QueryResults (Castor JavaDoc)

java.lang.Object
- org.exolab.castor.persist.QueryResults

```
public final class QueryResults
extends java.lang.Object
```
The result of a query in the context of a transaction. A query is executed against the cache engine in the context of a transaction. The result of a query is this object that can be used to obtain the next object in the query.

Version:

$Revision: 7951 $ $Date: 2006-04-22 11:05:30 -0600 (Sat, 22 Apr 2006) $

Author:

Assaf Arkin

Constructor Summary

Constructors
Constructor	Description
`QueryResults(TransactionContext tx, LockEngine engine, PersistenceQuery query, AccessMode accessMode, Database db)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`absolute(int row)`
`void`	`close()`	Close the query and release all resources held by the query.
`java.lang.Object`	`fetch()`	Loads the specified object with the identity.
`PersistenceQuery`	`getQuery()`	Returns the associated query.
`java.lang.Class`	`getResultType()`	Returns the type of object returned by this query.
`TransactionContext`	`getTransaction()`	Returns the transaction context in which this query was opened.
`java.lang.Object`	`nextIdentity()`	Returns the identity of the next object to be returned.
`int`	`size()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - QueryResults
```
public QueryResults(TransactionContext tx,
                    LockEngine engine,
                    PersistenceQuery query,
                    AccessMode accessMode,
                    Database db)
```
- Method Detail
  - getTransaction
```
public TransactionContext getTransaction()
```
    Returns the transaction context in which this query was opened. The transaction may be closed.
    
    Returns:
    
    The query's transaction context
  - getQuery
```
public PersistenceQuery getQuery()
```
    Returns the associated query.
    
    Returns:
    
    The query
  - getResultType
```
public java.lang.Class getResultType()
```
    Returns the type of object returned by this query.
    
    Returns:
    
    The type of object returned by this query
  - nextIdentity
```
public java.lang.Object nextIdentity()
                              throws PersistenceException
```
    Returns the identity of the next object to be returned. Calling this method multiple time will skip objects. When the result set has been exhuasted, this method will return null.
    
    Returns:
    
    The identity of the next object
    
    Throws:
    
    PersistenceException - An error reported by the persistence engine
    
    TransactionNotInProgressException - The transaction has been closed
  - fetch
```
public java.lang.Object fetch()
                       throws PersistenceException
```
    Loads the specified object with the identity. The identity must have been retrieved with a call to nextIdentity().
    If the object is locked by another transaction this method will block until the lock is released, or a timeout occured. If a timeout occurs or the object has been deleted by the other transaction, this method will report an. The query may proceed to the next identity.
    If the object has been deleted in this transaction, this method will report an. However, the caller may iterate to and obtain the next object.
    This method is equivalent to TransactionContext.fetch(org.exolab.castor.persist.ClassMolder, org.exolab.castor.persist.spi.Identity, org.exolab.castor.mapping.AccessMode) with a know cache engine, identity and lock and acts on the query results rather than issuing a new query to load the object.
    
    Returns:
    
    The loaded object
    
    Throws:
    
    PersistenceException - An error reported by the persistence engine. The object was not found in persistent storage. The transaction has been closed. Could not acquire a lock on the object.
  - close
```
public void close()
```
    Close the query and release all resources held by the query.
  - absolute
```
public boolean absolute(int row)
                 throws PersistenceException
```
    Throws:
    
    PersistenceException
  - size
```
public int size()
         throws PersistenceException
```
    Throws:
    
    PersistenceException

Class QueryResults

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

QueryResults

Method Detail

getTransaction

getQuery

getResultType

nextIdentity

fetch

close

absolute

size