EclipseLink Core 4.0.2 · org.eclipse.persistence.queries.CursoredStream

Modifier and Type	Field and Description
protected int	marker Marker for backing up.

Access	Constructor and Description
public	CursoredStream() INTERNAL: Initialize the state of the stream
public	CursoredStream(DatabaseCall call, CursoredStreamPolicy policy) INTERNAL: Initialize the state of the stream

Method Summary

Modifier and Type	Method and Description
public boolean	atEnd() PUBLIC: Return whether the cursored stream is at its end.
public int	available() PUBLIC: Returns the number of objects that can be read from this input without blocking.
public Expression	buildCountDistinctExpression(List<E> includeFields, ExpressionBuilder builder) INTERNAL: Must build the count on the primary key fields, not * as * is not allowed if there was a distinct.
public void	clear() Overrides org.eclipse.persistence.queries.Cursor.clear. PUBLIC: Release all objects read in so far.
protected List<Object>	copy(int startIndex, int endIndex) INTERNAL: Answer a list of the elements of the receiver's collection from startIndex to endIndex.
protected int	getCursorSize() Implements abstract org.eclipse.persistence.queries.Cursor.getCursorSize. INTERNAL: Retrieve the size of the open cursor by executing a count on the same query as the cursor.
protected int	getInitialReadSize() INTERNAL: Return the threshold for the stream.
protected int	getMarker() INTERNAL: Return the marker used for mark() & reset() operations.
public int	getPageSize() Overrides org.eclipse.persistence.queries.Cursor.getPageSize. INTERNAL: Return the page size for the stream.
public int	getPosition() Implements abstract org.eclipse.persistence.queries.Cursor.getPosition. INTERNAL: Return the position of the stream inside the object collection
public boolean	hasMoreElements() Implements java.util.Enumeration.hasMoreElements. PUBLIC: Return whether the cursored stream has any more elements.
public boolean	hasNext() Implements java.util.Iterator.hasNext. PUBLIC: Return whether the cursored stream has any more elements.
public void	mark(int Limit on the number of characters that may be read while still preserving the mark. Because the stream's input comes from the database, there is no actual limit, so this argument is ignored. readAheadLimit) PUBLIC: Mark the present position in the stream.
public boolean	markSupported() PUBLIC: Tests if this input stream supports the `mark` and `reset` methods.
public Object	Returns: the next object in stream next() Implements java.util.Iterator.next. PUBLIC: Return the next object from the collection, if beyond the read limit read from the cursor.
public List<Object>	Returns: the next objects in stream next(int numberOfElements) PUBLIC: Return a Vector of at most numberOfElements of the next objects from the collection.
public Object	Returns: the next object in stream nextElement() Implements java.util.Enumeration.nextElement. PUBLIC: Return the next object from the collection, if beyond the read limit read from the cursor.
public Vector<E>	Returns: the next objects in stream nextElements(int numberOfElements) PUBLIC: Return a Vector of at most numberOfElements of the next objects from the collection.
public Object	peek() PUBLIC: Return the next object in the stream, without incrementing the stream's position.
public Object	Returns: - next object in stream read() PUBLIC: This method differs slightly from conventional read() operation on a Java stream.
public List<Object>	Returns: - vector containing next number of objects read(int - number of objects to be returned number) PUBLIC: This method differs slightly from conventional read() operation on a Java stream.
public void	releasePrevious() PUBLIC: Release all objects read in so far.
public void	reset() PUBLIC: Repositions this stream to the position at the time the mark method was last called on this stream.
protected Object	retrieveNextObject() Implements abstract org.eclipse.persistence.queries.Cursor.retrieveNextObject. INTERNAL: Read the next row from the result set.
protected Object	retrieveNextPage() INTERNAL: Retrieve and add the next page size of rows to the vector.
protected void	setLimits() INTERNAL: Initialize the stream size and position
protected void	setMarker(int value) INTERNAL: Set the marker used for mark() & reset() operations

marker	back to summary
protected int marker Marker for backing up.

