Class DataFetchersDelegateCharacterImpl
java.lang.Object
org.starwars.server.datafetchersdelegate.DataFetchersDelegateCharacterImpl
- All Implemented Interfaces:
DataFetchersDelegateCharacter
@Component
public class DataFetchersDelegateCharacterImpl
extends Object
implements DataFetchersDelegateCharacter
- Author:
- etienne-sf
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Field Summary
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionThis method loads the data for Character.appearsIn.batchLoader
(List<UUID> keys) This method loads a list of ${dataFetcher.field.name}, based on the list of id to be fetched.This method loads the data for Character.friends.Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface org.starwars.server.util.DataFetchersDelegateCharacter
unorderedReturnBatchLoader
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Field Details
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logger
protected org.slf4j.Logger loggerThe logger for this instance
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Constructor Details
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DataFetchersDelegateCharacterImpl
public DataFetchersDelegateCharacterImpl()
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Method Details
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friends
public List<Character> friends(graphql.schema.DataFetchingEnvironment dataFetchingEnvironment, Character source) Description copied from interface:DataFetchersDelegateCharacter
This method loads the data for Character.friends.- Specified by:
friends
in interfaceDataFetchersDelegateCharacter
- Parameters:
dataFetchingEnvironment
- The GraphQLDataFetchingEnvironment
. It gives you access to the full GraphQL context for this DataFetchersource
- The object from which the field is fetch. In other word: the aim of this data fetcher is to fetch the friends attribute of the origin, which is an instance of {InterfaceType {name:Character, fields:{Field{name:id, type:ID!, params:[]},Field{name:name, type:String!, params:[]},Field{name:friends, type:[Character], params:[]},Field{name:appearsIn, type:[Episode]!, params:[]}}, comments ""}. It depends on your data modle, but it typically contains the id to use in the query.
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appearsIn
public List<Episode> appearsIn(graphql.schema.DataFetchingEnvironment dataFetchingEnvironment, Character source) Description copied from interface:DataFetchersDelegateCharacter
This method loads the data for Character.appearsIn.- Specified by:
appearsIn
in interfaceDataFetchersDelegateCharacter
- Parameters:
dataFetchingEnvironment
- The GraphQLDataFetchingEnvironment
. It gives you access to the full GraphQL context for this DataFetchersource
- The object from which the field is fetch. In other word: the aim of this data fetcher is to fetch the appearsIn attribute of the origin, which is an instance of {InterfaceType {name:Character, fields:{Field{name:id, type:ID!, params:[]},Field{name:name, type:String!, params:[]},Field{name:friends, type:[Character], params:[]},Field{name:appearsIn, type:[Episode]!, params:[]}}, comments ""}. It depends on your data modle, but it typically contains the id to use in the query.
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batchLoader
Description copied from interface:DataFetchersDelegateCharacter
This method loads a list of ${dataFetcher.field.name}, based on the list of id to be fetched. This method is used by graphql-java java-dataloader to highly optimize the number of requests to the server, when recursing down through the object associations.
You can find more information on this page: graphql-java batching
Important notes:- The list returned by this method must be sorted in the exact same order as the given keys list. If values are missing (no value for a given key), then the returned list must contain a null value at this key's position.
- One of
batchLoader
orunorderedReturnBatchLoader
must be overriden in the data fetcher implementation. If not, then a NullPointerException will be thrown at runtime, with a proper error message. - If your data storage implementation makes it complex to return values in the same order as the keys list, then it's
easier to override
unorderedReturnBatchLoader
, and let the default implementation ofbatchLoader
order the values
- Specified by:
batchLoader
in interfaceDataFetchersDelegateCharacter
- Parameters:
keys
- A list of ID's id, for which the matching objects must be returned- Returns:
- A list of IDs
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