An example of such a thing:

@OneToMany(mappedBy="transaction")
private Set taxComponents = new HashSet(1);

I understand why sets are used but as I’m in control of what gets put in I can safely use:

@OneToMany(mappedBy="transaction")
 private Collection taxComponents = new ArrayList(1);
 

So using set’s is great but it comes at a cost and beware it’s not just fetches but deletes and inserts have a similar issue in that they get deleted one by one and then reinserted to ensure uniqueness, so if you do update the set it also has a performance hit.

The performance of the major report moved from 30 mins to 6 mins, still not lightning fast but a good improvement. I could of course move to native SQL but I didn’t want to have to rewrite a load of code to do that.

On your class that is implementing the interface you need to use the name attribute: -

@Stateful(name="xxx.AssetTypeOverrideService")
public class AssetTypeOverrideService implements OverrideService{

@Stateful(name="xxxRuleTypeOverrideService")
public class RuleTypeOverrideService implements OverrideService {

Then on the bean you want inject these into you use:

@EJB(beanName="xxx.AssetTypeOverrideService")
private OverrideService assetOverrideService;
	
@EJB(beanName="xxx.RuleTypeOverrideService")
private OverrideService ruleTypeOverrideService;

The name can be anything you want I just think it’s logical to keep it the same as the class and the beanName obviously is the same value of the bean you want to inject that has the correct implementation.

It seems easy now but it did make me stop and think.

The first @EntityListerners which accepts an array of classes that will become your event handlers:

@EntityListeners(ErrorListener.class)
public class SystemError implements Serializable {

The next is to annotate the methods in your listener class that will handle the various events. The annotations that can be used are:

@PrePersist Executed before the entity manager persist operation is actually executed or cascaded. This call is synchronous with the persist operation.

@PreRemove Executed before the entity manager remove operation is actually executed or cascaded. This call is synchronous with the remove operation.

@PostPersist Executed after the entity manager persist operation is actually executed or cascaded. This call is invoked after the database INSERT is executed.

@PostRemove Executed after the entity manager remove operation is actually executed or cascaded. This call is synchronous with the remove operation.

@PreUpdate Executed before the database UPDATE operation.

@PostUpdate Executed after the database UPDATE operation.

@PostLoad Eexecuted after an entity has been loaded into the current persistence context or an entity has been refreshed.

Note that if you are using EJB dependency injection it won’t work in your listener as it’s not managed by your container buy you can use jndi: -

Context ctx = new InitialContext();
XXXService service = (XXXService) ctx.lookup("EARNAME/XXXServiceBean/local");

To start with a create a simple helper class that converts String to LocalDate and LocatDate to String

public static LocalDate createLocalDateForString(String dateString){
  DateTimeFormatter fmt = DateTimeFormat.forPattern("yyyyMMdd");
  return StringUtils.isEmpty(value) ? null :  fmt.parseDateTime(dateString).toLocalDate();	
}
    
    public static String createStringForLocalDate(LocalDate date){
    	return date.toString("yyyyMMdd"); 
    }

Next is to create your own user type. This is done by implementing org.hibernate.usertype.UserType. The main methods I’m implement are

public Object nullSafeGet(ResultSet rs, String[] names, Object owner)
			throws HibernateException, SQLException {
		LocalDate result = null;
		String dateAsString = rs.getString(names[0]);
		if(!rs.wasNull()){
			result = StringUtils.isNotEmpty(dateAsString) ? DateHelper.createLocalDateForString(dateAsString) : null;
		}
		return result;
	}

public void nullSafeSet(PreparedStatement statement, Object value, int index)
			throws HibernateException, SQLException {
		if(value == null){
			statement.setNull(index, SQL_TYPES[0]);
		}else{
			String dateAsString = DateHelper.createStringForLocalDate((LocalDate)value);
			statement.setString(index, dateAsString);
		}
}

All that is left is to add the annotation to each of your entity properties that you want to use as LocalDate.

@org.hibernate.annotations.Type(type = "xxx.LocalDateUserType")

In my persistence.xml I added the following to the properties of my persistence-unit:-

<property name="hibernate.search.default.indexBase" value="PATH TO YOUR INDEX DIRECTORY"/>
<property name="hibernate.ejb.post-insert" value="org.hibernate.search.event.FullTextIndexEventListener"/>
<property name="hibernate.ejb.post-update" value="org.hibernate.search.event.FullTextIndexEventListener"/>
<property name="hibernate.ejb.post-delete" value="org.hibernate.search.event.FullTextIndexEventListener"/>

The path of your index base can be anywhere you want as long as the application has permission to write to it.

To used hibernate search you need to identify and highlight all of the classes that you want to search, you also need to identify each of the properties that you want indexed and the indexing strategy, you can find out what the various types are here Hibernate Search

@Indexed(index="index_direcory")
public class SomeClass

@Field(index=Index.TOKENIZED, analyzer = @Analyzer(impl = LowerCaseAnalyser.class))
@Column(name = "inv_name", length = 200, nullable = true)
private String name;

Inject an instance of FullTextEntityManager into your code. I used a stateless session bean that was used throughout the application

@In
private FullTextEntityManger entityManager;

I used a three different query types, RegEx, Prefix and WildCard.

RegexQuery(new Term(fieldName,".*[^-'\\w]" + searchString.toLowerCase() + "(\\s|$)"));
PrefixQuery(new Term(fieldName,searchString.toLowerCase()));
WildcardQuery(new Term(fieldName,'*'+searchString.toLowerCase()+'*'));

The regex one was used to search for firstname surname i.e. Jo Bloggs. The prefix query was used to search for Jo* i.e. Joanne, Jo Bloggs. The wildcard one, the most expensive one, was used to search for *Jo* i.e. Jones, BillyJoBloggs. The fieldname is the obviously the name of the field, so in:-

@Field(index=Index.TOKENIZED, analyzer = @Analyzer(impl = LowerCaseAnalyser.class))
private String name;  

FiledName would = name

All that is left to do it actually query the index and this is done by:

entityManager.createFullTextQuery(query,SomeClass.class).getResultList();

This has been in production for a some time now and it’s been stable and performed well. There has only been one instance to date of the index getting screwed up but I catered for that and enable the index to be rebuilt. I also had to provide this as any update to the indexed fields via direct sql wouldn’t be updated.

Db = Sybase
AppServer = JBoss 4.2.3
Java = 1.6
Persistance = EJB3 implemented by Hibernate
Hibernate = 3.4.0.GA

So the first thing I do is to create a named native query on my entity which looks something like this:

@NamedNativeQuery(name="StoredProc_Call",
                  query="stored_proc_name(:param1, :param2, :param3)",
                  hints={
                      @QueryHint(name = "org.hibernate.callable",value = "true"), 
                      @QueryHint(name = "org.hibernate.readOnly",value = "true")
                  },
                  resultSetMapping="scalar", resultClass=Result.class)

@SqlResultSetMapping(name="scalar",columns=@ColumnResult(name="result")

Because I’m using hibernate as my EJB3 implementation, the default for JBoss, I can use it to call the stored proc for me using the hints attribute which takes in an array of queryhint objects.

Because native scalar results aren’t supported by EJB3 you also have to set the resultClass and the resultSetMapping.

@SqlResultSetMapping(name="scalar",columns=@ColumnResult(name="result")

All that is required now is to create the native query, set the required parameters and call it.

Query query = entityManager.createNamedQuery("StoredProc_Call");