CursoredStream	back to summary
public CursoredStream() INTERNAL: Initialize the state of the stream

CursoredStream	back to summary
public CursoredStream(DatabaseCall call, CursoredStreamPolicy policy) INTERNAL: Initialize the state of the stream

Method Detail

atEnd	back to summary
public boolean atEnd() throws DatabaseException PUBLIC: Return whether the cursored stream is at its end.

available	back to summary
public int available() throws DatabaseException PUBLIC: Returns the number of objects that can be read from this input without blocking.

buildCountDistinctExpression	back to summary
public Expression buildCountDistinctExpression(List<E> includeFields, ExpressionBuilder builder) INTERNAL: Must build the count on the primary key fields, not * as * is not allowed if there was a distinct. This require a manually defined operator. added for CR 2900

clear	back to summary
public void clear() Overrides org.eclipse.persistence.queries.Cursor.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. Annotations @Override

clear

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public void clear()

Overrides org.eclipse.persistence.queries.Cursor.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.

Annotations

@Override

copy	back to summary
protected List<Object> copy(int startIndex, int endIndex) throws QueryException INTERNAL: Answer a list of the elements of the receiver's collection from startIndex to endIndex.

getCursorSize	back to summary
protected int getCursorSize() throws DatabaseException, QueryException Implements abstract org.eclipse.persistence.queries.Cursor.getCursorSize. INTERNAL: Retrieve the size of the open cursor by executing a count on the same query as the cursor. Annotations @Override

getCursorSize

back to summary

protected int getCursorSize() throws DatabaseException, QueryException

Implements abstract org.eclipse.persistence.queries.Cursor.getCursorSize.

INTERNAL: Retrieve the size of the open cursor by executing a count on the same query as the cursor.

Annotations

@Override

getInitialReadSize	back to summary
protected int getInitialReadSize() INTERNAL: Return the threshold for the stream.

getMarker	back to summary
protected int getMarker() INTERNAL: Return the marker used for mark() & reset() operations.

getPageSize	back to summary
public int getPageSize() Overrides org.eclipse.persistence.queries.Cursor.getPageSize. INTERNAL: Return the page size for the stream. Annotations @Override

getPageSize

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public int getPageSize()

Overrides org.eclipse.persistence.queries.Cursor.getPageSize.

INTERNAL: Return the page size for the stream.

Annotations

@Override

getPosition	back to summary
public int getPosition() Implements abstract org.eclipse.persistence.queries.Cursor.getPosition. INTERNAL: Return the position of the stream inside the object collection Annotations @Override

getPosition

back to summary

public int getPosition()

Implements abstract org.eclipse.persistence.queries.Cursor.getPosition.

INTERNAL: Return the position of the stream inside the object collection

Annotations

@Override

hasMoreElements back to summary

hasMoreElements	back to summary
public boolean hasMoreElements() Implements java.util.Enumeration.hasMoreElements. PUBLIC: Return whether the cursored stream has any more elements. Returns:boolean Doc from java.util.Enumeration.hasMoreElements. `true` if and only if this enumeration object contains at least one more element to provide; `false` otherwise. Annotations @Override

public boolean hasMoreElements()

Implements java.util.Enumeration.hasMoreElements.

PUBLIC: Return whether the cursored stream has any more elements.

Returns:boolean

Doc from java.util.Enumeration.hasMoreElements.

true if and only if this enumeration object contains at least one more element to provide; false otherwise.

Annotations

@Override

hasNext back to summary

hasNext	back to summary
public boolean hasNext() Implements java.util.Iterator.hasNext. PUBLIC: Return whether the cursored stream has any more elements. Returns:boolean Doc from java.util.Iterator.hasNext. `true` if the iteration has more elements Annotations @Override

public boolean hasNext()

Implements java.util.Iterator.hasNext.

PUBLIC: Return whether the cursored stream has any more elements.

Returns:boolean

Doc from java.util.Iterator.hasNext.

true if the iteration has more elements

Annotations

@Override

mark	back to summary
public void mark(int readAheadLimit) PUBLIC: Mark the present position in the stream. Subsequent calls to reset() will attempt to reposition the stream to this point. Parameters readAheadLimit:int Limit on the number of characters that may be read while still preserving the mark. Because the stream's input comes from the database, there is no actual limit, so this argument is ignored.

mark

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public void mark(int readAheadLimit)

PUBLIC: Mark the present position in the stream. Subsequent calls to reset() will attempt to reposition the stream to this point.

