com.goldencode.p2j.persist

Class AdaptiveFind

java.lang.Object

com.goldencode.p2j.persist.AdaptiveFind

public class AdaptiveFind
extends java.lang.Object

This instance is a wrapper to an implementation of AdaptiveQuery which may begin in dynamic record retrieval mode. If so, it switches to preselect mode as soon as possible. It is intended as the backing implementation for converted FIND statements which can be executed in succession without requiring a new query to be executed for each record retrieved. Candidates are combinations of FIND FIRST/NEXT and FIND LAST/PREV, or instances of FIND NEXT and FIND PREV which operate in loops.

This type of query by its nature operates only on a single table and therefore on a single record buffer. If the record buffer already is in use, its latest record is used as a reference point for the next record to be retrieved and the query is initialized in dynamic mode. Otherwise, the query is initialized in preselect mode.

The wrapped query will always be re-created if the query's buffers (saved at the AdaptiveFind's instantiation) have been bound to other buffers (i.e. the referenced buffer has switched).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	AdaptiveFind.AdaptiveFindQuery The wrapped query to which the query navigation calls are delegated.

Field Summary

Fields

Modifier and Type	Field and Description
private DataModelObject	dmo The original DMO reference used to create this instance.
private DataModelObject[]	externalDMOs The original external DMOs references used for initialization.
private java.util.List<java.util.function.Consumer<AdaptiveFind.AdaptiveFindQuery>>	init The list of query initialization actions which will be applied to query, when it will be created.
private boolean	initialized Flag indicating whether this object has been initialized
private AdaptiveFind.AdaptiveFindQuery	query The real wrapped query.

Constructor Summary

Constructors

Constructor and Description
AdaptiveFind() Default constructor.

Method Summary

Modifier and Type	Method and Description
private void	checkQuery() Check the query if the referenced buffers have changed their bound buffers.
private void	createQuery() Create the query - this will apply all recorded initialization steps.
boolean	first() Retrieve the first composite row of results for the query.
boolean	first(LockType lockType) Retrieve the first composite row of results for the query.
AdaptiveFind	initialize(DataModelObject dmo, java.lang.String where, java.lang.String sort, boolean inverseSorting, DataModelObject... dmos) Convenience deferred initializer designed for a single-table adaptive query.
AdaptiveFind	initialize(DataModelObject dmo, java.lang.String where, java.lang.String sort, DataModelObject... dmos) Convenience deferred initializer designed for a single-table adaptive query.
AdaptiveFind	initialize(DataModelObject dmo, java.lang.String where, java.lang.String sort, LockType lockType, DataModelObject... dmos) Convenience deferred initializer designed for a single-table adaptive query.
boolean	next() Retrieve the next composite row of results for the query.
boolean	next(LockType lockType) Retrieve the next composite row of results for the query.
boolean	silentFirst() Retrieve the first composite row of results for the query.
boolean	silentFirst(LockType lockType) Retrieve the first composite row of results for the query.
boolean	silentNext() Retrieve the next composite row of results for the query.
boolean	silentNext(LockType lockType) Retrieve the next composite row of results for the query.

Methods inherited from class java.lang.Object

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

Field Detail

query

private AdaptiveFind.AdaptiveFindQuery query

The real wrapped query.

init

private java.util.List<java.util.function.Consumer<AdaptiveFind.AdaptiveFindQuery>> init

The list of query initialization actions which will be applied to query, when it will be created.

initialized

private boolean initialized

Flag indicating whether this object has been initialized

dmo

private DataModelObject dmo

The original DMO reference used to create this instance.

externalDMOs

private DataModelObject[] externalDMOs

The original external DMOs references used for initialization.

Constructor Detail

AdaptiveFind

public AdaptiveFind()

Default constructor. Initialization is deferred until initialize() is called.

Method Detail

initialize

public AdaptiveFind initialize(DataModelObject dmo,
                               java.lang.String where,
                               java.lang.String sort,
                               DataModelObject... dmos)

Convenience deferred initializer designed for a single-table adaptive query. The where clause must expect no substitution parameters. A share lock will be applied to retrieved records.

Parameters:

dmo - DMO proxy which defines buffer and record type.

where - FQL where clause. May be null.

sort - FQL order by clause.

dmos - Zero or more external buffers.

Returns:

The current instance (this) so that chaining can be used.

initialize

public AdaptiveFind initialize(DataModelObject dmo,
                               java.lang.String where,
                               java.lang.String sort,
                               LockType lockType,
                               DataModelObject... dmos)

Convenience deferred initializer designed for a single-table adaptive query. The where clause must expect no substitution parameters.

Parameters:

dmo - DMO proxy which defines buffer and record type.

where - FQL where clause. May be null.

sort - FQL order by clause.

lockType - Lock type to apply to records retrieved by this query.

dmos - Zero or more external buffers.

Returns:

The current instance (this) so that chaining can be used.

initialize

public AdaptiveFind initialize(DataModelObject dmo,
                               java.lang.String where,
                               java.lang.String sort,
                               boolean inverseSorting,
                               DataModelObject... dmos)

Convenience deferred initializer designed for a single-table adaptive query. The where clause must expect no substitution parameters. A share lock will be applied to retrieved records.

