Cursor (Oracle Fusion Middleware Java API Reference for Oracle TopLink)

java.lang.Object
- org.eclipse.persistence.queries.Cursor

All Implemented Interfaces:

java.io.Serializable, java.util.Enumeration, java.util.Iterator

Direct Known Subclasses:

CursoredStream, ScrollableCursor
```
public abstract class Cursor
extends java.lang.Object
implements java.util.Enumeration, java.util.Iterator, java.io.Serializable
```
Purpose: Abstract class for CursoredStream and ScrolableCursor

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type Field and Description

CursorPolicy policy
Query policy that initialize the stream.

ReadQuery query
Read query that initialize the stream.

Fields
Modifier and Type	Field and Description
`CursorPolicy`	`policy` Query policy that initialize the stream.
`ReadQuery`	`query` Read query that initialize the stream.

Constructor Summary

Constructors
Constructor and Description

Cursor()
INTERNAL: Default constructor.

Cursor(org.eclipse.persistence.internal.databaseaccess.DatabaseCall call, CursorPolicy policy)
INTERNAL:

Constructors
Constructor and Description
`Cursor()` INTERNAL: Default constructor.
`Cursor(org.eclipse.persistence.internal.databaseaccess.DatabaseCall call, CursorPolicy policy)` INTERNAL:

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`clear()` PUBLIC: Release all objects read in so far.
`void`	`close()` PUBLIC: Closes the stream.
`org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor`	`getAccessor()` INTERNAL: Return the accessor associated with the cursor.
`org.eclipse.persistence.internal.sessions.AbstractSession`	`getExecutionSession()` INTERNAL: Returns the session the underlying call was executed on.
`java.util.Vector<org.eclipse.persistence.internal.helper.DatabaseField>`	`getFields()` INTERNAL: Return the fields for the stream.
`java.util.Map<java.lang.Object,java.lang.Object>`	`getInitiallyConformingIndex()` INTERNAL: Conforming instances found in memory when building the result.
`java.util.List<java.lang.Object>`	`getObjectCollection()` INTERNAL: Return the internal object collection that stores the objects.
`int`	`getPageSize()` INTERNAL: Return the number of items to be faulted in for the stream.
`CursorPolicy`	`getPolicy()` INTERNAL: Return the cursor policy.
`abstract int`	`getPosition()` INTERNAL: Return the position of the stream inside the object collection.
`ReadQuery`	`getQuery()` INTERNAL: Return the query associated with the stream.
`java.sql.ResultSet`	`getResultSet()` INTERNAL: Return the result set (cursor).
`Expression`	`getSelectionCriteriaClone()` INTERNAL: The clone of the selection criteria is needed for in-memory conforming each object read from the Cursor.
`org.eclipse.persistence.internal.sessions.AbstractSession`	`getSession()` INTERNAL: Return the handle to the session
`boolean`	`isClosed()` PUBLIC: Return if the stream is closed.
`void`	`remove()` PUBLIC: Remove is not support with cursors.
`void`	`setInitiallyConformingIndex(java.util.Map<java.lang.Object,java.lang.Object> index)` INTERNAL: Conforming instances found in memory when building the result.
`void`	`setObjectCollection(java.util.List<java.lang.Object> collection)` INTERNAL: Set the internal object collection
`void`	`setPolicy(CursorPolicy policy)` INTERNAL: Set the cursor policy.
`void`	`setSelectionCriteriaClone(Expression expression)` INTERNAL: The clone of the selection criteria is needed for in-memory conforming each object read from the Cursor.
`void`	`setSession(org.eclipse.persistence.internal.sessions.AbstractSession databaseSession)` INTERNAL: Set the session handle
`void`	`setSize(int size)` INTERNAL: Set the cache size
`void`	`setTranslationRow(org.eclipse.persistence.internal.sessions.AbstractRecord row)` INTERNAL: Sets the translation row this query was executed with.
`int`	`size()` PUBLIC: Retrieve the size of the open cursor by executing a count on the same query as the cursor.

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

Methods inherited from interface java.util.Enumeration
hasMoreElements, nextElement

Methods inherited from interface java.util.Iterator
hasNext, next

- Field Detail
  - query
```
public transient ReadQuery query
```
    Read query that initialize the stream.
  - policy
```
public transient CursorPolicy policy
```
    Query policy that initialize the stream.
- Constructor Detail
  - Cursor
```
public Cursor()
```
    INTERNAL: Default constructor.
  - Cursor
```
public Cursor(org.eclipse.persistence.internal.databaseaccess.DatabaseCall call,
      CursorPolicy policy)
```
    INTERNAL:
- Method Detail
  - close
```
public void close()
           throws DatabaseException
```
    PUBLIC: Closes the stream. This should be performed whenever the user has finished with the stream.
    
