ScrollableCursor (EclipseLink 2.6.4, API Reference)

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

All Implemented Interfaces:

java.io.Serializable, java.util.Enumeration, java.util.Iterator, java.util.ListIterator
```
public class ScrollableCursor
extends Cursor
implements java.util.ListIterator
```
See Also:
Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`protected boolean`	`atEndOfCursor` Internal flag indicating if the end of the cursor has been reached
`protected java.lang.Object`	`nextObject`
`protected java.lang.Object`	`previousObject`
`protected org.eclipse.persistence.internal.sessions.AbstractRecord`	`previousRow` Store the previous row, for 1-m joining.

Fields inherited from class org.eclipse.persistence.queries.Cursor
executionSession, fields, initiallyConformingIndex, nextRow, objectCollection, policy, position, query, resultSet, selectionCriteriaClone, session, size, statement, translationRow

Constructor Summary

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

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`absolute(int rows)` PUBLIC: Moves the cursor to the given row number in the result set
`void`	`add(java.lang.Object object)` PUBLIC: Add is not support for scrollable cursors.
`void`	`afterLast()` PUBLIC: Moves the cursor to the end of the result set, just after the last row.
`void`	`beforeFirst()` PUBLIC: Moves the cursor to the front of the result set, just before the first row
`protected void`	`clearNextAndPrevious()` INTERNAL: Clear the cached next and previous object and row values.
`protected void`	`clearNextAndPreviousObject()` INTERNAL: Clear only the cached next and previous object values.
`int`	`currentIndex()` PUBLIC: Retrieves the current row index number
`boolean`	`first()` PUBLIC: Moves the cursor to the first row in the result set
`protected int`	`getCursorSize()` INTERNAL: Retrieve the size of the open cursor by executing a count on the same query as the cursor.
`protected int`	`getKnownCursorSize()`
`protected java.lang.Object`	`getNextObject()`
`int`	`getPosition()` PUBLIC: Retrieves the current cursor position (current row).
`protected java.lang.Object`	`getPreviousObject()`
`boolean`	`hasMoreElements()` PUBLIC: Indicates whether the cursor can move to the the next row
`boolean`	`hasNext()` PUBLIC: Indicates whether the cursor can move to the the next row
`boolean`	`hasNextElement()` PUBLIC: Indicates whether the cursor can move to the the next row
`boolean`	`hasPrevious()` PUBLIC: Indicates whether the cursor can move to the the previous row
`boolean`	`isAfterLast()` PUBLIC: Indicates whether the cursor is after the last row in the result set.
`boolean`	`isBeforeFirst()` PUBLIC: Indicates whether the cursor is before the first row in the result set.
`boolean`	`isFirst()` PUBLIC: Indicates whether the cursor is on the first row of the result set.
`boolean`	`isLast()` PUBLIC: Indicates whether the cursor is on the last row of the result set.
`boolean`	`last()` PUBLIC: Moves the cursor to the last row in the result set
`protected void`	`loadNext()` Load the next object
`protected void`	`loadPrevious()` Load the previous object.
`java.lang.Object`	`next()` PUBLIC: This method differs slightly from conventional read() operation on a Java stream.
`java.util.List<java.lang.Object>`	`next(int number)` PUBLIC: This method differs slightly from conventional read() operation on a Java stream.
`java.lang.Object`	`nextElement()` PUBLIC: Return the next object from the collection, if beyond the read limit read from the cursor.
`int`	`nextIndex()` PUBLIC: Retrieves the next row index (against the current row)
`java.lang.Object`	`previous()` PUBLIC: Return the previous object from the collection.
`int`	`previousIndex()` PUBLIC: Retrieves the previous row index (against the current row)
`boolean`	`relative(int rows)` PUBLIC: Moves the cursor a relative number of rows, either positive or negative.
`protected java.lang.Object`	`retrieveNextObject()` INTERNAL: Read the next row from the result set.
`protected java.lang.Object`	`retrievePreviousObject()` INTERNAL: CR#4139 Read the previous row from the result set.
`void`	`set(java.lang.Object object)` PUBLIC: Set is not supported for scrollable cursors.
`protected void`	`setNextObject(java.lang.Object nextObject)`
`protected void`	`setPreviousObject(java.lang.Object previousObject)`

Methods inherited from class org.eclipse.persistence.queries.Cursor
buildAndRegisterObject, clear, close, finalize, getAccessor, getExecutionSession, getFields, getInitiallyConformingIndex, getObjectCollection, getPageSize, getPolicy, getQuery, getResultSet, getSelectionCriteriaClone, getSession, getStatement, getTranslationRow, isClosed, remove, setExecutionSession, setFields, setInitiallyConformingIndex, setObjectCollection, setPolicy, setPosition, setResultSet, setSelectionCriteriaClone, setSession, setSize, setTranslationRow, size

