Class ExpandingQueryTransformer

java.lang.Object

dev.langchain4j.rag.query.transformer.ExpandingQueryTransformer

All Implemented Interfaces:

QueryTransformer

public class ExpandingQueryTransformer
extends Object
implements QueryTransformer

A QueryTransformer that utilizes a ChatModel to expand a given Query.
Refer to DEFAULT_PROMPT_TEMPLATE and implementation for more details.

Configurable parameters (optional):
- promptTemplate: The prompt template used to instruct the LLM to expand the provided Query.
- n: The number of Querys to generate. Default value is 3.

See Also:

• DefaultQueryTransformer
• CompressingQueryTransformer

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ExpandingQueryTransformer.ExpandingQueryTransformerBuilder

Field Summary

Fields

Modifier and Type	Field	Description
protected final ChatModel	chatModel
static final int	DEFAULT_N
static final PromptTemplate	DEFAULT_PROMPT_TEMPLATE
protected final int	n
protected final PromptTemplate	promptTemplate

Constructor Summary

Constructors

Constructor	Description
ExpandingQueryTransformer(ChatModel chatModel)
ExpandingQueryTransformer(ChatModel chatModel, int n)
ExpandingQueryTransformer(ChatModel chatModel, PromptTemplate promptTemplate)
ExpandingQueryTransformer(ChatModel chatModel, PromptTemplate promptTemplate, Integer n)

Method Summary

Modifier and Type	Method	Description
static ExpandingQueryTransformer.ExpandingQueryTransformerBuilder	builder()
protected Prompt	createPrompt(Query query)
protected List<String>	parse(String queries)
Collection<Query>	transform(Query query)	Transforms the given Query into one or multiple Querys.
CompletableFuture<Collection<Query>>	transformAsync(Query query)	Non-blocking counterpart of QueryTransformer.transform(Query), invoked by the asynchronous (CompletableFuture/CompletionStage) and reactive (Flow.Publisher) AI Service modes when RAG is configured.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_PROMPT_TEMPLATE

public static final PromptTemplate DEFAULT_PROMPT_TEMPLATE

DEFAULT_N

public static final int DEFAULT_N

See Also:

• Constant Field Values

chatModel

protected final ChatModel chatModel

promptTemplate

protected final PromptTemplate promptTemplate

n

protected final int n

Constructor Details

ExpandingQueryTransformer

public ExpandingQueryTransformer(ChatModel chatModel)

ExpandingQueryTransformer

public ExpandingQueryTransformer(ChatModel chatModel,
 int n)

ExpandingQueryTransformer

public ExpandingQueryTransformer(ChatModel chatModel,
 PromptTemplate promptTemplate)

ExpandingQueryTransformer

public ExpandingQueryTransformer(ChatModel chatModel,
 PromptTemplate promptTemplate,
 Integer n)

Method Details

builder

public static ExpandingQueryTransformer.ExpandingQueryTransformerBuilder builder()

transform

public Collection<Query> transform(Query query)

Description copied from interface: QueryTransformer

Transforms the given Query into one or multiple Querys.

Specified by:

transform in interface QueryTransformer

Parameters:

query - The Query to be transformed.

Returns:

A collection of one or more Querys derived from the original Query.

transformAsync

public CompletableFuture<Collection<Query>> transformAsync(Query query)

Description copied from interface: QueryTransformer

Non-blocking counterpart of QueryTransformer.transform(Query), invoked by the asynchronous (CompletableFuture/CompletionStage) and reactive (Flow.Publisher) AI Service modes when RAG is configured.

The default implementation returns a failed future carrying AsyncNotSupportedException: a transformer backed by a blocking LLM call (e.g. query compression/expansion) must opt in by overriding this method to stay off the calling thread. A transformer that cannot be made non-blocking is still usable from these modes via DefaultRetrievalAugmentor, which offloads the blocking QueryTransformer.transform(Query) to its executor.

Specified by:

transformAsync in interface QueryTransformer

Parameters:

query - The Query to be transformed.

Returns:

A CompletableFuture of one or more Querys derived from the original Query.

createPrompt

protected Prompt createPrompt(Query query)

parse

protected List<String> parse(String queries)