KeysAndAttributes (AWS Java SDK for Amazon DynamoDB 1.9.24 API)

java.lang.Object
- com.amazonaws.services.dynamodbv2.model.KeysAndAttributes

All Implemented Interfaces:

Serializable, Cloneable
```
public class KeysAndAttributes
extends Object
implements 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 hash type primary key, you only need to provide the hash attribute. For a hash-and-range type primary key, you must provide both the hash attribute and the range attribute.

See Also:
Serialized Form

Constructor Summary

Constructors
Constructor and Description

KeysAndAttributes()

Constructors
Constructor and Description
`KeysAndAttributes()`

Method Summary

Methods
Modifier and Type	Method and Description
`KeysAndAttributes`	`addExpressionAttributeNamesEntry(String key, String value)` One or more substitution tokens for attribute names in an expression.
`KeysAndAttributes`	`clearExpressionAttributeNamesEntries()` Removes all the entries added into ExpressionAttributeNames.
`KeysAndAttributes`	`clone()`
`boolean`	`equals(Object obj)`
`List<String>`	`getAttributesToGet()` One or more attributes to retrieve from the table or index.
`Boolean`	`getConsistentRead()` The consistency of a read operation.
`Map<String,String>`	`getExpressionAttributeNames()` One or more substitution tokens for attribute names in an expression.
`List<Map<String,AttributeValue>>`	`getKeys()` The primary key attribute values that define the items and the attributes associated with the items.
`String`	`getProjectionExpression()` A string that identifies one or more attributes to retrieve from the table.
`int`	`hashCode()`
`Boolean`	`isConsistentRead()` 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.
`String`	`toString()` Returns a string representation of this object; useful for testing and debugging.
`KeysAndAttributes`	`withAttributesToGet(Collection<String> attributesToGet)` One or more attributes to retrieve from the table or index.
`KeysAndAttributes`	`withAttributesToGet(String... attributesToGet)` One or more attributes to retrieve from the table or index.
`KeysAndAttributes`	`withConsistentRead(Boolean consistentRead)` The consistency of a read operation.
`KeysAndAttributes`	`withExpressionAttributeNames(Map<String,String> expressionAttributeNames)` One or more substitution tokens for attribute names in an expression.
`KeysAndAttributes`	`withKeys(Collection<Map<String,AttributeValue>> keys)` The primary key attribute values that define the items and the attributes associated with the items.
`KeysAndAttributes`	`withKeys(Map<String,AttributeValue>... keys)` The primary key attribute values that define the items and the attributes associated with the items.
`KeysAndAttributes`	`withProjectionExpression(String projectionExpression)` A string that identifies one or more attributes to retrieve from the table.

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - KeysAndAttributes
```
public KeysAndAttributes()
```
- Method Detail
  - getKeys
```
public List<Map<String,AttributeValue>> getKeys()
```
    The primary key attribute values that define the items and the attributes associated with the items.
    Constraints:
    Length: 1 - 100
    
    Returns:
    The primary key attribute values that define the items and the attributes associated with the items.
  - setKeys
```
public void setKeys(Collection<Map<String,AttributeValue>> keys)
```
    The primary key attribute values that define the items and the attributes associated with the items.
    Constraints:
    Length: 1 - 100
    
    Parameters:
    keys - The primary key attribute values that define the items and the attributes associated with the items.
  - withKeys
```
public KeysAndAttributes withKeys(Map<String,AttributeValue>... keys)
```
    The primary key attribute values that define the items and the attributes associated with the items.
    Returns a reference to this object so that method calls can be chained together.
    Constraints:
    Length: 1 - 100
    
    Parameters:
    keys - The primary key attribute values that define the items and the attributes associated with the items.
    
    Returns:
    A reference to this updated object so that method calls can be chained together.
  - withKeys
```
public KeysAndAttributes withKeys(Collection<Map<String,AttributeValue>> keys)
```
    The primary key attribute values that define the items and the attributes associated with the items.
    Returns a reference to this object so that method calls can be chained together.
    Constraints:
    Length: 1 - 100
    
    Parameters:
    keys - The primary key attribute values that define the items and the attributes associated with the items.
    
    Returns:
    A reference to this updated object so that method calls can be chained together.
  - getAttributesToGet
```
public List<String> 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.
    Constraints:
    Length: 1 -
    
