Class KeysAndAttributes
- All Implemented Interfaces:
Serializable
,Cloneable
Represents a set of primary keys and, for each key, the attributes to retrieve from the table.
For each primary key, you must provide all of the key attributes. For example, with a simple primary key, you only need to provide the partition key. For a composite primary key, you must provide both the partition key and the sort key.
- See Also:
-
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionaddExpressionAttributeNamesEntry
(String key, String value) Removes all the entries added into ExpressionAttributeNames.clone()
boolean
One or more attributes to retrieve from the table or index.The consistency of a read operation.One or more substitution tokens for attribute names in an expression.getKeys()
The primary key attribute values that define the items and the attributes associated with the items.A string that identifies one or more attributes to retrieve from the table.int
hashCode()
The consistency of a read operation.void
setAttributesToGet
(Collection<String> attributesToGet) One or more attributes to retrieve from the table or index.void
setConsistentRead
(Boolean consistentRead) The consistency of a read operation.void
setExpressionAttributeNames
(Map<String, String> expressionAttributeNames) One or more substitution tokens for attribute names in an expression.void
setKeys
(Collection<Map<String, AttributeValue>> keys) The primary key attribute values that define the items and the attributes associated with the items.void
setProjectionExpression
(String projectionExpression) A string that identifies one or more attributes to retrieve from the table.toString()
Returns a string representation of this object; useful for testing and debugging.withAttributesToGet
(String... attributesToGet) One or more attributes to retrieve from the table or index.withAttributesToGet
(Collection<String> attributesToGet) One or more attributes to retrieve from the table or index.withConsistentRead
(Boolean consistentRead) The consistency of a read operation.withExpressionAttributeNames
(Map<String, String> expressionAttributeNames) One or more substitution tokens for attribute names in an expression.withKeys
(Collection<Map<String, AttributeValue>> keys) The primary key attribute values that define the items and the attributes associated with the items.withKeys
(Map<String, AttributeValue>... keys) The primary key attribute values that define the items and the attributes associated with the items.withProjectionExpression
(String projectionExpression) A string that identifies one or more attributes to retrieve from the table.
-
Constructor Details
-
KeysAndAttributes
public KeysAndAttributes()
-
-
Method Details
-
getKeys
The primary key attribute values that define the items and the attributes associated with the items.
- Returns:
- The primary key attribute values that define the items and the attributes associated with the items.
-
setKeys
The primary key attribute values that define the items and the attributes associated with the items.
- Parameters:
keys
- The primary key attribute values that define the items and the attributes associated with the items.
-
withKeys
The primary key attribute values that define the items and the attributes associated with the items.
NOTE: This method appends the values to the existing list (if any). Use
setKeys(java.util.Collection)
orwithKeys(java.util.Collection)
if you want to override the existing values.- Parameters:
keys
- The primary key attribute values that define the items and the attributes associated with the items.- Returns:
- Returns a reference to this object so that method calls can be chained together.
-
withKeys
The primary key attribute values that define the items and the attributes associated with the items.
- Parameters:
keys
- The primary key attribute values that define the items and the attributes associated with the items.- Returns:
- Returns a reference to this object so that method calls can be chained together.
-
getAttributesToGet
One or more attributes to retrieve from the table or index. If no attribute names are specified then all attributes will be returned. If any of the specified attributes are not found, they will not appear in the result.
- Returns:
- One or more attributes to retrieve from the table or index. If no attribute names are specified then all attributes will be returned. If any of the specified attributes are not found, they will not appear in the result.
-
setAttributesToGet
One or more attributes to retrieve from the table or index. If no attribute names are specified then all attributes will be returned. If any of the specified attributes are not found, they will not appear in the result.
- Parameters:
attributesToGet
- One or more attributes to retrieve from the table or index. If no attribute names are specified then all attributes will be returned. If any of the specified attributes are not found, they will not appear in the result.