    Throws:
    
    DatabaseException
  - getAccessor
```
public org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor getAccessor()
```
    INTERNAL: Return the accessor associated with the cursor.
  - getFields
```
public java.util.Vector<org.eclipse.persistence.internal.helper.DatabaseField> getFields()
```
    INTERNAL: Return the fields for the stream.
  - getInitiallyConformingIndex
```
public java.util.Map<java.lang.Object,java.lang.Object> getInitiallyConformingIndex()
```
    INTERNAL: Conforming instances found in memory when building the result. These objects are returned first by the cursor, and a fast lookup is needed to make sure the same objects appearing in the cursor are filtered out.
  - getObjectCollection
```
public java.util.List<java.lang.Object> getObjectCollection()
```
    INTERNAL: Return the internal object collection that stores the objects.
  - getPageSize
```
public int getPageSize()
```
    INTERNAL: Return the number of items to be faulted in for the stream.
  - getPolicy
```
public CursorPolicy getPolicy()
```
    INTERNAL: Return the cursor policy.
  - getPosition
```
public abstract int getPosition()
```
    INTERNAL: Return the position of the stream inside the object collection.
  - getQuery
```
public ReadQuery getQuery()
```
    INTERNAL: Return the query associated with the stream.
  - getResultSet
```
public java.sql.ResultSet getResultSet()
```
    INTERNAL: Return the result set (cursor).
  - getSelectionCriteriaClone
```
public Expression getSelectionCriteriaClone()
```
    INTERNAL: The clone of the selection criteria is needed for in-memory conforming each object read from the Cursor.
  - getSession
```
public org.eclipse.persistence.internal.sessions.AbstractSession getSession()
```
    INTERNAL: Return the handle to the session
  - getExecutionSession
```
public org.eclipse.persistence.internal.sessions.AbstractSession getExecutionSession()
```
    INTERNAL: Returns the session the underlying call was executed on. This root session knows the database platform.
  - isClosed
```
public boolean isClosed()
```
    PUBLIC: Return if the stream is closed.
  - setInitiallyConformingIndex
```
public void setInitiallyConformingIndex(java.util.Map<java.lang.Object,java.lang.Object> index)
```
    INTERNAL: Conforming instances found in memory when building the result. These objects are returned first by the cursor, and a fast lookup is needed to make sure the same objects appearing in the cursor are filtered out.
  - setObjectCollection
```
public void setObjectCollection(java.util.List<java.lang.Object> collection)
```
    INTERNAL: Set the internal object collection
  - setPolicy
```
public void setPolicy(CursorPolicy policy)
```
    INTERNAL: Set the cursor policy.
  - setSelectionCriteriaClone
```
public void setSelectionCriteriaClone(Expression expression)
```
    INTERNAL: The clone of the selection criteria is needed for in-memory conforming each object read from the Cursor.
  - setSession
```
public void setSession(org.eclipse.persistence.internal.sessions.AbstractSession databaseSession)
```
    INTERNAL: Set the session handle
  - setSize
```
public void setSize(int size)
```
    INTERNAL: Set the cache size
  - setTranslationRow
```
public void setTranslationRow(org.eclipse.persistence.internal.sessions.AbstractRecord row)
```
    INTERNAL: Sets the translation row this query was executed with. Used for incremental conforming.
  - size
```
public int size()
         throws DatabaseException
```
    PUBLIC: Retrieve the size of the open cursor by executing a count on the same query as the cursor. If this cursor is conforming size() can only be an estimate. cursor size plus number of conforming instances found in memory will be returned. The union (actual result) may be smaller than this.
    
    Throws:
    
    DatabaseException
  - remove
```
public void remove()
            throws QueryException
```
    PUBLIC: Remove is not support with cursors.
    
    Specified by:
    
    remove in interface java.util.Iterator
    
    Throws:
    
    QueryException
  - clear
```
public void clear()
```
    PUBLIC: Release all objects read in so far. This should be performed when reading in a large collection of objects in order to preserve memory.

Class Cursor

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Enumeration

Methods inherited from interface java.util.Iterator

Field Detail

query

policy

Constructor Detail

Cursor

Cursor

Method Detail

close

getAccessor

getFields

getInitiallyConformingIndex

getObjectCollection

getPageSize

getPolicy

getPosition

getQuery

getResultSet

getSelectionCriteriaClone

getSession

getExecutionSession

isClosed

setInitiallyConformingIndex

setObjectCollection

setPolicy

setSelectionCriteriaClone

setSession

setSize

setTranslationRow

size

remove

clear