Parameters

readAheadLimit:int: Limit on the number of characters that may be read while still preserving the mark. Because the stream's input comes from the database, there is no actual limit, so this argument is ignored.

markSupported	back to summary
public boolean markSupported() PUBLIC: Tests if this input stream supports the `mark` and `reset` methods. The `markSupported` method of `InputStream` returns `false`.

next	back to summary
public Object next() Implements java.util.Iterator.next. PUBLIC: Return the next object from the collection, if beyond the read limit read from the cursor. Returns:Object the next object in stream Annotations @Override

back to summary

public Object next()

Implements java.util.Iterator.next.

PUBLIC: Return the next object from the collection, if beyond the read limit read from the cursor.

Returns:Object

the next object in stream

Annotations

@Override

next	back to summary
public List<Object> next(int numberOfElements) PUBLIC: Return a Vector of at most numberOfElements of the next objects from the collection. If there aren't that many objects left to read, just return what is available. Returns:List<Object> the next objects in stream

back to summary

public List<Object> next(int numberOfElements)

PUBLIC: Return a Vector of at most numberOfElements of the next objects from the collection. If there aren't that many objects left to read, just return what is available.

Returns:List<Object>: the next objects in stream

nextElement	back to summary
public Object nextElement() Implements java.util.Enumeration.nextElement. PUBLIC: Return the next object from the collection, if beyond the read limit read from the cursor. Returns:Object the next object in stream Annotations @Override

nextElement

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public Object nextElement()

Implements java.util.Enumeration.nextElement.

PUBLIC: Return the next object from the collection, if beyond the read limit read from the cursor.

Returns:Object

the next object in stream

Annotations

@Override

nextElements	back to summary
public Vector<E> nextElements(int numberOfElements) PUBLIC: Return a Vector of at most numberOfElements of the next objects from the collection. If there aren't that many objects left to read, just return what is available. Returns:Vector<E> the next objects in stream

nextElements

back to summary

public Vector<E> nextElements(int numberOfElements)

PUBLIC: Return a Vector of at most numberOfElements of the next objects from the collection. If there aren't that many objects left to read, just return what is available.

Returns:Vector<E>: the next objects in stream

peek	back to summary
public Object peek() throws DatabaseException PUBLIC: Return the next object in the stream, without incrementing the stream's position.

read	back to summary
public Object read() 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 Returns:Object - next object in stream Exceptions DatabaseException: if read pass end of stream

read

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public Object read() 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

Returns:Object

- next object in stream

Exceptions

DatabaseException:: if read pass end of stream

read	back to summary
public List<Object> read(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 object from the collection, if beyond the read limit read from the cursor Parameters number:int - number of objects to be returned Returns:List<Object> - vector containing next number of objects Exceptions DatabaseException: if read pass end of stream

read

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public List<Object> read(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 object from the collection, if beyond the read limit read from the cursor

Parameters

number:int: - number of objects to be returned

Returns:List<Object>

- vector containing next number of objects

Exceptions

DatabaseException:: if read pass end of stream

releasePrevious	back to summary
public void releasePrevious() 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.

reset	back to summary
public void reset() PUBLIC: Repositions this stream to the position at the time the mark method was last called on this stream.

retrieveNextObject	back to summary
protected Object retrieveNextObject() throws DatabaseException Implements abstract org.eclipse.persistence.queries.Cursor.retrieveNextObject. Doc from org.eclipse.persistence.queries.Cursor.retrieveNextObject. INTERNAL: Read the next row from the result set. Annotations @Override

retrieveNextObject

back to summary

protected Object retrieveNextObject() throws DatabaseException

Implements abstract org.eclipse.persistence.queries.Cursor.retrieveNextObject.

Doc from org.eclipse.persistence.queries.Cursor.retrieveNextObject.

INTERNAL: Read the next row from the result set.

Annotations

@Override

retrieveNextPage	back to summary
protected Object retrieveNextPage() throws DatabaseException INTERNAL: Retrieve and add the next page size of rows to the vector. Return the last object, or null if at end.

setLimits	back to summary
protected void setLimits() INTERNAL: Initialize the stream size and position

setMarker	back to summary
protected void setMarker(int value) INTERNAL: Set the marker used for mark() & reset() operations

public Class CursoredStream

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail