{"record":{"id":"4bcbbf227cf24087","repo":"FasterXML/jackson-databind","slug":"cannot-use-formatschema-of-type-for-format","errorCode":null,"errorMessage":"Cannot use FormatSchema of type {} for format {}","messagePattern":"Cannot use FormatSchema of type (.+?) for format (.+?)","errorType":"exception","errorClass":"IllegalArgumentException","httpStatus":null,"severity":"error","filePath":"src/main/java/tools/jackson/databind/ObjectReader.java","lineNumber":2093,"sourceCode":"                if (_valueToUpdate != null) {\n                    bt = _valueToUpdate.getClass();\n                }\n            }\n            ctxt.reportTrailingTokens(bt, p, t);\n        }\n    }\n\n    /*\n    /**********************************************************************\n    /* Internal methods, other\n    /**********************************************************************\n     */\n\n    protected void _verifySchemaType(FormatSchema schema)\n    {\n        if (schema != null) {\n            if (!_parserFactory.canUseSchema(schema)) {\n                    throw new IllegalArgumentException(\"Cannot use FormatSchema of type \"+schema.getClass().getName()\n                            +\" for format \"+_parserFactory.getFormatName());\n            }\n        }\n    }\n\n    /**\n     * Internal helper method called to create an instance of {@link DeserializationContext}\n     * for deserializing a single root value.\n     * Can be overridden if a custom context is needed.\n     */\n    protected DeserializationContextExt _deserializationContext() {\n        return _contexts.createContext(_config, _schema, _injectableValues);\n    }\n\n    protected DeserializationContextExt _deserializationContext(JsonParser p) {\n        return _contexts.createContext(_config, _schema, _injectableValues)\n                .assignParser(p);\n    }","sourceCodeStart":2075,"sourceCodeEnd":2111,"githubUrl":"https://github.com/FasterXML/jackson-databind/blob/87876ca5c0569b4933aec2d30d6225e4b9ba3a43/src/main/java/tools/jackson/databind/ObjectReader.java#L2075-L2111","documentation":"Thrown by ObjectReader._verifySchemaType() when a FormatSchema is set on the reader but the underlying parser factory cannot use it. Each format (JSON, CSV, YAML, XML, etc.) has its own schema type (e.g., CsvSchema); passing a schema from a different format is a type mismatch. The check uses the factory's canUseSchema() method.","triggerScenarios":"Calling reader.with(schema) where schema is, e.g., a CsvSchema but the reader is backed by a JsonFactory. Also happens when a module registers a format factory but the wrong schema type is supplied, or when mixing format-specific readers without checking.","commonSituations":"Using a base ObjectMapper (JSON) and attempting to apply a YAML or CSV schema. Copy-pasting schema configuration from one format's code to another. Module ordering issues where a format-specific mapper is overridden by the default JSON factory.","solutions":["Ensure the schema type matches the reader's format: use the format-specific mapper (e.g., CsvMapper for CsvSchema, YAMLMapper for YAML schema).","Check factory.canUseSchema(schema) before calling with(schema) if the format is dynamic.","Verify you are using the correct mapper subclass: new CsvMapper().readerFor(type).with(csvSchema)."],"exampleFix":"// before\nObjectReader r = jsonMapper.readerFor(MyType.class).with(csvSchema); // throws: JSON factory can't use CSV schema\n// after\nObjectReader r = csvMapper.readerFor(MyType.class).with(csvSchema);","handlingStrategy":"validation","validationCode":"// Check schema compatibility before setting\nif (schema != null && !reader._parserFactory.canUseSchema(schema)) {\n    throw new IllegalArgumentException(\"Schema \" + schema.getClass() + \" incompatible with format \"\n        + reader._parserFactory.getFormatName());\n}","typeGuard":"boolean schemaMatchesFactory(JsonFactory factory, FormatSchema schema) {\n    return schema == null || factory.canUseSchema(schema);\n}","tryCatchPattern":null,"preventionTips":["Use the format-specific mapper (CsvMapper, YAMLMapper) that matches your schema.","Never mix schemas across formats.","Verify getFormatName() of your factory before applying a schema."],"tags":["format-schema","objectreader","format-mismatch","csv","yaml","configuration"],"backgroundTag":null,"analyzedSha":"87876ca5c0569b4933aec2d30d6225e4b9ba3a43","analyzedAt":"2026-08-11T12:55:24.033Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}