How to initialize JpaTemplate through Constructor with EntityManager.

[samwun9988]

Hi, with JBOSS 7.1.1 Final and Hibernate 3.5 (for lucuene Search), I created an ejb module with the following Facade object and its interface:

Facade class:

@Stateless(name = "MyisamProductArticleFacade")

@Local(value = MyisamProductArticleFacadeLocal.class)

@Transactional

public class MyisamProductArticleFacade implements MyisamProductArticleFacadeLocal {

    private static final Logger logger = Logger.getLogger(MyisamProductArticleFacade.class);

    @PersistenceContext(unitName = "ForestSurfPU")

    private EntityManager em;

    JpaTemplate jpaTemplate;

    public MyisamProductArticleFacade() {

    }

    /**

     *

     * @param entityManagerFactory

     */

    @Autowired

    public MyisamProductArticleFacade(EntityManagerFactory entityManagerFactory) {

            this.jpaTemplate = new JpaTemplate(entityManagerFactory);

    }

    protected EntityManager getEntityManager() {

        return em;

    }

@Override

    public List<MyisamProductArticle> search(final String queryString) {

            final String[] fields = new String[]{"header", "a_desc"}; // search on these fields

           return (List) this.jpaTemplate.execute(new JpaCallback() {  // this.jpaTempalte is null.

                    @Override

                    public Object doInJpa(EntityManager em) throws PersistenceException {

                            List<MyisamProductArticle> results = new ArrayList<MyisamProductArticle>();

                            try {

                                    FullTextEntityManager fullTextEntityManager = Search.getFullTextEntityManager(em);

                                    org.apache.lucene.analysis.standard.StandardAnalyzer

                                            standardAnalyzer = new org.apache.lucene.analysis.standard.StandardAnalyzer(Version.LUCENE_35);

                                    MultiFieldQueryParser parser = new MultiFieldQueryParser(Version.LUCENE_35, fields, standardAnalyzer);

                                    org.apache.lucene.search.Query query = parser.parse(queryString);

                                    FullTextQuery fullTextQuery = fullTextEntityManager.createFullTextQuery(query, MyisamProductArticle.class);

                                    results = fullTextQuery.getResultList();

                            }

                            catch (Exception e) {

                                    throw new PersistenceException(e);

                            }

                            return results;

                    }

            });

    }

Facacde interface:

@Local

public interface MyisamProductArticleFacadeLocal {

   public List<MyisamProductArticle> search(String queryString);

}

But I ecounted the following exception when executing method search:

Caused by: java.lang.NullPointerException

        at ForestSurf.entity.facade.MyisamProductArticleFacade.search(MyisamProductArticleFacade.java:81) [ForestSurf-ejb-1.0.jar:]

        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.6.0_07]

But this.jpaTemplate is not being initialised in the constructor, which is still null here.

Is there anyway initilize the Facade object with constructor when the ejb project is loaded or somehow invoke this initialisation?

Any suggestion is very appreciated.

Thanks

Sam

[nickarls]

Tried a @PostConstruct?

[samwun9988]

I can't make @PostConstruct work for this constructor. It is not a springframework annotation.

How can I instruct spring mvc to initialise it?

I thought the following code will do:

@Autowired

    public MyisamProductArticleFacade(EntityManagerFactory entityManagerFactory) {

            this.jpaTemplate = new JpaTemplate(entityManagerFactory);

    }

but it doesn't get executed by spring.

Thanks

Sam

[samwun9988]

I found an example have the entityManagerFactory written in an ApplicationContext.xml file:

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">

        <property name="driverClassName" value="${jdbc.driverClassName}"/>

        <property name="url" value="${jdbc.url}"/>

        <property name="username" value="${jdbc.username}"/>

        <property name="password" value="${jdbc.password}"/>

        <property name="initialSize" value="5"/>

        <property name="maxActive" value="10"/>

        <property name="maxIdle" value="10"/>

        <property name="maxWait" value="1000"/>

        <property name="defaultAutoCommit" value="false"/>

    </bean>

  <!-- Spring-enabled container-managed JPA without any EJB container -->

    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">

        <property name="dataSource" ref="dataSource"/>

  <property name="persistenceUnitName" value="dbschema"/>       

  <property  name="jpaVendorAdapter">

  <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">

  <property name="showSql" value="true"/>

  <property name="generateDdl" value="true"/>

  <property name="database" value="MYSQL"/> <!-- dialect -->

  </bean>

  </property>

  <!--

  <property name="loadTimeWeaver">

  <bean class="org.springframework.instrument.classloading.SimpleLoadTimeWeaver"/>

  </property>

  -->

    </bean>

  <!-- needed for Local JDBC Transaction -->

  <bean id="jpaDialect" class="org.springframework.orm.jpa.vendor.HibernateJpaDialect"/>

    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">

        <property name="entityManagerFactory" ref="entityManagerFactory"/>

        <property name="jpaDialect" ref="jpaDialect"/>

    </bean>

</beans>

But my ejb project is using a persistence.xml file.