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

Methods inherited from interface java.util.ListIterator
remove

- Field Detail
  - nextObject
```
protected transient java.lang.Object nextObject
```
  - previousObject
```
protected transient java.lang.Object previousObject
```
  - previousRow
```
protected org.eclipse.persistence.internal.sessions.AbstractRecord previousRow
```
    Store the previous row, for 1-m joining.
  - atEndOfCursor
```
protected boolean atEndOfCursor
```
    Internal flag indicating if the end of the cursor has been reached
- Constructor Detail
  - ScrollableCursor
```
public ScrollableCursor()
```
    INTERNAL: Default constructor.
  - ScrollableCursor
```
public ScrollableCursor(org.eclipse.persistence.internal.databaseaccess.DatabaseCall call,
                ScrollableCursorPolicy policy)
```
    INTERNAL: constructor.
- Method Detail
  - absolute
```
public boolean absolute(int rows)
                 throws DatabaseException
```
    PUBLIC: Moves the cursor to the given row number in the result set
    
    Throws:
    
    DatabaseException
  - add
```
public void add(java.lang.Object object)
         throws QueryException
```
    PUBLIC: Add is not support for scrollable cursors.
    
    Specified by:
    
    add in interface java.util.ListIterator
    
    Throws:
    
    QueryException
  - afterLast
```
public void afterLast()
               throws DatabaseException
```
    PUBLIC: Moves the cursor to the end of the result set, just after the last row.
    
    Throws:
    
    DatabaseException
  - beforeFirst
```
public void beforeFirst()
                 throws DatabaseException
```
    PUBLIC: Moves the cursor to the front of the result set, just before the first row
    
    Throws:
    
    DatabaseException
  - clearNextAndPrevious
```
protected void clearNextAndPrevious()
```
    INTERNAL: Clear the cached next and previous object and row values. This must be called whenever the cursor is re-positioned.
  - clearNextAndPreviousObject
```
protected void clearNextAndPreviousObject()
```
    INTERNAL: Clear only the cached next and previous object values. Called by previous() and next() to maintain the cached next and previous row values.
  - currentIndex
```
public int currentIndex()
                 throws DatabaseException
```
    PUBLIC: Retrieves the current row index number
    
    Throws:
    
    DatabaseException
  - first
```
public boolean first()
              throws DatabaseException
```
    PUBLIC: Moves the cursor to the first row in the result set
    
    Throws:
    
    DatabaseException
  - getCursorSize
```
protected int getCursorSize()
                     throws DatabaseException
```
    INTERNAL: Retrieve the size of the open cursor by executing a count on the same query as the cursor.
    
    Specified by:
    
    getCursorSize in class Cursor
    
    Throws:
    
    DatabaseException
  - getKnownCursorSize
```
protected int getKnownCursorSize()
```
  - getNextObject
```
protected java.lang.Object getNextObject()
```
  - getPosition
```
public int getPosition()
                throws DatabaseException
```
    PUBLIC: Retrieves the current cursor position (current row). The first row is number 1, the second number 2, and so on. Unlike java.sql.ResultSet.getRow(), 0 is not returned if afterLast. Instead size() + 1 is returned.
    
    Specified by:
    
    getPosition in class Cursor
    
    Returns:
    the current row number; 0 if there is no current row
    
    Throws:
    
    DatabaseException - if a database access error occurs
  - getPreviousObject
```
protected java.lang.Object getPreviousObject()
```
  - hasMoreElements
```
public boolean hasMoreElements()
                        throws DatabaseException
```
    PUBLIC: Indicates whether the cursor can move to the the next row
    
    Specified by:
    
    hasMoreElements in interface java.util.Enumeration
    
    Throws:
    
    DatabaseException
  - hasNext
```
public boolean hasNext()
                throws DatabaseException
```
    PUBLIC: Indicates whether the cursor can move to the the next row
    
    Specified by:
    
    hasNext in interface java.util.Iterator
    
    Specified by:
    
    hasNext in interface java.util.ListIterator
    
    Throws:
    
    DatabaseException
  - hasNextElement
```
public boolean hasNextElement()
                       throws DatabaseException
```
    PUBLIC: Indicates whether the cursor can move to the the next row
    
    Throws:
    
    DatabaseException
  - hasPrevious
```
public boolean hasPrevious()
                    throws DatabaseException
```
    PUBLIC: Indicates whether the cursor can move to the the previous row
    
    Specified by:
    
    hasPrevious in interface java.util.ListIterator
    
    Throws:
    
    DatabaseException
  - isAfterLast
```
public boolean isAfterLast()
                    throws DatabaseException
```
    PUBLIC: Indicates whether the cursor is after the last row in the result set.
    
    Throws:
    
    DatabaseException
  - isBeforeFirst
```
public boolean isBeforeFirst()
                      throws DatabaseException
```
    PUBLIC: Indicates whether the cursor is before the first row in the result set.
    
    Throws:
    
    DatabaseException
  - isFirst
```
public boolean isFirst()
                throws DatabaseException
```
    PUBLIC: Indicates whether the cursor is on the first row of the result set.
    
