Package org.springframework.graphql.execution

Interface BatchLoaderRegistry

All Superinterfaces:

DataLoaderRegistrar

All Known Implementing Classes:

DefaultBatchLoaderRegistry

public interface BatchLoaderRegistry
extends DataLoaderRegistrar

Registry for functions to batch load data values, given a set of keys.

At request time, each function is registered as a DataLoader in the DataLoaderRegistry and can be accessed in the data layer to load related entities while avoiding the N+1 select problem.

Since:

1.0.0

Author:

Rossen Stoyanchev

See Also:

• Using DataLoader
• BatchLoader
• MappedBatchLoader
• DataLoader

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	BatchLoaderRegistry.RegistrationSpec<K,V>	Spec to complete the registration of a batch loading function.

Method Summary

Modifier and Type	Method	Description
<K, V> BatchLoaderRegistry.RegistrationSpec<K,V>	forName(String name)	Begin the registration of a new batch load function by specifying the name for the DataLoader.
<K, V> BatchLoaderRegistry.RegistrationSpec<K,V>	forTypePair(Class<K> keyType, Class<V> valueType)	Begin the registration of a new batch load function by specifying the types of the keys and values that will be used as input and output.

Methods inherited from interface org.springframework.graphql.execution.DataLoaderRegistrar

hasRegistrations, registerDataLoaders

Method Details

forTypePair

<K,
V> BatchLoaderRegistry.RegistrationSpec<K,V> forTypePair(Class<K> keyType,
 Class<V> valueType)

Begin the registration of a new batch load function by specifying the types of the keys and values that will be used as input and output.

When this method is used, the name for the DataLoader is automatically set as defined in BatchLoaderRegistry.RegistrationSpec.withName(String), and likewise, @SchemaMapping handler methods can transparenly locate and inject a DataLoader<T> argument based on the generic type <T>.

Type Parameters:

K - the key type

V - the value type

Parameters:

keyType - the type of keys that will be used as input

valueType - the type of value that will be returned as output

Returns:

a spec to complete the registration

forName

<K,
V> BatchLoaderRegistry.RegistrationSpec<K,V> forName(String name)

Begin the registration of a new batch load function by specifying the name for the DataLoader.

Note: when this method is used, the parameter name of a DataLoader<T> argument in a @SchemaMapping handler method needs to match the name given here.

Type Parameters:

K - the type of keys that will be used as input

V - the type of values that will be used as output

Parameters:

name - the name to use to register a DataLoader

Returns:

a spec to complete the registration