JsonSchemaFactory jsonSchemaFactory = JsonSchemaFactory.getInstance(SpecVersion.VersionFlag.V202012);

    SchemaValidatorsConfig schemaValidatorsConfig = new SchemaValidatorsConfig ();

    //schemaValidatorsConfig.setFailFast(true);
    schemaValidatorsConfig.setHandleNullableField(true);
    schemaValidatorsConfig.setTypeLoose(false);

    //build json schema node
    JsonNode schemaNode;
    try {
        schemaNode = objectMapper.valueToTree(schema);
        
    } catch (Exception e) {
        
    }
    
    //build input json node
    JsonNode jsonNode;
    try {
        jsonNode = objectMapper.readTree(json);
    } catch (IOException e) {
        
    }
    
    //validate the json with the schema
    Set<ValidationMessage> validationErrors;
    
    JsonSchema jsonSchema = jsonSchemaFactory.getSchema(schemaNode, schemaValidatorsConfig);
    
    validationErrors = jsonSchema.validate(jsonNode);

Disclaimer: I contribute to this project.

While this library does not currently support severities, you can fake it with a few changes. First update your schema to preface each message with your desired severity.

"zip_code": {
  "type": "string",
  "minLength": 1,
  "message": {
    "type": "ERROR: Address.zip_code is not a 'String' value",
    "minLength": "ERROR: Address.zip_code is empty"
  }
}

Second, update your code to test for the prefix.

InputStream inputStream = ExampleClass.class.getClassLoader().getResourceAsStream(schema);
JsonSchemaFactory factory = JsonSchemaFactory.getInstance(SpecVersion.VersionFlag.V202012);
JsonSchema jsonSchema = factory.getSchema(inputStream);

Set<ValidationMessage> errors = jsonSchema.validate(event);
errors.forEach(validationMessage -> {
    if(validationMessage.getDetails().startsWith("ERROR: ")) {
       log.error(validationMessage.getDetails().substring("ERROR: ".length()));
    } else {
       log.warn(validationMessage.getDetails());
    }
});