testcontainers/testcontainers-java · error · IllegalArgumentException

Collection name must not be empty

Error message

Collection name must not be empty

What it means

SolrContainer.withCollection validates that the collection/core name is non-empty before storing it in the configuration. An empty (or null, via StringUtils.isEmpty) name is rejected with IllegalArgumentException because Solr cannot create a nameless core.

Solutions

  1. Pass a non-empty literal collection name to withCollection.
  2. Check the config source supplying the name and give it a default value.
  3. Validate the name in your test setup before constructing the container.

Example fix

// before
container.withCollection(System.getProperty("solr.collection"));
// after
String collection = System.getProperty("solr.collection", "testcollection");
container.withCollection(collection);
Defensive patterns

Strategy: validation

Validate before calling

if (collection == null || collection.isEmpty()) throw new IllegalArgumentException("Solr collection name must not be empty");
container.withCollection(collection);

Prevention

When it happens

Trigger: Calling withCollection("") or withCollection(null), often when the name comes from an unset config property or environment variable.

Common situations: Collection name read from a properties/YAML file that is missing the key, or built by string concatenation that yields "".

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

AI-assisted analysis of testcontainers/testcontainers-java@8e549514e3 (2026-09-12). Data as JSON: /api/errors/7ad7e776a807cc19. Report an issue: GitHub.

Appendix: source

Thrown at modules/solr/src/main/java/org/testcontainers/solr/SolrContainer.java:63

    public SolrContainer(final DockerImageName dockerImageName) {
        super(dockerImageName);
        dockerImageName.assertCompatibleWith(DEFAULT_IMAGE_NAME);

        waitingFor(
            Wait.forLogMessage(".*o\\.e\\.j\\.s\\.Server Started.*", 1).withStartupTimeout(Duration.ofMinutes(1))
        );
        this.configuration = new SolrContainerConfiguration();
        this.imageVersion = new ComparableVersion(dockerImageName.getVersionPart());
    }

    public SolrContainer withZookeeper(boolean zookeeper) {
        configuration.setZookeeper(zookeeper);
        return self();
    }

    public SolrContainer withCollection(String collection) {
        if (StringUtils.isEmpty(collection)) {
            throw new IllegalArgumentException("Collection name must not be empty");
        }
        configuration.setCollectionName(collection);
        return self();
    }

    public SolrContainer withConfiguration(String name, URL solrConfig) {
        if (StringUtils.isEmpty(name) || solrConfig == null) {
            throw new IllegalArgumentException();
        }
        configuration.setConfigurationName(name);
        configuration.setSolrConfiguration(solrConfig);
        return self();
    }

    public SolrContainer withSchema(URL schema) {
        configuration.setSolrSchema(schema);
        return self();
    }

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