Class KeysAndAttributes

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 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 Details

    • KeysAndAttributes

      public KeysAndAttributes()
  • Method Details

    • getKeys

      public List<Map<String,AttributeValue>> 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

      public void setKeys(Collection<Map<String,AttributeValue>> keys)

      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

      public KeysAndAttributes withKeys(Map<String,AttributeValue>... keys)

      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) or withKeys(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

      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.

      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.

      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.

      NOTE: This method appends the values to the existing list (if any). Use setAttributesToGet(java.util.Collection) or withAttributesToGet(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

      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.

      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

      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.
    • 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.
    • 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.

      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:
      Returns a reference to this 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.
    • 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, 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

      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, 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

      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, 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

      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, 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

      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, 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

      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, 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

      public KeysAndAttributes addExpressionAttributeNamesEntry(String key, String value)
    • clearExpressionAttributeNamesEntries

      public KeysAndAttributes clearExpressionAttributeNamesEntries()
      Removes all the entries added into ExpressionAttributeNames. <p> 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:
    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object
    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object
    • clone

      public KeysAndAttributes clone()
      Overrides:
      clone in class Object