public final class FetchOptions
extends java.lang.Object
PreparedQuery
.
limit
is the maximum number of results the query will return.
offset
is the number of results to skip before returning any
results. Results that are skipped due to offset do not count against
limit
.
startCursor
and
endCursor
are previously generated cursors
that point to locations in a result set. If specified queries will start
and end at these locations.
prefetchSize
is the number of results retrieved on the first call
to the datastore.
chunkSize
determines the internal chunking strategy of the
Iterator
returned by
PreparedQuery.asIterator(FetchOptions)
and the
Iterable
returned by
PreparedQuery.asIterable(FetchOptions)
.
Note that unlike
limit
,
offset
and
cursor
,
prefetchSize
and
chunkSize
have no impact on the result of
the
PreparedQuery
, but rather only the performance of the
PreparedQuery
.
Notes on usage:
The recommended way to instantiate a
FetchOptions
object is to
statically import
FetchOptions.Builder
.* and invoke a static
creation method followed by an instance mutator (if needed):
import static com.google.appengine.api.datastore.FetchOptions.Builder.*; ... // limit 10 datastoreService.prepare(query).asList(withLimit(10)); // limit 10, offset 5 datastoreService.prepare(query).asList(withLimit(10).offset(5));
Modifier and Type | Class and Description |
---|---|
static class
|
FetchOptions.Builder
Contains static creation methods for
FetchOptions
.
|
Modifier and Type | Field and Description |
---|---|
static int
|
DEFAULT_CHUNK_SIZE
Deprecated.
Instead of using DEFAULT_CHUNK_SIZE, do not specify a chunk size.
|
Modifier and Type | Method and Description |
---|---|
FetchOptions
|
chunkSize
(int chunkSize)
Sets the chunk size.
|
FetchOptions
|
cursor
(
Cursor
cursor)
Deprecated.
use
startCursor
instead.
|
FetchOptions
|
endCursor
(
Cursor
endCursor)
Sets the cursor at which to end the query.
|
boolean
|
equals
(java.lang.Object obj)
|
java.lang.Integer
|
getChunkSize
()
|
Cursor
|
getCursor
()
Deprecated.
use
getStartCursor()
instead
|
Cursor
|
getEndCursor
()
|
java.lang.Integer
|
getLimit
()
|
java.lang.Integer
|
getOffset
()
|
java.lang.Integer
|
getPrefetchSize
()
|
Cursor
|
getStartCursor
()
|
int
|
hashCode
()
|
FetchOptions
|
limit
(int limit)
Sets the limit.
|
FetchOptions
|
offset
(int offset)
Sets the offset.
|
FetchOptions
|
prefetchSize
(int prefetchSize)
Sets the number of entities to prefetch.
|
FetchOptions
|
startCursor
(
Cursor
startCursor)
Sets the cursor at which to start the query.
|
java.lang.String
|
toString
()
|
@Deprecated public static final int DEFAULT_CHUNK_SIZE
public FetchOptions limit(int limit)
limit
- The limit to set. Must be non-negative.
this
(for chaining)
public FetchOptions offset(int offset)
offset
- The offset to set. Must be 0 or greater.
this
(for chaining)
public FetchOptions chunkSize(int chunkSize)
chunkSize
- The chunk size to set. Must be greater than 0.
this
(for chaining)
public FetchOptions prefetchSize(int prefetchSize)
prefetchSize
- The prefetch size to set. Must be >= 0.
this
(for chaining)
@Deprecated public FetchOptions cursor(Cursor cursor)
startCursor
instead.
cursor
- the cursor to set
this
(for chaining)
public FetchOptions startCursor(Cursor startCursor)
startCursor
- the cursor to set
this
(for chaining)
public FetchOptions endCursor(Cursor endCursor)
endCursor
- the cursor to set
this
(for chaining)
public java.lang.Integer getLimit()
null
if no limit was provided.
public java.lang.Integer getOffset()
null
if no offset was provided.
public java.lang.Integer getChunkSize()
null
if no chunk size was provided.
public java.lang.Integer getPrefetchSize()
null
if no prefetch size was
provided.
@Deprecated public Cursor getCursor()
getStartCursor()
instead
null
if no cursor was provided.
public Cursor getStartCursor()
null
if no start cursor was provided.
public Cursor getEndCursor()
null
if no end cursor was provided.
public int hashCode()
hashCode
in class
java.lang.Object
public boolean equals(java.lang.Object obj)
equals
in class
java.lang.Object
public java.lang.String toString()
toString
in class
java.lang.Object