software.amazon.awssdk.enhanced.dynamodb.model

Class ScanEnhancedRequest.Builder

java.lang.Object

software.amazon.awssdk.enhanced.dynamodb.model.ScanEnhancedRequest.Builder

Enclosing class:

ScanEnhancedRequest

@NotThreadSafe
public static final class ScanEnhancedRequest.Builder
extends Object

A builder that is used to create a request with the desired parameters.

Method Summary

Modifier and Type	Method and Description
ScanEnhancedRequest.Builder	addAttributeToProject(String attributeToProject) Adds a single attribute name to be retrieved from the database.
ScanEnhancedRequest.Builder	addNestedAttributesToProject(Collection<NestedAttributeName> nestedAttributeNames) Adds a collection of nested attributes to be retrieved from the database.
ScanEnhancedRequest.Builder	addNestedAttributesToProject(NestedAttributeName... nestedAttributeNames) Adds a collection of nested attributes to be retrieved from the database.
ScanEnhancedRequest.Builder	addNestedAttributeToProject(NestedAttributeName nestedAttributeName) Adds a single nested attribute to be retrieved from the database.
ScanEnhancedRequest.Builder	attributesToProject(Collection<String> attributesToProject) Sets a collection of the attribute names to be retrieved from the database.
ScanEnhancedRequest.Builder	attributesToProject(String... attributesToProject) Sets one or more attribute names to be retrieved from the database.
ScanEnhancedRequest	build()
ScanEnhancedRequest.Builder	consistentRead(Boolean consistentRead) Determines the read consistency model: If set to true, the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.
ScanEnhancedRequest.Builder	exclusiveStartKey(Map<String,AttributeValue> exclusiveStartKey) The primary key of the first item that this operation will evaluate.
ScanEnhancedRequest.Builder	filterExpression(Expression filterExpression) Refines the scan results by applying the filter expression on the results returned from the scan and discards items that do not match.
ScanEnhancedRequest.Builder	limit(Integer limit) Sets a limit on how many items to evaluate in the scan.
ScanEnhancedRequest.Builder	segment(Integer segment) For a parallel Scan request, Segment identifies an individual segment to be scanned by an application worker.
ScanEnhancedRequest.Builder	totalSegments(Integer totalSegments) For a parallel Scan request, TotalSegments represents the total number of segments into which the Scan operation will be divided.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

exclusiveStartKey

public ScanEnhancedRequest.Builder exclusiveStartKey(Map<String,AttributeValue> exclusiveStartKey)

The primary key of the first item that this operation will evaluate. By default, the operation will evaluate the whole dataset. If used, normally this parameter is populated with the value that was returned for Page.lastEvaluatedKey() in the previous operation.

Parameters:

exclusiveStartKey - the primary key value where DynamoDb should start to evaluate items

Returns:

a builder of this type

limit

public ScanEnhancedRequest.Builder limit(Integer limit)

Sets a limit on how many items to evaluate in the scan. If not set, the operation uses the maximum values allowed.

Note:The limit does not refer to the number of items to return, but how many items the database should evaluate while executing the scan. Use limit together with Page.lastEvaluatedKey() and exclusiveStartKey in subsequent scan calls to evaluate limit items per call.

Parameters:

limit - the maximum number of items to evalute

Returns:

a builder of this type

segment

public ScanEnhancedRequest.Builder segment(Integer segment)

For a parallel Scan request, Segment identifies an individual segment to be scanned by an application worker.

Note:Segment IDs are zero-based, so the first segment is always 0. For example, if you want to use four application threads to scan a table or an index, then the first thread specifies a Segment value of 0, the second thread specifies 1, and so on. The value for Segment must be greater than or equal to 0, and less than the value provided for TotalSegments. If you provide Segment, you must also provide TotalSegments.

Parameters:

segment - identifies an individual segment to be scanned

Returns:

a builder of this type

totalSegments

public ScanEnhancedRequest.Builder totalSegments(Integer totalSegments)

For a parallel Scan request, TotalSegments represents the total number of segments into which the Scan operation will be divided.

