qdrant

SKILL.md

Qdrant Vector Database Integration

Overview

Qdrant is an AI-native vector database for semantic search and similarity retrieval. This skill provides patterns for integrating Qdrant with Java applications, focusing on Spring Boot and LangChain4j integration.

When to Use

Semantic search or recommendation systems in Spring Boot applications

RAG pipelines with Java and LangChain4j

Vector database integration for AI/ML applications

High-performance similarity search with filtered queries

Instructions

1. Deploy Qdrant with Docker
docker run -p 6333:6333 -p 6334:6334 \
    -v "$(pwd)/qdrant_storage:/qdrant/storage:z" \
    qdrant/qdrant

Access: REST API at http://localhost:6333, gRPC at http://localhost:6334.

2. Add Dependencies

Maven:

<dependency>
    <groupId>io.qdrant</groupId>
    <artifactId>client</artifactId>
    <version>1.15.0</version>
</dependency>

Gradle:

implementation 'io.qdrant:client:1.15.0'

3. Initialize Client

QdrantClient client = new QdrantClient(
    QdrantGrpcClient.newBuilder("localhost").build());

For production with API key:

QdrantClient client = new QdrantClient(
    QdrantGrpcClient.newBuilder("localhost", 6334, false)
        .withApiKey("YOUR_API_KEY")
        .build());

4. Create Collection

client.createCollectionAsync("search-collection",
    VectorParams.newBuilder()
        .setDistance(Distance.Cosine)
        .setSize(384)
        .build()
).get();

Validation: Verify the collection was created by checking client.getCollectionAsync("search-collection").get().

5. Upsert Vectors

List<PointStruct> points = List.of(
    PointStruct.newBuilder()
        .setId(id(1))
        .setVectors(vectors(0.05f, 0.61f, 0.76f, 0.74f))
        .putAllPayload(Map.of("title", value("Spring Boot Documentation")))
        .build()
);
client.upsertAsync("search-collection", points).get();

Validation: Check that client.upsertAsync(...).get() completes without throwing.

6. Search Vectors

List<ScoredPoint> results = client.queryAsync(
    QueryPoints.newBuilder()
        .setCollectionName("search-collection")
        .setLimit(5)
        .setQuery(nearest(0.2f, 0.1f, 0.9f, 0.7f))
        .build()
).get();

Filtered search:

List<ScoredPoint> results = client.searchAsync(
    SearchPoints.newBuilder()
        .setCollectionName("search-collection")
        .addAllVector(List.of(0.62f, 0.12f, 0.53f, 0.12f))
        .setFilter(Filter.newBuilder()
            .addMust(range("category", Range.newBuilder().setEq("docs").build()))
            .build())
        .setLimit(5)
        .build()).get();

LangChain4j Integration

For RAG pipelines, use LangChain4j's high-level abstractions:

EmbeddingStore<TextSegment> embeddingStore = QdrantEmbeddingStore.builder()
    .collectionName("rag-collection")
    .host("localhost")
    .port(6334)
    .apiKey("YOUR_API_KEY")
    .build();

Spring Boot configuration with LangChain4j:

@Bean
public EmbeddingStore<TextSegment> embeddingStore() {
    return QdrantEmbeddingStore.builder()
        .collectionName("rag-collection")
        .host(host)
        .port(port)
        .build();
}

@Bean
public EmbeddingModel embeddingModel() {
    return new AllMiniLmL6V2EmbeddingModel();
}

Spring Boot Integration

Inject the client via configuration:

@Configuration
public class QdrantConfig {
    @Value("${qdrant.host:localhost}")
    private String host;

    @Value("${qdrant.port:6334}")
    private int port;

    @Bean
    public QdrantClient qdrantClient() {
        return new QdrantClient(
            QdrantGrpcClient.newBuilder(host, port, false).build());
    }
}

Examples

REST Search Endpoint

@RestController
@RequestMapping("/api/search")
public class SearchController {
    private final VectorSearchService searchService;

    public SearchController(VectorSearchService searchService) {
        this.searchService = searchService;
    }

    @GetMapping
    public List<ScoredPoint> search(@RequestParam String query) {
        List<Float> queryVector = embeddingModel.embed(query).content().vectorAsList();
        return searchService.search("documents", queryVector);
    }
}

Best Practices

Distance metric: Cosine for normalized text embeddings, Euclidean for non-normalized.

Batch upserts: Use batch operations over individual point insertions.

Connection pooling: Configure connection pooling for high-throughput production workloads.

Error handling: Wrap async operations in try/catch for ExecutionException/InterruptedException.

API keys: Store in environment variables or Spring config, never hardcode.

Advanced Patterns

Multi-tenant Storage

public void upsertForTenant(String tenantId, List<PointStruct> points) {
    String collectionName = "tenant_" + tenantId + "_documents";
    client.upsertAsync(collectionName, points).get();
}

Docker Compose for Production

services:
  qdrant:
    image: qdrant/qdrant:v1.7.0
    ports:
      - "6333:6333"
      - "6334:6334"
    volumes:
      - qdrant_storage:/qdrant/storage

References

Qdrant API Reference — Complete client API documentation

Complete Spring Boot Examples — Full application implementations

Qdrant Documentation

LangChain4j Documentation

Constraints and Warnings

Vector dimensions must match the embedding model exactly; mismatched dimensions cause upsert errors.

Input validation: Sanitize all document content before ingestion; untrusted payloads may contain prompt injection attacks.

Content filtering: Apply content filtering on retrieved documents before passing them to the LLM.

Large collections require proper indexing for acceptable search performance.

Use gRPC API (port 6334) for production; REST API (port 6333) for debugging only.

Collection recreation deletes all data; implement backup strategies for production environments.

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