Package software.amazon.awssdk.services.dynamodb.model

Class GetItemRequest

    • Method Detail

      • tableName

        public final String tableName()

        The name of the table containing the requested item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.

        Returns:
        The name of the table containing the requested item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.

      • hasKey

        public final boolean hasKey()
        For responses, this returns true if the service returned a value for the Key property. This DOES NOT check that the value is non-empty (for which, you should check the 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.

      • key

        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.

        Returns:
        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.

      • hasAttributesToGet

        public final boolean hasAttributesToGet()
        For responses, this returns true if the service returned a value for the AttributesToGet property. This DOES NOT check that the value is non-empty (for which, you should check the 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.

      • attributesToGet

        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.

        Returns:
        This is a legacy parameter. Use ProjectionExpression instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.

      • consistentRead

        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.

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

      • returnConsumedCapacityAsString

        public final String returnConsumedCapacityAsString()
        Returns the value of the ReturnConsumedCapacity property for this object.

        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().

        Returns:
        The value of the ReturnConsumedCapacity property for this object.
        See Also:
        ReturnConsumedCapacity

      • projectionExpression

        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.

        Returns:
        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.

      • hasExpressionAttributeNames

        public final boolean hasExpressionAttributeNames()
        For responses, this returns true if the service returned a value for the ExpressionAttributeNames property. This DOES NOT check that the value is non-empty (for which, you should check the 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.

      • expressionAttributeNames

        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.

        Returns:
        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.

      • toString

        public final String toString()
        Returns a string representation of this object. This is useful for testing and debugging. Sensitive data will be redacted from this string using a placeholder value.
        Overrides:
        toString in class Object