de.ipcon.db.castor

Class MEXPersistenceQueryResults

java.lang.Object

de.ipcon.db.castor.MEXPersistenceQueryResults

All Implemented Interfaces:

de.ipcon.db.core.QueryResultsI, java.io.Closeable, java.lang.AutoCloseable, java.util.Iterator

public class MEXPersistenceQueryResults
extends java.lang.Object
implements de.ipcon.db.core.QueryResultsI

A specialized QueryResultsI implementation that supports MEX transformation before execution.

This class acts as a decorator and orchestrator. It uses a MEXTransformer to parse the query string for custom expressions (like @union, @fulltext, or @prefetch). These expressions are evaluated into standard OQL/SQL or registered as side-effect metadata (e.g. adding to the prefetch path list).

If a transformation results in multiple discrete queries (e.g. via a Union evaluator), this class iterates through them sequentially, providing a seamless unified iterator interface to the caller.

Constructor Summary

Constructors

Constructor and Description
MEXPersistenceQueryResults(CastorPersistenceHandler _ph, java.lang.String _query, java.lang.Object[] _parms, FulltextSearcherI _fts) Constructs the results object and executes the MEX transformation pipeline.
MEXPersistenceQueryResults(CastorPersistenceHandler _ph, java.lang.String _query, java.lang.Object[] _parms, FulltextSearcherI _fts, short _mode)

Method Summary

Modifier and Type	Method and Description
void	addPrefetchPath(java.lang.String path) Registers a relation path for eager loading.
void	addUnionQuery(QueryHandlerI qh) Appends a query to the internal execution sequence.
void	assureNotClosed()
void	cancel() Terminates the current query and prevents any further iteration by jumping the index to the end of the query list.
void	close()
java.lang.String	currentTag()
short	getMode()
java.lang.Object[]	getParms()
CastorPersistenceHandler	getPersistenceHandler()
java.lang.String[]	getPrefetchPaths()
boolean	hasNext() Coordinates the transition between multiple underlying query iterators.
boolean	isClosed()
java.lang.Object	next()
void	remove()

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.ipcon.db.core.QueryResultsI

spliterator, stream

Methods inherited from interface java.util.Iterator

forEachRemaining

Constructor Detail

MEXPersistenceQueryResults

public MEXPersistenceQueryResults(CastorPersistenceHandler _ph,
                                  java.lang.String _query,
                                  java.lang.Object[] _parms,
                                  FulltextSearcherI _fts)

Constructs the results object and executes the MEX transformation pipeline.

Parameters:

_ph - The persistence handler. Must be open.

_query - The raw query string containing potential MEX expressions.

_parms - The positional parameters for the query.

_fts - The full-text search engine instance for @fulltext evaluation.

_mode - The lock mode to apply to all resulting queries.

Throws:

MEXUnavailableException - if a MEX expression is recognized but cannot be resolved.

MEXPersistenceQueryResults

public MEXPersistenceQueryResults(CastorPersistenceHandler _ph,
                                  java.lang.String _query,
                                  java.lang.Object[] _parms,
                                  FulltextSearcherI _fts,
                                  short _mode)

Method Detail

getPersistenceHandler

public CastorPersistenceHandler getPersistenceHandler()

getParms

public java.lang.Object[] getParms()

getMode

public short getMode()

addUnionQuery

public void addUnionQuery(QueryHandlerI qh)

Appends a query to the internal execution sequence. Usually called by the UnionEvaluator during the transformation phase.

addPrefetchPath

public void addPrefetchPath(java.lang.String path)

Registers a relation path for eager loading. Usually called by the PrefetchEvaluator during transformation.

getPrefetchPaths

public java.lang.String[] getPrefetchPaths()

assureNotClosed

public void assureNotClosed()

close

public void close()

Specified by:

close in interface de.ipcon.db.core.QueryResultsI

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

isClosed

public boolean isClosed()

Specified by:

isClosed in interface de.ipcon.db.core.QueryResultsI

hasNext

public boolean hasNext()

Coordinates the transition between multiple underlying query iterators.

When the currentQI is exhausted, this method automatically closes it, advances to the next QueryHandlerI in the list, and initializes a new iterator. This process continues until all queries are exhausted.

Specified by:

hasNext in interface java.util.Iterator

Returns:

true if the current or any subsequent query has more results.

next

public java.lang.Object next()

Specified by:

next in interface java.util.Iterator

remove

public void remove()

Specified by:

remove in interface java.util.Iterator

currentTag

public java.lang.String currentTag()

Specified by:

currentTag in interface de.ipcon.db.core.QueryResultsI

cancel

public void cancel()

Terminates the current query and prevents any further iteration by jumping the index to the end of the query list.

Specified by:

cancel in interface de.ipcon.db.core.QueryResultsI