TableSchema (AWS Java SDK :: DynamoDB :: Enhanced Client 2.17.275 API)

Type Parameters:

T - The type of model object that is being mapped to records in the DynamoDb table.

All Known Implementing Classes:

BeanTableSchema, ImmutableTableSchema, MetaTableSchema, StaticImmutableTableSchema, StaticTableSchema, WrappedTableSchema
```
@ThreadSafe
public interface TableSchema<T>
```
Interface for a mapper that is capable of mapping a modelled Java object into a map of AttributeValue that is understood by the DynamoDb low-level SDK and back again. This object is also expected to know about the structure of the table it is modelling, which is stored in a TableMetadata object.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`List<String>`	`attributeNames()` Returns a complete list of attribute names that are mapped by this `TableSchema`
`AttributeValue`	`attributeValue(T item, String attributeName)` Returns a single attribute value from the modelled object.
`static <T> StaticTableSchema.Builder<T>`	`builder(Class<T> itemClass)` Returns a builder for the `StaticTableSchema` implementation of this interface which allows all attributes, tags and table structure to be directly declared in the builder.
`static <T,B> StaticImmutableTableSchema.Builder<T,B>`	`builder(Class<T> immutableItemClass, Class<B> immutableBuilderClass)` Returns a builder for the `StaticImmutableTableSchema` implementation of this interface which allows all attributes, tags and table structure to be directly declared in the builder.
`default AttributeConverter<T>`	`converterForAttribute(Object key)` `AttributeConverter` that is applied to the given key.
`static <T> BeanTableSchema<T>`	`fromBean(Class<T> beanClass)` Scans a bean class that has been annotated with DynamoDb bean annotations and then returns a `BeanTableSchema` implementation of this interface that can map records to and from items of that bean class.
`static <T> TableSchema<T>`	`fromClass(Class<T> annotatedClass)` Scans a class that has been annotated with DynamoDb enhanced client annotations and then returns an appropriate `TableSchema` implementation that can map records to and from items of that class.
`static <T> ImmutableTableSchema<T>`	`fromImmutableClass(Class<T> immutableClass)` Scans an immutable class that has been annotated with DynamoDb immutable annotations and then returns a `ImmutableTableSchema` implementation of this interface that can map records to and from items of that immutable class.
`boolean`	`isAbstract()` A boolean value that represents whether this `TableSchema` is abstract which means that it cannot be used to directly create records as it is lacking required structural elements to map to a table, such as a primary key, but can be referred to and embedded by other schemata.
`Map<String,AttributeValue>`	`itemToMap(T item, boolean ignoreNulls)` Takes a modelled object and converts it into a raw map of `AttributeValue` that the DynamoDb low-level SDK can work with.
`Map<String,AttributeValue>`	`itemToMap(T item, Collection<String> attributes)` Takes a modelled object and extracts a specific set of attributes which are then returned as a map of `AttributeValue` that the DynamoDb low-level SDK can work with.
`EnhancedType<T>`	`itemType()` Returns the `EnhancedType` that represents the 'Type' of the Java object this table schema object maps to and from.
`T`	`mapToItem(Map<String,AttributeValue> attributeMap)` Takes a raw DynamoDb SDK representation of a record in a table and maps it to a Java object.
`default T`	`mapToItem(Map<String,AttributeValue> attributeMap, boolean preserveEmptyObject)` Takes a raw DynamoDb SDK representation of a record in a table and maps it to a Java object.
`TableMetadata`	`tableMetadata()` Returns the object that describes the structure of the table being modelled by the mapper.

- Method Detail
  - builder
```
static <T> StaticTableSchema.Builder<T> builder(Class<T> itemClass)
```
    Returns a builder for the StaticTableSchema implementation of this interface which allows all attributes, tags and table structure to be directly declared in the builder.
    
    Type Parameters:
    
    T - The type of the item this TableSchema will map records to.
    
    Parameters:
    
    itemClass - The class of the item this TableSchema will map records to.
    