-
withAttributesToGet
One or more attributes to retrieve from the table or index. If no attribute names are specified then all attributes will be returned. If any of the specified attributes are not found, they will not appear in the result.
NOTE: This method appends the values to the existing list (if any). Use
setAttributesToGet(java.util.Collection)
orwithAttributesToGet(java.util.Collection)
if you want to override the existing values.- Parameters:
attributesToGet
- One or more attributes to retrieve from the table or index. If no attribute names are specified then all attributes will be returned. If any of the specified attributes are not found, they will not appear in the result.- Returns:
- Returns a reference to this object so that method calls can be chained together.
-
withAttributesToGet
One or more attributes to retrieve from the table or index. If no attribute names are specified then all attributes will be returned. If any of the specified attributes are not found, they will not appear in the result.
- Parameters:
attributesToGet
- One or more attributes to retrieve from the table or index. If no attribute names are specified then all attributes will be returned. If any of the specified attributes are not found, they will not appear in the result.- Returns:
- Returns a reference to this object so that method calls can be chained together.
-
setConsistentRead
The consistency of a read operation. If set to
true
, then a strongly consistent read is used; otherwise, an eventually consistent read is used.- Parameters:
consistentRead
- The consistency of a read operation. If set totrue
, then a strongly consistent read is used; otherwise, an eventually consistent read is used.
-
getConsistentRead
The consistency of a read operation. If set to
true
, then a strongly consistent read is used; otherwise, an eventually consistent read is used.- Returns:
- The consistency of a read operation. If set to
true
, then a strongly consistent read is used; otherwise, an eventually consistent read is used.
-
withConsistentRead
The consistency of a read operation. If set to
true
, then a strongly consistent read is used; otherwise, an eventually consistent read is used.- Parameters:
consistentRead
- The consistency of a read operation. If set totrue
, then a strongly consistent read is used; otherwise, an eventually consistent read is used.- Returns:
- Returns a reference to this object so that method calls can be chained together.
-
isConsistentRead
The consistency of a read operation. If set to
true
, then a strongly consistent read is used; otherwise, an eventually consistent read is used.- Returns:
- The consistency of a read operation. If set to
true
, then a strongly consistent read is used; otherwise, an eventually consistent read is used.
-
setProjectionExpression
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 ProjectionExpression must be separated by commas.
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.
For more information, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
ProjectionExpression replaces the legacy AttributesToGet parameter.
- Parameters:
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 ProjectionExpression must be separated by commas.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.
For more information, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
ProjectionExpression replaces the legacy AttributesToGet parameter.
-
getProjectionExpression
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 ProjectionExpression must be separated by commas.
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.
For more information, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
ProjectionExpression replaces the legacy AttributesToGet parameter.
- 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
ProjectionExpression must be separated by commas.
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.
For more information, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
ProjectionExpression replaces the legacy AttributesToGet parameter.
-
withProjectionExpression
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 ProjectionExpression must be separated by commas.
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.
For more information, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
ProjectionExpression replaces the legacy AttributesToGet parameter.
- Parameters:
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 ProjectionExpression must be separated by commas.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.
For more information, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
ProjectionExpression replaces the legacy AttributesToGet parameter.
- Returns:
- Returns a reference to this object so that method calls can be chained together.
-
getExpressionAttributeNames
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 Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
- 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 Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
-
-
-
setExpressionAttributeNames
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 Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
- Parameters:
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 Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
-
-
-
withExpressionAttributeNames
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 Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
- Parameters:
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 Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
-
- Returns:
- Returns a reference to this object so that method calls can be chained together.
-
-
addExpressionAttributeNamesEntry
-
clearExpressionAttributeNamesEntries
Removes all the entries added into ExpressionAttributeNames. <p> Returns a reference to this object so that method calls can be chained together. -
toString
Returns a string representation of this object; useful for testing and debugging. -
equals
-
hashCode
public int hashCode() -
clone
-