com.sap.cloud.server.odata

Class DeltaStream

java.lang.Object

com.sap.cloud.server.odata.DataValue

com.sap.cloud.server.odata.DeltaStream

Direct Known Subclasses:

AtomDeltaStream, JsonDeltaStream

public abstract class DeltaStream
extends DataValue

A stream of delta items, each of which is either an EntityValue or a ChangedLink. While processing a stream, a delta link may be encountered, but it will not be immediately available to the caller. The DeltaStream.deltaLink can be obtained only after the stream is closed.

Example

let deltaStream = ...;
 while (deltaStream.next())
 {
     if (deltaStream.hasEntity())
     {
         let entity = deltaStream.getEntity();
         // Process entity value.
     }
     else
     {
         let link = deltaStream.getLink();
         // Process changed link.
     }
 }
 deltaStream.close();
 var deltaLink = deltaStream.deltaLink;
 // Save delta link for later use.
 

Field Summary

Fields inherited from class com.sap.cloud.server.odata.DataValue

undefined

Constructor Summary

Constructors

Constructor and Description
DeltaStream()

Method Summary

Modifier and Type	Method and Description
void	abort() Close this stream and release all associated resources, without checking first that the end of stream has been reached.
void	close() Close this stream and release all associated resources, checking first that the end of stream has been reached.
java.lang.Object	getCurrent() Return (nullable) the current delta item (an EntityValue or ChangedLink), or null if there is no current delta item.
DataType	getDataType() Return data type with a DataType.code of DataType.DELTA_STREAM.
java.lang.Object	getDeltaItem() Return (nullable) The current delta item (an EntityValue or ChangedLink), or null.
java.lang.String	getDeltaLink() Return (nullable) The delta-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.
EntityValue	getEntity() Return the current entity value.
ChangedLink	getLink() Return the current changed link.
java.lang.String	getNextLink() Return (nullable) The next-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.
java.lang.String	getReadLink() Return (nullable) The read-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.
boolean	hasCurrent() Return true if the if the stream has a current delta item (the most recent call to DeltaStream.next returned true and DeltaStream.close has not been called)).
boolean	hasEntity() Check if the stream has a current delta item which is an entity value.
boolean	hasLink() Check if the stream has a current delta item which is a changed link.
boolean	isClosed() Return has DeltaStream.close been called?
abstract boolean	next() If this stream has not been DeltaStream.close and has a next delta item, then advance to the next delta item and return true.
void	setClosed(boolean value) Set has DeltaStream.close been called?
void	setDeltaItem(java.lang.Object value) Set the current delta item (an EntityValue or ChangedLink), or null.
void	setDeltaLink(java.lang.String value) Set the delta-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.
void	setNextLink(java.lang.String value) Set the next-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.
void	setReadLink(java.lang.String value) Set the read-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.
java.lang.String	toString() Convert this data value to a string.

Methods inherited from class com.sap.cloud.server.odata.DataValue

cloneMutable, equals, getTypeCode, hashCode

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DeltaStream

public DeltaStream()

Method Detail

abort

public void abort()

Close this stream and release all associated resources, without checking first that the end of stream has been reached.

See Also:

DeltaStream.close.

close

public void close()

Close this stream and release all associated resources, checking first that the end of stream has been reached. Can safely be called even if the stream was previously closed. If a delta link was encountered before the stream was closed, it will be available via the DeltaStream.deltaLink property only after the stream is closed. If a next link was encountered before the stream was closed, it will be available via the DeltaStream.nextLink property only after the stream is closed.

See Also:

DeltaStream.abort.

getCurrent

public java.lang.Object getCurrent()

Return (nullable) the current delta item (an EntityValue or ChangedLink), or null if there is no current delta item.

See Also:

DeltaStream.hasCurrent.

Returns:

(nullable) the current delta item (an EntityValue or ChangedLink), or `null` if there is no current delta item.

getDataType

public DataType getDataType()

Return data type with a DataType.code of DataType.DELTA_STREAM.

Specified by:

getDataType in class DataValue

Returns:

Data type with a DataType.code of DataType.DELTA_STREAM.

getDeltaItem

public java.lang.Object getDeltaItem()

Return (nullable) The current delta item (an EntityValue or ChangedLink), or null.

Returns:

(nullable) The current delta item (an EntityValue or ChangedLink), or null.

getDeltaLink

public java.lang.String getDeltaLink()

Return (nullable) The delta-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

Returns:

(nullable) The delta-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

getEntity

public EntityValue getEntity()

Return the current entity value.

Throws:

UsageException if there no current delta item or if the current delta item is a changed link.

See Also:

DeltaStream.getCurrent.

Returns:

the current entity value.

getLink

public ChangedLink getLink()

Return the current changed link.

Throws:

UsageException if there is no current delta item or if the current delta item is an entity value.

See Also:

DeltaStream.getCurrent.

Returns:

the current changed link.

getNextLink

public java.lang.String getNextLink()

Return (nullable) The next-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

Returns:

(nullable) The next-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

getReadLink

public java.lang.String getReadLink()

Return (nullable) The read-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

Returns:

(nullable) The read-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

hasCurrent

public boolean hasCurrent()

Return true if the if the stream has a current delta item (the most recent call to DeltaStream.next returned true and DeltaStream.close has not been called)).

See Also:

DeltaStream.getCurrent.

Returns:

`true` if the if the stream has a current delta item (the most recent call to DeltaStream.next returned `true` and DeltaStream.close has not been called)).

hasEntity

public boolean hasEntity()

Check if the stream has a current delta item which is an entity value.

See Also:

DeltaStream.getEntity.

Returns:

`true` if DeltaStream.hasCurrent would return `true` if called, and the current delta item is an entity value.

hasLink

public boolean hasLink()

Check if the stream has a current delta item which is a changed link.

See Also:

DeltaStream.getLink.

Returns:

`true` if DeltaStream.hasCurrent would return `true` if called, and the current delta item is a changed link.

isClosed

public boolean isClosed()

Return has DeltaStream.close been called?

Returns:

Has DeltaStream.close been called?

next

public abstract boolean next()

If this stream has not been DeltaStream.close and has a next delta item, then advance to the next delta item and return true. Otherwise return false.

See Also:

DeltaStream.hasCurrent, DeltaStream.hasEntity, DeltaStream.hasLink, DeltaStream.getCurrent, DeltaStream.getEntity, DeltaStream.getLink.

Returns:

`true` if there is a next delta item available.

setClosed

public void setClosed(boolean value)

Set has DeltaStream.close been called?

Parameters:

value - Has DeltaStream.close been called?

setDeltaItem

public void setDeltaItem(java.lang.Object value)

Set the current delta item (an EntityValue or ChangedLink), or null.

Parameters:

value - The current delta item (an EntityValue or ChangedLink), or null.

setDeltaLink

public void setDeltaLink(java.lang.String value)

Set the delta-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

Parameters:

value - The delta-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

setNextLink

public void setNextLink(java.lang.String value)

Set the next-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

Parameters:

value - The next-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

setReadLink

public void setReadLink(java.lang.String value)

Set the read-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

Parameters:

value - The read-link (if any) that was encountered when DeltaStream.next was called repeatedly until it returned false and then DeltaStream.close was called, otherwise null.

toString

public java.lang.String toString()

Convert this data value to a string. If the DeltaStream.dataType is defined by XML Schema Part 2: Datatypes, then the corresponding lexical format is used. JSON format is used for structured values (arrays and objects).

Specified by:

toString in class DataValue

Returns:

Lexical representation of this data value.