Parameters:

dmo - DMO proxy which defines buffer and record type.

where - FQL where clause. May be null.

sort - FQL order by clause.

inverseSorting - Whether this query has the inverse sorting direction.

dmos - Zero or more external buffers.

Returns:

The current instance (this) so that chaining can be used.

next

public boolean next()

Retrieve the next composite row of results for the query. The underlying buffer is updated with the appropriate record.

Returns:

true if query could retrive the next record successfully; false if unsuccessful and lenientOffEnd is set on true.

Throws:

ErrorConditionException - if the query or the fetch of any record fails, or if no records are available and the query is set to fail in this case.

QueryOffEndException - if no records are available and the query is set not to fail in this case.

java.lang.IllegalStateException - if no query component has been added to this query.

next

public boolean next(LockType lockType)

Retrieve the next composite row of results for the query. The underlying buffer is updated with the appropriate record.

Parameters:

lockType - Lock type to apply to records retrieved (overrides default lock type set for each query component).

Returns:

true if query could retrive the next record successfully; false if unsuccessful and lenientOffEnd is set on true.

Throws:

ErrorConditionException - if the query or the fetch of any record fails, or if no records are available and the query is set to fail in this case.

QueryOffEndException - if no records are available and the query is set not to fail in this case.

java.lang.IllegalStateException - if no query component has been added to this query.

silentNext

public boolean silentNext()

Retrieve the next composite row of results for the query. The underlying buffer is updated with the appropriate record.

This operation is executed in silent mode.

Returns:

true if query could retrive the next record successfully; false if unsuccessful and lenientOffEnd is set on true.

Throws:

ErrorConditionException - if the query or the fetch of any record fails, or if no records are available and the query is set to fail in this case.

QueryOffEndException - if no records are available and the query is set not to fail in this case.

java.lang.IllegalStateException - if no query component has been added to this query.

silentNext

public boolean silentNext(LockType lockType)

Retrieve the next composite row of results for the query. The underlying buffer is updated with the appropriate record.

This operation is executed in silent mode.

Parameters:

lockType - Lock type to apply to records retrieved (overrides default lock type set for each query component).

Returns:

true if query could retrive the next record successfully; false if unsuccessful and lenientOffEnd is set on true.

Throws:

ErrorConditionException - if the query or the fetch of any record fails, or if no records are available and the query is set to fail in this case.

QueryOffEndException - if no records are available and the query is set not to fail in this case.

java.lang.IllegalStateException - if no query component has been added to this query.

first

public boolean first()

Retrieve the first composite row of results for the query. The underlying buffer is updated with the appropriate record.

Returns:

true if query could retrive the first record successfully; false if unsuccessful and lenientOffEnd is set on true.

Throws:

ErrorConditionException - if the query or the fetch of any record fails, or if no records are available and the query is set to fail in this case.

QueryOffEndException - if no records are available and the query is set not to fail in this case.

java.lang.IllegalStateException - if no query component has been added to this query.

first

public boolean first(LockType lockType)

Retrieve the first composite row of results for the query. The underlying buffer is updated with the appropriate record.

Parameters:

lockType - Lock type to apply to records retrieved (overrides default lock type set for each query component).

Returns:

true if query could retrive the first record successfully; false if unsuccessful and lenientOffEnd is set on true.

Throws:

ErrorConditionException - if the query or the fetch of any record fails, or if no records are available and the query is set to fail in this case.

QueryOffEndException - if no records are available and the query is set not to fail in this case.

java.lang.IllegalStateException - if no query component has been added to this query.

silentFirst

public boolean silentFirst()

Retrieve the first composite row of results for the query. The underlying buffer is updated with the appropriate record.

This operation is executed in silent mode.

Returns:

true if query could retrive the first record successfully; false if unsuccessful and lenientOffEnd is set on true.

Throws:

ErrorConditionException - if the query or the fetch of any record fails, or if no records are available and the query is set to fail in this case.

QueryOffEndException - if no records are available and the query is set not to fail in this case.

java.lang.IllegalStateException - if no query component has been added to this query.

silentFirst

public boolean silentFirst(LockType lockType)

Retrieve the first composite row of results for the query. The underlying buffer is updated with the appropriate record.

This operation is executed in silent mode.

Parameters:

lockType - Lock type to apply to records retrieved (overrides default lock type set for each query component).

Returns:

true if query could retrive the first record successfully; false if unsuccessful and lenientOffEnd is set on true.

Throws:

ErrorConditionException - if the query or the fetch of any record fails, or if no records are available and the query is set to fail in this case.

QueryOffEndException - if no records are available and the query is set not to fail in this case.

java.lang.IllegalStateException - if no query component has been added to this query.

createQuery

private void createQuery()

Create the query - this will apply all recorded initialization steps.

checkQuery

private void checkQuery()

Check the query if the referenced buffers have changed their bound buffers. If so, close it, so createQuery() will be initialized.