Wildcard Search in Elasticsearch: Techniques and Java Implementation

Perform Wildcard Search in Elasticsearch

Elasticsearch’s wildcard query enables flexible pattern matching in Java apps. The wildcard query uses * and ? operators for scalable text searches.

Why This Matters

Wildcard queries operate on exact term strings, offering predictable results for keyword fields but sacrificing performance compared to full-text search. Improper use can lead to high memory consumption and slow queries, especially with large datasets. For example, wildcard searches on non-keyword fields may trigger expensive term lookups, increasing latency.

Key Insights

• “Wildcard queries use * and ? for pattern matching (Baeldung, 2025)”
• “Prefix queries optimize left-anchored matching for autocomplete”
• “Elasticsearch’s Java client supports wildcard, prefix, regexp, and fuzzy search methods”

Working Example

SearchResponse<ObjectNode> response = elasticsearchClient.search(s -> s.index(indexName)
    .query(q -> q.wildcard(w -> w.field(fieldName)
        .value(lowercaseSearchTerm)
        .caseInsensitive(true)))
    .size(maxResults), ObjectNode.class);

SearchResponse<ObjectNode> response = elasticsearchClient.search(s -> s.index(indexName)
    .query(q -> q.prefix(p -> p.field(fieldName)
        .value(prefix)))
    .size(maxResults), ObjectNode.class);

SearchResponse<ObjectNode> response = elasticsearchClient.search(s -> s.index(indexName)
    .query(q -> q.regexp(r -> r.field(fieldName)
        .value(pattern)))
    .size(maxResults), ObjectNode.class);

SearchResponse<ObjectNode> response = elasticsearchClient.search(s -> s.index(indexName)
    .query(q -> q.fuzzy(f -> f.field(fieldName)
        .value(searchTerm)
        .fuzziness("AUTO")))
    .size(maxResults), ObjectNode.class);

Practical Applications

• Use Case: E-commerce product search using wildcard for partial matches
• Pitfall: Overusing wildcard queries can lead to high memory usage and slow performance

References:

• https://www.baeldung.com/java-elasticsearch-wildcard

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