivation|keeps-open-resources)?, property*)>

<!--

The period (in seconds) since the session was last used, after which the EJB Container may destroy it. That is, the EJB Container performs the same operation as if the bean’s remove() method was invoked. The default session timeout is 36000 seconds. We recommend that the value of the session-timeout is longer than the expected duration of the methods; otherwise, this will lead to system errors. This property can be specified for stateful session beans only.

Example:
<session-timeout>36000</session-timeout>
-->

<!ELEMENT session-timeout (#PCDATA)>

<!--

Specifies whether the EJB Container passivates the bean instances. If this element is omitted in ejb-j2ee-engine.xml, the EJB Container will not passivate the bean instances. This property can be specified for stateful session beans only.

Example:
<passivation>
<passive-timeout>3600</passive-timeout>
<lrulimit>200</lrulimit>
</passivation>
-->

<!ELEMENT passivation (passive-timeout, lrulimit)>

<!--

The period (in seconds) since the bean’s passivation, after which the EJB Container clears the session bean’s instance from the swap and destroys the session. Any attempt to call a method from it will receive a system exception.

-->

<!ELEMENT passive-timeout (#PCDATA)>

<!--

The maximum number of active sessions in the EJB Container. Once this number is reached, the EJB Container passivates the session that was used least recently (LRU algorithm) and swaps its instance to the hard disk.

-->

<!ELEMENT lrulimit (#PCDATA)>

<!--

This element shows that the enterprise bean holds open resources. This means that the enterprise bean’s ejbPassivate() method must be executed before serializing the enterprise bean. This element is used only when the application is set to use failover.

-->

<!ELEMENT keeps-open-resources EMPTY>

<!--

Specifies information about the entity beans in your application.

-->

<!ELEMENT entity-props (unknown-pk-interval?, initial-cache-size?, property*)>

<!--

If a primary key is not defined for an entity bean, this specifies the interval for the values of the primary key. By default the EJB Container creates primary keys of type long for beans whose primary keys are not defined.

-->

<!ELEMENT unknown-pk-interval (#PCDATA)>

<!--

The initial size of the Persistence Manager cache. This property can be specified for container-managed entity beans only.

-->

<!ELEMENT initial-cache-size (#PCDATA)>

<!--

Specifies information about the message-driven beans in your application.

Example:

    <message-props>
        <destination-name>myTopic</destination-name>
        <connection-factory-name>myTopicFactory</connection-factory-name>
        <property>
            <property-name>InitialSize</property-name>
            <property-value>0</property-value>
        </property>
        <property>
            <property-name>MaxSize</property-name>
            <property-value>1000</property-value>
        </property>
        <property>
            <property-name>ResizeStep</property-name>
            <property-value>1</property-value>
        </property>
        <property>
            <property-name>PoolClass</property-name>
            <property-value>
           com.sap.engine.services.ejb.util.pool.BlockingContainerPoolImpl
            </property-value>
        </property>
        <property>
            <property-name>topic-on-all-nodes</property-name>
            <property-value>true</property-value>
        </property>
        <property>
            <property-name>reconnect-attempts</property-name>
            <property-value>50</property-value>
        </property>
        <property>
            <property-name>sleep-between-attempts</property-name>
            <property-value>45000</property-value>
        </property>

</message-props>

-->

<!ELEMENT message-props (destination-name?, connection-factory-name?, property*)>

<!ELEMENT destination-name (#PCDATA)>

<!--

The name of the connection factory that will be used by the EJB Container to obtain connections in order to register the bean as a message listener.

-->

<!ELEMENT connection-factory-name (#PCDATA)>

<!--

Specifies the enterprise bean’s additional properties.

-->

<!ELEMENT property (property-name, property-value)>

<!--

The name of the property. Can be one of the following:

Pool Properties

● InitialSize
The initial number of instances that will be created in the pool.

● MaxSize
The maximum number of instances that can exist in the pool.

● ResizeStep
The number, by which the total number of instances in the pool will be incremented each time a new instance is requested and there are no idle instances in the pool. The value of this element must be positive.

● PoolClass
The implementation class of the pool. The possible values for this property are:

○ com.sap.engine.services.ejb.util.pool.ContainerPoolImpl (the default one),

○ com.sap.engine.services.ejb.util.pool.BlockingContainerPoolImpl

○ Your own implementation that is a subclass of com.sap.engine.services.ejb.util.pool.ContainerPoolImpl.

If you change the default PoolClass from ContainerPoolImpl to BlockingContainerPoolImpl, this affects the pool behavior when a new instance is requested and there are no idle instances in the pool. Whereas ContainerPoolImpl creates new instances each time when requested (no matter if the MaxSize is reached), the BlockingContainerPoolImpl will wait until an instance is released and thus ensures that the number of instances in the pool will never exceed the value of the MaxSize property.