    Throws:
    
    DatabaseException
  - isLast
```
public boolean isLast()
               throws DatabaseException
```
    PUBLIC: Indicates whether the cursor is on the last row of the result set.
    
    Throws:
    
    DatabaseException
  - last
```
public boolean last()
             throws DatabaseException
```
    PUBLIC: Moves the cursor to the last row in the result set
    
    Throws:
    
    DatabaseException
  - loadNext
```
protected void loadNext()
```
    Load the next object
  - loadPrevious
```
protected void loadPrevious()
```
    Load the previous object. This is used solely for scrollable cursor support
  - next
```
public java.lang.Object next()
                      throws DatabaseException,
                             QueryException
```
    PUBLIC: This method differs slightly from conventional read() operation on a Java stream. This method return the next object in the collection rather than specifying the number of bytes to be read in. Return the next object from the collection, if beyond the read limit read from the cursor
    
    Specified by:
    
    next in interface java.util.Iterator
    
    Specified by:
    
    next in interface java.util.ListIterator
    
    Returns:
    - next object in stream
    
    Throws:
    
    DatabaseException - if read pass end of stream
    
    QueryException
  - next
```
public java.util.List<java.lang.Object> next(int number)
                                      throws DatabaseException
```
    PUBLIC: This method differs slightly from conventional read() operation on a Java stream. This method returns the next number of objects in the collection in a vector. Return the next specified number of objects from the collection, if beyond the read limit read from the cursor
    
    Parameters:
    number - - number of objects to be returned
    
    Returns:
    - vector containing next number of objects
    
    Throws:
    
    DatabaseException - if read pass end of stream
  - nextElement
```
public java.lang.Object nextElement()
                             throws DatabaseException,
                                    QueryException
```
    PUBLIC: Return the next object from the collection, if beyond the read limit read from the cursor.
    
    Specified by:
    
    nextElement in interface java.util.Enumeration
    
    Returns:
    next object in stream
    
    Throws:
    
    DatabaseException
    
    QueryException
  - nextIndex
```
public int nextIndex()
              throws DatabaseException
```
    PUBLIC: Retrieves the next row index (against the current row)
    
    Specified by:
    
    nextIndex in interface java.util.ListIterator
    
    Throws:
    
    DatabaseException
  - previous
```
public java.lang.Object previous()
                          throws DatabaseException,
                                 QueryException
```
    PUBLIC: Return the previous object from the collection.
    
    Specified by:
    
    previous in interface java.util.ListIterator
    
    Returns:
    - previous object in stream
    
    Throws:
    
    DatabaseException - if read pass first of stream
    
    QueryException
  - previousIndex
```
public int previousIndex()
                  throws DatabaseException
```
    PUBLIC: Retrieves the previous row index (against the current row)
    
    Specified by:
    
    previousIndex in interface java.util.ListIterator
    
    Throws:
    
    DatabaseException
  - relative
```
public boolean relative(int rows)
                 throws DatabaseException
```
    PUBLIC: Moves the cursor a relative number of rows, either positive or negative. Attempting to move beyond the first/last row in the result set positions the cursor before/after the the first/last row
    
    Throws:
    
    DatabaseException
  - retrieveNextObject
```
protected java.lang.Object retrieveNextObject()
                                       throws DatabaseException
```
    INTERNAL: Read the next row from the result set.
    
    Specified by:
    
    retrieveNextObject in class Cursor
    
    Throws:
    
    DatabaseException
  - retrievePreviousObject
```
protected java.lang.Object retrievePreviousObject()
                                           throws DatabaseException
```
    INTERNAL: CR#4139 Read the previous row from the result set. It is used solely for scrollable cursor support.
    
    Throws:
    
    DatabaseException
  - set
```
public void set(java.lang.Object object)
         throws QueryException
```
    PUBLIC: Set is not supported for scrollable cursors.
    
    Specified by:
    
    set in interface java.util.ListIterator
    
    Throws:
    
    QueryException
  - setNextObject
```
protected void setNextObject(java.lang.Object nextObject)
```
  - setPreviousObject
```
protected void setPreviousObject(java.lang.Object previousObject)
```

Class ScrollableCursor

Field Summary

Fields inherited from class org.eclipse.persistence.queries.Cursor

Constructor Summary

Method Summary

Methods inherited from class org.eclipse.persistence.queries.Cursor

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.ListIterator

Field Detail

nextObject

previousObject

previousRow

atEndOfCursor

Constructor Detail

ScrollableCursor

ScrollableCursor

Method Detail

absolute

add

afterLast

beforeFirst

clearNextAndPrevious

clearNextAndPreviousObject

currentIndex

first

getCursorSize

getKnownCursorSize

getNextObject

getPosition

getPreviousObject

hasMoreElements

hasNext

hasNextElement

hasPrevious

isAfterLast

isBeforeFirst

isFirst

isLast

last

loadNext

loadPrevious

next

next

nextElement

nextIndex

previous

previousIndex

relative

retrieveNextObject

retrievePreviousObject

set

setNextObject

setPreviousObject