Oracle TopLink with EJB CMP 2.0 Beans

How-To Document

January 2006

After reading this How-To document, you will be able to:

• Map TopLink-enabled CMP entities.

• Configure TopLink for EJB 2.0 within the server.

• Deploy TopLink EJB 2.0 CMP entities to the server.

• Persist objects to a relational database.

• Query and modify EJBs from a Java client.

<ejb-jar>
  <enterprise-beans>
    <entity>
      <ejb-name>Account</ejb-name>
      <local-home>examples.ejb.cmp20.singlebean.AccountHome</local-home>
      <local>examples.ejb.cmp20.singlebean.Account</local>
      <ejb-class>examples.ejb.cmp20.singlebean.AccountBean</ejb-class>
      <persistence-type>Container</persistence-type>
      <prim-key-class>java.math.BigDecimal</prim-key-class>
      <reentrant>False</reentrant>
      <cmp-version>2.x</cmp-version>
...

<toplink:object-persistence ...>
   <opm:name>Account</opm:name>
   <opm:class-mapping-descriptors>
      <opm:class-mapping-descriptor xsi:type="toplink:relational-class-mapping-descriptor">
         <opm:class>examples.ejb.cmp20.singlebean.AccountBean</opm:class>
         <opm:alias>AccountBean</opm:alias>
         <opm:primary-key>...</opm:primary-key>
         <opm:querying>
            <opm:queries>
               <opm:query toplink:name="findLargeAccounts" xsi:type="toplink:read-all-query">
                  <arguments>...</arguments>
                  <toplink:bind-all-parameters>false</toplink:bind-all-parameters>
                  <toplink:cache-statement>false</toplink:cache-statement>
                  <toplink:call xsi:type="ejbql-call">
                     <toplink:ejbql>SELECT OBJECT(account) FROM AccountBean account WHERE account.balance > ?1</toplink:ejbql>
                  </toplink:call>
             <toplink:reference-class>examples.ejb.cmp20.singlebean.AccountBean</toplink:reference-class>
                  <toplink:cache-usage>conform</toplink:cache-usage>
               </opm:query>
            ... (other queries)
            </opm:queries>
         </opm:querying>
         <opm:attribute-mappings>...(mapped attributes)</opm:attribute-mapping>
         <toplink:descriptor-type>independent</toplink:descriptor-type>
         <toplink:sequencing>
            <toplink:sequence-name>ACCOUNT_SEQ</toplink:sequence-name>
            <toplink:sequence-field table="EJB_ACCOUNT" name="ACCOUNT_ID" xsi:type="opm:column"/>
         </toplink:sequencing>
         <toplink:caching>
            <toplink:always-conform>true</toplink:always-conform>
         </toplink:caching>
         <toplink:instantiation/>
         <toplink:copying/>
         <toplink:tables>
            <toplink:table name="EJB_ACCOUNT"/>
         </toplink:tables>
      </opm:class-mapping-descriptor>
   </opm:class-mapping-descriptors>
   <toplink:login xsi:type="database-login">
   ... (database login information)
   </toplink:login>
</toplink:object-persistence>

ejbCreate(): AccountBean id: (null) owner: (Peter Jones) balance: (0.0)
UPDATE EJB_ACCOUNT_SEQ SET SEQ_VALUE = SEQ_VALUE + 50 WHERE SEQ_NAME = 'ACCOUNT_SEQ'
SELECT SEQ_VALUE FROM EJB_ACCOUNT_SEQ WHERE SEQ_NAME = 'ACCOUNT_SEQ'
INSERT INTO EJB_ACCOUNT (ACCOUNT_ID, BALANCE, OWNER) VALUES (861, 0.0, 'Peter Jones')

try {
  account = createAccount(null, 0.0, "Peter Jones");
  } catch (Exception exception) {
  ...
  }

public void createAccount(String anAccountNumber, double aBalance,  String anOwner) throws CreateException, NamingException, RemoteException {
  try {
    AccountHome home = getAccountHome();
    Account account = null;
    account = home.create(anAccountNumber, aBalance, anOwner);
    } catch (Exception ex) {
    ex.printStackTrace();
    }
  }

public Account findOneBySQL(String queryString, java.util.Vector params) throws FinderException;

Oracle TopLink, 10g Release 3 (10.1.3)

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