Note

The InitialSize, MaxSize, ResizeStep, and PoolClass properties can be set for stateless session beans, message-driven beans, and entity beans because their containers use pools with instances. These properties are not available for stateful session beans as their instances are not kept in pools.

Stateful Failover

● stateful-failover
Enables stateful failover for stateful session beans. The possible values for this property are true and false. For more information, see Structure link Failover for Enterprise Beans.

Message-Driven Beans Specific Properties

● topic-on-all-nodes
This property can only be specified for message-driven beans subscribed to a destination of type Topic. Possible values: true and false. If set to true, the message-driven bean will be activated on each server process in the cluster. Thus, each message will be received on each server process. This functionality can be used by the application for cluster communication for example. By default, the value of this property is false, that is, only one connection consumer is registered for the application, thus ensuring that each message will be received only once by the same message-driven bean.

● reconnect-attempts
In case the container receives a notification by the JMS system that a connection is not active any more, this property specifies the number of attempts the EJB Container performs to recreate the JMS connection. The default value is 10. The interval between two consecutive attempts is determined by the sleep-between-attempts property.

● sleep-between-attempts
Specifies the interval (in milliseconds) between two consecutive attempts of the EJB Container to recreate an inactive JMS connection. The default value is 1000.

Recommendation

The default values of the reconnect-attempts and sleep-between-attempts properties are considered optimal for a typical message-driven beans scenario, and enough for the JMS system to recover from a server process failure. We recommend that you modify these values only in case of complicated scenarios (for example, involving more than one cluster).

-->

<!ELEMENT property-name (#PCDATA)>

<!--

The value of the specified property.

-->

<!ELEMENT property-value (#PCDATA)>

<!--

Specifies the isolation levels for the container-managed entity beans in the jar.

Example1:

    <transaction-descriptor>
        <isolation-level>
            <method>
                <ejb-name>myEJB</ejb-name>
                <method-intf>Remote</method-intf>
                <method-name>myMethod</method-name>
                <method-params>
                    <method-param>java.lang.String</method-param>
                    <method-param>java.lang.Integer</method-param>
                </method-params>
            </method>
            <isolation-attribute>Repeatable</isolation-attribute>
        </isolation-level>
    </transaction-descriptor>

Example2:

    <transaction-descriptor>
        <isolation-level>
            <ejb-name>myEJB</ejb-name>
            <isolation-attribute>Repeatable</isolation-attribute>
        </isolation-level>
    </transaction-descriptor>
-->

<!ELEMENT transaction-descriptor (isolation-level+)>

<!--

Sets isolation level for the entire enterprise bean, or for some of its methods.

-->

<!ELEMENT isolation-level ((method|ejb-name)+, isolation-attribute)>

<!--

Describes the method to which a transaction attribute will be set.

-->

<!ELEMENT method (ejb-name, method-intf?, method-name, method-params?)>

<!--

The interface in which the method is defined.

-->

<!ELEMENT method-intf (#PCDATA)>

<!--

The name of the method.

-->

<!ELEMENT method-name (#PCDATA)>

<!ELEMENT method-params (method-param*)>

<!--

The parameters of the method, if they are defined in the method.

-->

<!ELEMENT method-param (#PCDATA)>

<!--

The type of the isolation level – it can be ReadCommitted or Repeatable Read. The corresponding values for this element are Committed (for isolation level Read Committed) and Repeatable (for isolation level Repeatable Read). The default isolation level is Read Committed.

Example:

<isolation-attribute>Committed</isolation-attribute>

-->

<!ELEMENT isolation-attribute (#PCDATA)>

<!--

Contains a list of security role mappings to users or groups.

Example 1:

    <security-permission>
        <security-role-map>
            <role-name>Peter</role-name>
            <user-name>Administrator</user-name>
            <group-name>Administrators</group-name>
        </security-role-map>
    </security-permission>

Example 2:

    <security-permission>
        <security-role-map>
            <role-name>Jane</role-name>
            <server-role-name>Guest</server-role-name>
        </security-role-map>
    </security-permission>
-->

<!ELEMENT security-permission (security-role-map+)>

<!--

Maps security roles to existing server security roles. The mapping to users and groups is deprecated and should not be used.

-->

<!ELEMENT security-role-map (role-name, ((user-name*, group-name*) | server-role-name))>

<!--

The name of the security role that will be mapped.

-->

<!ELEMENT role-name (#PCDATA)>

<!--

A user that is already defined in the server environment and to which the security role will be mapped. Do not specify this element, its usage is deprecated.

-->

<!ELEMENT user-name (#PCDATA)>

<!--

A group that is already defined in the server environment and to which the security role will be mapped. Do not specify this element, its usage is deprecated.

-->

<!ELEMENT group-name (#PCDATA)>

<!--

A predefined security role in the root policy configuration of the J2EE Engine to which the current security role will be mapped.

-->

<!ELEMENT server-role-name (#PCDATA)>