@Generated(value="software.amazon.awssdk:codegen") public final class GetItemRequest extends DynamoDbRequest implements ToCopyableBuilder<GetItemRequest.Builder,GetItemRequest>
Represents the input of a GetItem
operation.
Modifier and Type | Class and Description |
---|---|
static interface |
GetItemRequest.Builder |
Modifier and Type | Method and Description |
---|---|
List<String> |
attributesToGet()
This is a legacy parameter.
|
static GetItemRequest.Builder |
builder() |
Boolean |
consistentRead()
Determines the read consistency model: If set to
true , then the operation uses strongly consistent
reads; otherwise, the operation uses eventually consistent reads. |
boolean |
equals(Object obj) |
boolean |
equalsBySdkFields(Object obj) |
Map<String,String> |
expressionAttributeNames()
One or more substitution tokens for attribute names in an expression.
|
<T> Optional<T> |
getValueForField(String fieldName,
Class<T> clazz) |
boolean |
hasAttributesToGet()
For responses, this returns true if the service returned a value for the AttributesToGet property.
|
boolean |
hasExpressionAttributeNames()
For responses, this returns true if the service returned a value for the ExpressionAttributeNames property.
|
int |
hashCode() |
boolean |
hasKey()
For responses, this returns true if the service returned a value for the Key property.
|
Map<String,AttributeValue> |
key()
A map of attribute names to
AttributeValue objects, representing the primary key of the item to
retrieve. |
String |
projectionExpression()
A string that identifies one or more attributes to retrieve from the table.
|
ReturnConsumedCapacity |
returnConsumedCapacity()
Returns the value of the ReturnConsumedCapacity property for this object.
|
String |
returnConsumedCapacityAsString()
Returns the value of the ReturnConsumedCapacity property for this object.
|
List<SdkField<?>> |
sdkFields() |
static Class<? extends GetItemRequest.Builder> |
serializableBuilderClass() |
String |
tableName()
The name of the table containing the requested item.
|
GetItemRequest.Builder |
toBuilder() |
String |
toString()
Returns a string representation of this object.
|
overrideConfiguration
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
copy
public final String tableName()
The name of the table containing the requested item.
public final boolean hasKey()
isEmpty()
method on the property). This is useful
because the SDK will never return a null collection or map, but you may need to differentiate between the service
returning nothing (or null) and the service returning an empty collection or map. For requests, this returns true
if a value for the property was specified in the request builder, and false if a value was not specified.public final Map<String,AttributeValue> key()
A map of attribute names to AttributeValue
objects, representing the primary key of the item to
retrieve.
For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.
Attempts to modify the collection returned by this method will result in an UnsupportedOperationException.
This method will never return null. If you would like to know whether the service returned this field (so that
you can differentiate between null and empty), you can use the hasKey()
method.
AttributeValue
objects, representing the primary key of the item
to retrieve.
For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.
public final boolean hasAttributesToGet()
isEmpty()
method on the property).
This is useful because the SDK will never return a null collection or map, but you may need to differentiate
between the service returning nothing (or null) and the service returning an empty collection or map. For
requests, this returns true if a value for the property was specified in the request builder, and false if a
value was not specified.public final List<String> attributesToGet()
This is a legacy parameter. Use ProjectionExpression
instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.
Attempts to modify the collection returned by this method will result in an UnsupportedOperationException.
This method will never return null. If you would like to know whether the service returned this field (so that
you can differentiate between null and empty), you can use the hasAttributesToGet()
method.
ProjectionExpression
instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.public final Boolean consistentRead()
Determines the read consistency model: If set to true
, then the operation uses strongly consistent
reads; otherwise, the operation uses eventually consistent reads.
true
, then the operation uses strongly
consistent reads; otherwise, the operation uses eventually consistent reads.public final ReturnConsumedCapacity returnConsumedCapacity()
If the service returns an enum value that is not available in the current SDK version,
returnConsumedCapacity
will return ReturnConsumedCapacity.UNKNOWN_TO_SDK_VERSION
. The raw value
returned by the service is available from returnConsumedCapacityAsString()
.
ReturnConsumedCapacity
public final String returnConsumedCapacityAsString()
If the service returns an enum value that is not available in the current SDK version,
returnConsumedCapacity
will return ReturnConsumedCapacity.UNKNOWN_TO_SDK_VERSION
. The raw value
returned by the service is available from returnConsumedCapacityAsString()
.
ReturnConsumedCapacity
public final String projectionExpression()
A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.
If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.
For more information, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.
If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.
For more information, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.
public final boolean hasExpressionAttributeNames()
isEmpty()
method on the
property). This is useful because the SDK will never return a null collection or map, but you may need to
differentiate between the service returning nothing (or null) and the service returning an empty collection or
map. For requests, this returns true if a value for the property was specified in the request builder, and false
if a value was not specified.public final Map<String,String> expressionAttributeNames()
One or more substitution tokens for attribute names in an expression. The following are some use cases for using
ExpressionAttributeNames
:
To access an attribute whose name conflicts with a DynamoDB reserved word.
To create a placeholder for repeating occurrences of an attribute name in an expression.
To prevent special characters in an attribute name from being misinterpreted in an expression.
Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:
Percentile
The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For
the complete list of reserved words, see Reserved Words in
the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for
ExpressionAttributeNames
:
{"#P":"Percentile"}
You could then use this substitution in an expression, as in this example:
#P = :val
Tokens that begin with the : character are expression attribute values, which are placeholders for the actual value at runtime.
For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.
Attempts to modify the collection returned by this method will result in an UnsupportedOperationException.
This method will never return null. If you would like to know whether the service returned this field (so that
you can differentiate between null and empty), you can use the hasExpressionAttributeNames()
method.
ExpressionAttributeNames
:
To access an attribute whose name conflicts with a DynamoDB reserved word.
To create a placeholder for repeating occurrences of an attribute name in an expression.
To prevent special characters in an attribute name from being misinterpreted in an expression.
Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:
Percentile
The name of this attribute conflicts with a reserved word, so it cannot be used directly in an
expression. (For the complete list of reserved words, see Reserved
Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the
following for ExpressionAttributeNames
:
{"#P":"Percentile"}
You could then use this substitution in an expression, as in this example:
#P = :val
Tokens that begin with the : character are expression attribute values, which are placeholders for the actual value at runtime.
For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.
public GetItemRequest.Builder toBuilder()
toBuilder
in interface ToCopyableBuilder<GetItemRequest.Builder,GetItemRequest>
toBuilder
in class DynamoDbRequest
public static GetItemRequest.Builder builder()
public static Class<? extends GetItemRequest.Builder> serializableBuilderClass()
public final int hashCode()
hashCode
in class AwsRequest
public final boolean equals(Object obj)
equals
in class AwsRequest
public final boolean equalsBySdkFields(Object obj)
equalsBySdkFields
in interface SdkPojo
public final String toString()
public final <T> Optional<T> getValueForField(String fieldName, Class<T> clazz)
getValueForField
in class SdkRequest
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