com.jalios.jcms.search

Class DataIterator<E>

java.lang.Object

com.jalios.jcms.search.DataIterator<E>

Type Parameters:

E - the type being iterated

All Implemented Interfaces:

java.util.Iterator<E>

public class DataIterator<E>
extends java.lang.Object
implements java.util.Iterator<E>

DataIterator allowing efficient iteration over hybrid sources of Data (JStore and/or JcmsDB) with size retrieval.

Warning : elements will not be sorted accross sources, JStore objects are iterated first, then JcmsDB object are iterated !

This iterator does not support remove operation.

Example to iterate all Publication object :

    DataIterator<Publication> iterator = new DataIterator<Publication>();
    
    // JStore
    TreeSet<Publication> jStorePubSet = new TreeSet<Publication>(channel.getDataSet(Publication.class));
    iterator.addCollection(jStorePubSet);
     
    // JcmsDB
    for(Class<? extends Publication> clazz : channel.getDBPublicationClassList()) {
      ScrollableResults sr = HibernateUtil.getSession().createCriteria(clazz).scroll();
      int dbcount = HibernateUtil.queryCountExact(clazz, null);
      iterator.addScrollableResults(sr, dbcount);
    }
 

Since:

jcms-6.0.1

Constructor Summary

Constructors

Constructor and Description
DataIterator() Creates a new empty DataIterator.
DataIterator(java.util.Collection<? extends E> coll) Creates a new DataIterator to iterate the specified Collection of objects.
DataIterator(java.util.Collection<? extends E> coll, org.hibernate.ScrollableResults sr, int dbcount) Creates a new DataIterator to iterate both the specified Collection the JcmsDB results.
DataIterator(org.hibernate.ScrollableResults sr, int dbcount) Creates a new DataIterator to iterate the specified JcmsDB results.

Method Summary

Modifier and Type	Method and Description
void	addCollection(java.util.Collection<? extends E> coll) Add the specified Collection to the element to iterate.
void	addDBClass(java.lang.Class<?> clazz) Add the specified DB Class to the element to iterate.
void	addScrollableResults(org.hibernate.ScrollableResults sr, int dbcount) Add the specified ScrollableResults to the element to iterate.
boolean	hasNext() Returns true if the iteration has more elements.
E	next() Returns the next element in the iteration.
void	remove() Unsupported Operation
int	size() Return the total number of object available in the iteration.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Iterator

forEachRemaining

Constructor Detail

DataIterator

public DataIterator()

Creates a new empty DataIterator.

DataIterator

public DataIterator(java.util.Collection<? extends E> coll)

Creates a new DataIterator to iterate the specified Collection of objects.

Parameters:

coll - a collection to iterate

DataIterator

public DataIterator(org.hibernate.ScrollableResults sr,
                    int dbcount)

Creates a new DataIterator to iterate the specified JcmsDB results.

Parameters:

sr - the JcmsDB ScrollableResults.

dbcount - the number or result returned in the ScrollableResults.

DataIterator

public DataIterator(java.util.Collection<? extends E> coll,
                    org.hibernate.ScrollableResults sr,
                    int dbcount)

Creates a new DataIterator to iterate both the specified Collection the JcmsDB results.

Parameters:

coll - the collection to iterate (can be null, in which case iterate on collection is skipped).

sr - the JcmsDB ScrollableResults.

dbcount - the number or result returned in the ScrollableResults.

Method Detail

addCollection

public void addCollection(java.util.Collection<? extends E> coll)

Add the specified Collection to the element to iterate.

Parameters:

coll - the Collection to iterate (can be null, in which case iterate on collection is skipped).

Throws:

java.lang.IllegalStateException - if the iteration has already begun

addScrollableResults

public void addScrollableResults(org.hibernate.ScrollableResults sr,
                                 int dbcount)

Add the specified ScrollableResults to the element to iterate.

Parameters:

sr - the JcmsDB ScrollableResults.

dbcount - the number or result returned in the ScrollableResults.

Throws:

java.lang.IllegalStateException - if the iteration has already begun

addDBClass

public void addDBClass(java.lang.Class<?> clazz)

Add the specified DB Class to the element to iterate.

Parameters:

clazz - a class of data inside the database

Throws:

java.lang.IllegalStateException - if the iteration has already begun

Since:

jcms-7.0.0

hasNext

public boolean hasNext()

Returns true if the iteration has more elements. (In other words, returns true if next would return an element rather than throwing an exception.)

Specified by:

hasNext in interface java.util.Iterator<E>

Returns:

true if the iterator has more elements.

next

public E next()

Returns the next element in the iteration. Calling this method repeatedly until the hasNext() method returns false will return each element in the underlying collection exactly once.

Specified by:

next in interface java.util.Iterator<E>

Returns:

the next element in the iteration.

Throws:

java.util.NoSuchElementException - iteration has no more elements.

size

public int size()

Return the total number of object available in the iteration.

Warning : When used with JcmsDB results, the correctness of this number depends on the parameters specified at construction time !

Returns:

the number of object being iterated

remove

public void remove()

Unsupported Operation

Specified by:

remove in interface java.util.Iterator<E>

Throws:

java.lang.UnsupportedOperationException