    Returns:
    
    A newly initialized StaticTableSchema.Builder.
  - builder
```
static <T,B> StaticImmutableTableSchema.Builder<T,B> builder(Class<T> immutableItemClass,
                                                             Class<B> immutableBuilderClass)
```
    Returns a builder for the StaticImmutableTableSchema implementation of this interface which allows all attributes, tags and table structure to be directly declared in the builder.
    
    Type Parameters:
    
    T - The type of the immutable item this TableSchema will map records to.
    
    B - The type of the builder used by this TableSchema to construct immutable items with.
    
    Parameters:
    
    immutableItemClass - The class of the immutable item this TableSchema will map records to.
    
    immutableBuilderClass - The class that can be used to construct immutable items this TableSchema maps records to.
    
    Returns:
    
    A newly initialized StaticImmutableTableSchema.Builder
  - fromBean
```
static <T> BeanTableSchema<T> fromBean(Class<T> beanClass)
```
    Scans a bean class that has been annotated with DynamoDb bean annotations and then returns a BeanTableSchema implementation of this interface that can map records to and from items of that bean class. Creating a BeanTableSchema is a moderately expensive operation, and should be performed sparingly. This is usually done once at application startup.
    
    Type Parameters:
    
    T - The type of the item this TableSchema will map records to.
    
    Parameters:
    
    beanClass - The bean class this TableSchema will map records to.
    
    Returns:
    
    An initialized BeanTableSchema.
  - fromImmutableClass
```
static <T> ImmutableTableSchema<T> fromImmutableClass(Class<T> immutableClass)
```
    Scans an immutable class that has been annotated with DynamoDb immutable annotations and then returns a ImmutableTableSchema implementation of this interface that can map records to and from items of that immutable class. Creating a ImmutableTableSchema is a moderately expensive operation, and should be performed sparingly. This is usually done once at application startup.
    
    Type Parameters:
    
    T - The type of the item this TableSchema will map records to.
    
    Parameters:
    
    immutableClass - The immutable class this TableSchema will map records to.
    
    Returns:
    
    An initialized ImmutableTableSchema.
  - fromClass
```
static <T> TableSchema<T> fromClass(Class<T> annotatedClass)
```
    Scans a class that has been annotated with DynamoDb enhanced client annotations and then returns an appropriate TableSchema implementation that can map records to and from items of that class. Currently supported top level annotations (see documentation on those classes for more information on how to use them):
    DynamoDbBean
    DynamoDbImmutable This is a moderately expensive operation, and should be performed sparingly. This is usually done once at application startup. If this table schema is not behaving as you expect, enable debug logging for 'software.amazon.awssdk.enhanced.dynamodb.beans'.
    
    Type Parameters:
    
    T - The type of the item this TableSchema will map records to.
    
    Parameters:
    
    annotatedClass - A class that has been annotated with DynamoDb enhanced client annotations.
    
    Returns:
    
    An initialized TableSchema
  - mapToItem
```
T mapToItem(Map<String,AttributeValue> attributeMap)
```
    Takes a raw DynamoDb SDK representation of a record in a table and maps it to a Java object. A new object is created to fulfil this operation.
    If attributes are missing from the map, that will not cause an error, however if attributes are found in the map which the mapper does not know how to map, an exception will be thrown.
    If all attribute values in the attributeMap are null, null will be returned. Use mapToItem(Map, boolean) instead if you need to preserve empty object.
    API Implementors Note:
    mapToItem(Map, boolean) must be implemented if preserveEmptyObject behavior is desired.
    
    Parameters:
    
    attributeMap - A map of String to AttributeValue that contains all the raw attributes to map.
    
    Returns:
    
    A new instance of a Java object with all the attributes mapped onto it.
    
    Throws:
    
    IllegalArgumentException - if any attributes in the map could not be mapped onto the new model object.
    
