FasterXML/jackson-databind · error · IllegalArgumentException

Cannot set maxSerializerCacheSize to a negative value

Error message

Cannot set maxSerializerCacheSize to a negative value

What it means

Thrown by DefaultCacheProvider.Builder.maxSerializerCacheSize(int) when the argument is negative. The serializer cache is a bounded LookupCache; a negative size is meaningless. Zero disables caching; negative is rejected as a programming error.

Solutions

1. Pass a non-negative integer: 0 to disable, positive to set the cap.
2. Clamp external config: Math.max(0, configuredValue).
3. Omit the call entirely if you want the default cache size.

Example fix

// before
DefaultCacheProvider.builder().maxSerializerCacheSize(configuredSize); // throws if -1
// after
DefaultCacheProvider.builder().maxSerializerCacheSize(Math.max(0, configuredSize));

// Validate before passing to builder
if (serCacheSize < 0) {
    throw new IllegalArgumentException("serCacheSize must be >= 0, got: " + serCacheSize);
}
DefaultCacheProvider.builder().maxSerializerCacheSize(serCacheSize);

boolean isValidCacheSize(int size) {
    return size >= 0;
}

When it happens

Trigger: Calling DefaultCacheProvider.builder().maxSerializerCacheSize(-1) or passing a negative value derived from an external configuration or arithmetic error.

Common situations: External configuration with a sentinel -1 default. Arithmetic underflow in computed cache sizes. Copy-paste of a value that was valid for a different API.

Related errors

• Cannot set maxDeserializerCacheSize to a negative value
• Cannot set maxTypeFactoryCacheSize to a negative value
• AnnotationIntrospector.
• AnnotationIntrospector returned `Class<
• AnnotationIntrospector returned Class

AI-assisted analysis of FasterXML/jackson-databind@87876ca5c0 (2026-08-11). Data as JSON: /api/errors/23a634e6ac77f50f. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/tools/jackson/databind/cfg/DefaultCacheProvider.java:184

                throw new IllegalArgumentException("Cannot set maxDeserializerCacheSize to a negative value");
            }
            _maxDeserializerCacheSize = maxDeserializerCacheSize;
            return this;
        }

        /**
         * Define the maximum size of the {@link LookupCache} instance constructed by {@link #forSerializerCache(SerializationConfig)}
         * and {@link #_buildCache(int)}
         * <p>
         * Note that specifying a maximum size of zero prevents values from being retained in the cache.
         *
         * @param maxSerializerCacheSize Size for the {@link LookupCache} to use within {@link SerializerCache}
         * @return this builder
         * @throws IllegalArgumentException if {@code maxSerializerCacheSize} is negative
         */
        public Builder maxSerializerCacheSize(int maxSerializerCacheSize) {
            if (maxSerializerCacheSize < 0) {
                throw new IllegalArgumentException("Cannot set maxSerializerCacheSize to a negative value");
            }
            _maxSerializerCacheSize = maxSerializerCacheSize;
            return this;
        }

        /**
         * Define the maximum size of the {@link LookupCache} instance constructed by {@link #forTypeFactory()}
         * and {@link #_buildCache(int)}
         * <p>
         * Note that specifying a maximum size of zero prevents values from being retained in the cache.
         *
         * @param maxTypeFactoryCacheSize Size for the {@link LookupCache} to use within {@link tools.jackson.databind.type.TypeFactory}
         * @return this builder
         * @throws IllegalArgumentException if {@code maxTypeFactoryCacheSize} is negative
         */
        public Builder maxTypeFactoryCacheSize(int maxTypeFactoryCacheSize) {
            if (maxTypeFactoryCacheSize < 0) {
                throw new IllegalArgumentException("Cannot set maxTypeFactoryCacheSize to a negative value");

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