json-path/JsonPath · error · UnsupportedOperationException

Json-smart provider does not support TypeRef! Use a Jackson

Error message

Json-smart provider does not support TypeRef! Use a Jackson or Gson based provider

What it means

JsonSmartMappingProvider cannot perform generic TypeRef-based conversions; its map(Object, TypeRef<T>, Configuration) implementation always throws UnsupportedOperationException. Generic databind needs Jackson or Gson, as the message states.

Source

Thrown at json-path/src/main/java/com/jayway/jsonpath/spi/mapper/JsonSmartMappingProvider.java:94

        }
        if (targetType.isAssignableFrom(source.getClass())) {
            return (T) source;
        }
        try {
            if(!configuration.jsonProvider().isMap(source) && !configuration.jsonProvider().isArray(source)){
                return factory.call().getMapper(targetType).convert(source);
            }
            String s = configuration.jsonProvider().toJson(source);
            return (T) JSONValue.parse(s, targetType);
        } catch (Exception e) {
            throw new MappingException(e);
        }

    }

    @Override
    public <T> T map(Object source, TypeRef<T> targetType, Configuration configuration) {
        throw new UnsupportedOperationException("Json-smart provider does not support TypeRef! Use a Jackson or Gson based provider");
    }

    private static class StringReader extends JsonReaderI<String> {
        public StringReader() {
            super(null);
        }
        public String convert(Object src) {
            if(src == null){
                return null;
            }
            return src.toString();
        }
    }
    private static class IntegerReader extends JsonReaderI<Integer> {
        public IntegerReader() {
            super(null);
        }
        public Integer convert(Object src) {

View on GitHub (pinned to 62a4c9f0f6)

Solutions

1. Configure JacksonMappingProvider or GsonMappingProvider: Configuration.builder().mappingProvider(new JacksonMappingProvider()).build()
2. Replace the TypeRef read with a plain class read or manual conversion from JSONObject/JSONArray
3. Pass an explicit Configuration via JsonPath.using(config) instead of relying on defaults

Example fix

// before
List<MyDto> list = JsonPath.parse(json).read("$[*]", new TypeRef<List<MyDto>>(){}); // JsonSmart
// after
Configuration cfg = Configuration.builder()
    .mappingProvider(new GsonMappingProvider()).build();
List<MyDto> list = JsonPath.using(cfg).parse(json).read("$[*]", new TypeRef<List<MyDto>>(){});

// verify TypeRef capability before typed reads
if (config.getMappingProvider() instanceof JsonSmartMappingProvider) {
    throw new IllegalStateException("Use Jackson/Gson mapping provider for TypeRef reads");
}

boolean supportsTypeRef(Configuration cfg) {
    return !(cfg.getMappingProvider() instanceof JsonSmartMappingProvider);
}

try {
    T v = JsonPath.using(config).parse(json).read(path, new TypeRef<T>(){});
} catch (UnsupportedOperationException e) {
    // JsonSmart cannot databind: reconfigure to Jackson/Gson or use Class-based read
}

When it happens

Trigger: Calling read(path, TypeRef<T>) (e.g. new TypeRef<Map<String,Object>>(){}) while the configuration's mapping provider is JsonSmartMappingProvider (json-smart based, including net.minidev defaults).

Common situations: Relying on JsonSmart defaults (it's a common default provider in json-path) and then requesting typed reads; migrating code from a Jackson-configured project to one configured with json-smart; frameworks that set the smart provider via ServiceLoader discovery.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• JsonOrg provider does not support TypeRef! Use a Jackson or
• Tapestry JSON provider does not support TypeRef! Use a Jacks
• Put can not be performed to multiple properties
• Rename can not be performed to multiple properties
• setProperty operation cannot be used with

AI-assisted analysis of json-path/JsonPath@62a4c9f0f6 (2026-09-11). Data as JSON: /api/errors/15491073d8905f16. Report an issue: GitHub.