    See Also:
    
    mapToItem(Map, boolean)
  - mapToItem
```
default T mapToItem(Map<String,AttributeValue> attributeMap,
                    boolean preserveEmptyObject)
```
    Takes a raw DynamoDb SDK representation of a record in a table and maps it to a Java object. A new object is created to fulfil this operation.
    If attributes are missing from the map, that will not cause an error, however if attributes are found in the map which the mapper does not know how to map, an exception will be thrown.
    In the scenario where all attribute values in the map are null, it will return null if preserveEmptyObject is true. If it's false, an empty object will be returned.
    Note that preserveEmptyObject only applies to the top level Java object, if it has nested "empty" objects, they will be mapped as null. You can use DynamoDbPreserveEmptyObject to configure this behavior for nested objects.
    API Implementors Note:
    This method must be implemented if preserveEmptyObject behavior is to be supported
    
    Parameters:
    
    attributeMap - A map of String to AttributeValue that contains all the raw attributes to map.
    
    preserveEmptyObject - whether to initialize this Java object as empty class if all fields are null
    
    Returns:
    
    A new instance of a Java object with all the attributes mapped onto it.
    
    Throws:
    
    IllegalArgumentException - if any attributes in the map could not be mapped onto the new model object.
    
    UnsupportedOperationException - if preserveEmptyObject is not supported in the implementation
    
    See Also:
    
    mapToItem(Map)
  - itemToMap
```
Map<String,AttributeValue> itemToMap(T item,
                                     boolean ignoreNulls)
```
    Takes a modelled object and converts it into a raw map of AttributeValue that the DynamoDb low-level SDK can work with.
    
    Parameters:
    
    item - The modelled Java object to convert into a map of attributes.
    
    ignoreNulls - If set to true; any null values in the Java object will not be added to the output map. If set to false; null values in the Java object will be added as AttributeValue of type 'nul' to the output map.
    
    Returns:
    
    A map of String to AttributeValue representing all the modelled attributes in the model object.
  - itemToMap
```
Map<String,AttributeValue> itemToMap(T item,
                                     Collection<String> attributes)
```
    Takes a modelled object and extracts a specific set of attributes which are then returned as a map of AttributeValue that the DynamoDb low-level SDK can work with. This method is typically used to extract just the key attributes of a modelled item and will not ignore nulls on the modelled object.
    
    Parameters:
    
    item - The modelled Java object to extract the map of attributes from.
    
    attributes - A collection of attribute names to extract into the output map.
    
    Returns:
    
    A map of String to AttributeValue representing the requested modelled attributes in the model object.
  - attributeValue
```
AttributeValue attributeValue(T item,
                              String attributeName)
```
    Returns a single attribute value from the modelled object.
    
    Parameters:
    
    item - The modelled Java object to extract the attribute from.
    
    attributeName - The attribute name describing which attribute to extract.
    
    Returns:
    
    A single AttributeValue representing the requested modelled attribute in the model object or null if the attribute has not been set with a value in the modelled object.
  - tableMetadata
```
TableMetadata tableMetadata()
```
    Returns the object that describes the structure of the table being modelled by the mapper. This includes information such as the table name, index keys and attribute tags.
    
    Returns:
    
    A TableMetadata object that contains structural information about the table being modelled.
  - itemType
```
EnhancedType<T> itemType()
```
    Returns the EnhancedType that represents the 'Type' of the Java object this table schema object maps to and from.
    
    Returns:
    
    The EnhancedType of the modelled item this TableSchema maps to.
  - attributeNames
```
List<String> attributeNames()
```
    Returns a complete list of attribute names that are mapped by this TableSchema
  - isAbstract
```
boolean isAbstract()
```
    A boolean value that represents whether this TableSchema is abstract which means that it cannot be used to directly create records as it is lacking required structural elements to map to a table, such as a primary key, but can be referred to and embedded by other schemata.
    
    Returns:
    
    true if it is abstract, and therefore cannot be used directly to create records but can be referred to by other schemata, and false if it is concrete and may be used to map records directly.
  - converterForAttribute
```
default AttributeConverter<T> converterForAttribute(Object key)
```
    AttributeConverter that is applied to the given key.
    
    Parameters:
    
    key - Attribute of the modelled item.
    
    Returns:
    
    AttributeConverter defined for the given attribute key.

Interface TableSchema<T>

Method Summary

Method Detail

builder

builder

fromBean

fromImmutableClass

fromClass

mapToItem

mapToItem

itemToMap

itemToMap

attributeValue

tableMetadata

itemType

attributeNames

isAbstract

converterForAttribute