Note:If you do not specify this value, the TotalSegements is effectively 1 and Scan operation will be sequential rather than parallel. If you specify TotalSegments, you must also specify Segment. If you specify TotalSegments of 2 and above, you can create separate thread for each segment and scan items in parallel across segments from multiple threads.

Parameters:

totalSegments - the total number of segments to divide the table.

Returns:

a builder of this type

consistentRead

public ScanEnhancedRequest.Builder consistentRead(Boolean consistentRead)

Determines the read consistency model: If set to true, the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.

By default, the value of this property is set to false.

Parameters:

consistentRead - sets consistency model of the operation to use strong consistency if true

Returns:

a builder of this type

filterExpression

public ScanEnhancedRequest.Builder filterExpression(Expression filterExpression)

Refines the scan results by applying the filter expression on the results returned from the scan and discards items that do not match. See Expression for examples and constraints.

Note: Using the filter expression does not reduce the cost of the scan, since it is applied after the database has found matching items.

Parameters:

filterExpression - an expression that filters results of evaluating the scan

Returns:

a builder of this type

attributesToProject

public ScanEnhancedRequest.Builder attributesToProject(Collection<String> attributesToProject)

Sets a collection of the attribute names to be retrieved from the database. These attributes can include scalars, sets, or elements of a JSON document.

If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.

If there are nested attributes, use any of the addNestedAttributesToProject methods, such as addNestedAttributesToProject(NestedAttributeName...).

For more information, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide.

Parameters:

attributesToProject - A collection of the attributes names to be retrieved from the database.

Returns:

Returns a reference to this object so that method calls can be chained together.

attributesToProject

public ScanEnhancedRequest.Builder attributesToProject(String... attributesToProject)

Sets one or more attribute names to be retrieved from the database. These attributes can include scalars, sets, or elements of a JSON document.

If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.

If there are nested attributes, use any of the addNestedAttributesToProject methods, such as addNestedAttributesToProject(NestedAttributeName...).

For more information, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide.

Parameters:

attributesToProject - One or more attributes names to be retrieved from the database.

Returns:

Returns a reference to this object so that method calls can be chained together.

addAttributeToProject

public ScanEnhancedRequest.Builder addAttributeToProject(String attributeToProject)

Adds a single attribute name to be retrieved from the database. This attribute can include scalars, sets, or elements of a JSON document.

If there are nested attributes, use any of the addNestedAttributesToProject methods, such as addNestedAttributesToProject(NestedAttributeName...).

Parameters:

attributeToProject - An additional single attribute name to be retrieved from the database.

Returns:

Returns a reference to this object so that method calls can be chained together.

addNestedAttributesToProject

public ScanEnhancedRequest.Builder addNestedAttributesToProject(Collection<NestedAttributeName> nestedAttributeNames)

Adds a collection of nested attributes to be retrieved from the database. These attributes can include scalars, sets, or elements of a JSON document.

This method is additive, so calling it multiple times will add to the list of nested attribute names.

Parameters:

nestedAttributeNames - A collection of attributes to be retrieved from the database.

Returns:

Returns a reference to this object so that method calls can be chained together.

See Also:

NestedAttributeName

addNestedAttributesToProject

public ScanEnhancedRequest.Builder addNestedAttributesToProject(NestedAttributeName... nestedAttributeNames)

Adds a collection of nested attributes to be retrieved from the database. These attributes can include scalars, sets, or elements of a JSON document.

This method is additive, so calling it multiple times will add to the list of nested attribute names.

Parameters:

nestedAttributeNames - A collection of attributes to be retrieved from the database.

Returns:

Returns a reference to this object so that method calls can be chained together.

See Also:

NestedAttributeName

addNestedAttributeToProject

public ScanEnhancedRequest.Builder addNestedAttributeToProject(NestedAttributeName nestedAttributeName)

Adds a single nested attribute to be retrieved from the database. The attribute can include scalars, sets, or elements of a JSON document.

This method is additive, so calling it multiple times will add to the list of nested attribute names.

Parameters:

nestedAttributeName - A single attribute name to be retrieved from the database.

Returns:

Returns a reference to this object so that method calls can be chained together.

See Also:

NestedAttributeName

build

public ScanEnhancedRequest build()