    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
```
public void setAttributesToGet(Collection<String> 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.
    Constraints:
    Length: 1 -
    
    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
```
public KeysAndAttributes withAttributesToGet(String... 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 a reference to this object so that method calls can be chained together.
    Constraints:
    Length: 1 -
    
    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:
    A reference to this updated object so that method calls can be chained together.
  - withAttributesToGet
```
public KeysAndAttributes withAttributesToGet(Collection<String> 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 a reference to this object so that method calls can be chained together.
    Constraints:
    Length: 1 -
    
    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:
    A reference to this updated object so that method calls can be chained together.
  - isConsistentRead
```
public Boolean 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.
  - setConsistentRead
```
public void setConsistentRead(Boolean consistentRead)
```
    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 to true, then a strongly consistent read is used; otherwise, an eventually consistent read is used.
  - withConsistentRead
```
public KeysAndAttributes withConsistentRead(Boolean consistentRead)
```
    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 a reference to this object so that method calls can be chained together.
    
    Parameters:
    consistentRead - 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:
    A reference to this updated object so that method calls can be chained together.
  - getConsistentRead
```
public Boolean 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.
  - getProjectionExpression
```
public String 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, go to Accessing 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 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, go to Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
  - setProjectionExpression
```
public void setProjectionExpression(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 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, go to Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
    
    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, go to Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
  - withProjectionExpression
```
public KeysAndAttributes withProjectionExpression(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 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, go to Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
    Returns a reference to this object so that method calls can be chained together.
    
    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, go to Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
    
    Returns:
    A reference to this updated object so that method calls can be chained together.
  - getExpressionAttributeNames
```
public Map<String,String> 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, go to 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, go to 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, go to 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, go to Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
  - setExpressionAttributeNames
```
public void setExpressionAttributeNames(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, go to 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, go to 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, go to 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, go to Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
  - withExpressionAttributeNames
```
public KeysAndAttributes withExpressionAttributeNames(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, go to 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, go to Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
    Returns a reference to this object so that method calls can be chained together.
    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, go to 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, go to Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
    Returns:
    A reference to this updated object so that method calls can be chained together.
  - addExpressionAttributeNamesEntry
```
public KeysAndAttributes addExpressionAttributeNamesEntry(String key,
                                                 String value)
```
    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, go to 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, go to Accessing Item Attributes in the Amazon DynamoDB Developer Guide.
    The method adds a new key-value pair into ExpressionAttributeNames parameter, and returns a reference to this object so that method calls can be chained together.
    Parameters:
    key - The key of the entry to be added into ExpressionAttributeNames.
    value - The corresponding value of the entry to be added into ExpressionAttributeNames.
  - clearExpressionAttributeNamesEntries
```
public KeysAndAttributes clearExpressionAttributeNamesEntries()
```
    Removes all the entries added into ExpressionAttributeNames.
    Returns a reference to this object so that method calls can be chained together.
  - toString
```
public String toString()
```
    Returns a string representation of this object; useful for testing and debugging.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    A string representation of this object.
    See Also:
    Object.toString()
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object obj)
```
    Overrides:
    
    equals in class Object
  - clone
```
public KeysAndAttributes clone()
```
    Overrides:
    
    clone in class Object

Class KeysAndAttributes

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

KeysAndAttributes

Method Detail

getKeys

setKeys

withKeys

withKeys

getAttributesToGet

setAttributesToGet

withAttributesToGet

withAttributesToGet

isConsistentRead

setConsistentRead

withConsistentRead

getConsistentRead

getProjectionExpression

setProjectionExpression

withProjectionExpression

getExpressionAttributeNames

setExpressionAttributeNames

withExpressionAttributeNames

addExpressionAttributeNamesEntry

clearExpressionAttributeNamesEntries

toString

hashCode

equals

clone