How do I tell my ejb project to inject entityManagerFactory?

Thanks

Sam

[nickarls]

I'm no Spring user,  but isn't @Stateless and @PersistenceContext standard EE annotations? Spring doesn't create the EJB:s themself, does it? Why doesn't @PostConstruct fire?

[samwun9988]

With @PostConstruct, I got this error:

annotation type not applicable to this kind of declaration

Here is the constructor:

@PostConstruct

    public MyisamProductArticleFacade(EntityManagerFactory entityManagerFactory) {

            this.jpaTemplate = new JpaTemplate(entityManagerFactory);

    }

Thanks

Sam

[nickarls]

Try just

@PersistenceUnit

EntityManagerFactory emf;

@PostConstruct

public init() {

  jpaTemplate = ...

}

[samwun9988]

Thank you for you for the suggestion. This has got rid of the exception.

The issue is the Hibernate Lucene Search does not return any result.

Here is the search function in the Facade class:

@Override

    public List<MyisamProductArticle> search(final String queryString) {

            final String[] fields = new String[]{"header", "a_desc"}; // search on these fields

            return (List) this.jpaTemplate.execute(new JpaCallback() {

                    @Override

                    public Object doInJpa(EntityManager em) throws PersistenceException {

                            List<MyisamProductArticle> results = new ArrayList<MyisamProductArticle>();

                            try {

                                    FullTextEntityManager fullTextEntityManager = Search.getFullTextEntityManager(em);

                                    org.apache.lucene.analysis.standard.StandardAnalyzer

                                            standardAnalyzer = new org.apache.lucene.analysis.standard.StandardAnalyzer(Version.LUCENE_35);

                                    MultiFieldQueryParser parser = new MultiFieldQueryParser(Version.LUCENE_35, fields, standardAnalyzer);

//                                    parser.setDefaultOperator(QueryParser.AND_OPERATOR); // overrides the default OR_OPERATOR, so that all words in the search are required

                                    org.apache.lucene.search.Query query = parser.parse(queryString);

                                    FullTextQuery fullTextQuery = fullTextEntityManager.createFullTextQuery(query, MyisamProductArticle.class);

                                    results = fullTextQuery.getResultList();

                            }

                            catch (Exception e) {

                                    throw new PersistenceException(e);

                            }

                            return results;

                    }

            });

    }

Thanks

Sam

[samwun9988]

This is the indexes of the database table of mysql:

mysql> show index from myisam_product_article;

+------------------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+

| Table                  | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |

+------------------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+

| myisam_product_article |          0 | PRIMARY  |            1 | article_id  | A         |           1 |     NULL | NULL   |      | BTREE      |         |               |

| myisam_product_article |          1 | a_desc   |            1 | a_desc      | NULL      |        NULL |     NULL | NULL   | YES  | FULLTEXT   |         |               |

| myisam_product_article |          1 | a_desc   |            2 | header      | NULL      |        NULL |     NULL | NULL   | YES  | FULLTEXT   |         |               |

+------------------------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+

3 rows in set (0.00 sec)

[samwun9988]

For reference, here is my MyisamProductArticle class:

@Indexed

@Analyzer(impl = org.apache.lucene.analysis.standard.StandardAnalyzer.class)

public class MyisamProductArticle implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id

    @Basic(optional = false)

    @DocumentId

    @NotNull

    @Column(name = "article_id")

    private Integer articleId;

    @Basic(optional = false)

    @NotNull

    @Column(name = "product_id")

    private int productId;

    @Lob

    @Size(max = 65535)

    @Column(name = "a_desc")

    // This annotation tells that this field has to be indexed and also analyzed (break the long sentence and ignore common words), store tells if this field

    // will be part of Index, by Store.Yes it means it will be part of Index, so that query will be faster, downside is that size of Index increases

    @Field(index = Index.YES, analyze = Analyze.YES, store = Store.YES)

    private String aDesc;

    @Size(max = 64)

    @Column(name = "header")

    // This annotation tells that this field has to be indexed and also analyzed (break the long sentence and ignore common words), store tells if this field

    // will be part of Index, by Store.Yes it means it will be part of Index, so that query will be faster, downside is that size of Index increases

    @Field(index = Index.YES, analyze = Analyze.YES, store = Store.YES)

    private String header;

[nickarls]

I think you will have more luck at the Lucene forum end (unless you can point some finger back at the AS)