This is what i wrote to validate json to the given schema.

public void validateJsonSchema(ObjectNode jsonSchema, ObjectNode json) throws InvalidRequestException {      String errorMessage = null;      if (json != null) {          if(jsonSchema == null) {             errorMessage = "json exist in request but there is no schema to validate it against";         }          try {             JsonSchema jsonSchema = JsonSchemaFactory.byDefault().getJsonSchema(jsonSchema);             ProcessingReport processingReport = jsonSchema.validate(json);              if (!processingReport.isSuccess()) {                  StringBuilder sb = new StringBuilder();                 processingReport.forEach(jsonError -> sb.append(String.format("[%s] ", jsonError)));                  errorMessage = String.format("json validation failed. Errors: %s", sb.toString());             }          } catch (ProcessingException e) {             errorMessage = String.format("json validation threw ProcessingException. Error Message: %s", e.getMessage());         }     }      if (errorMessage != null) {         throw new InvalidRequestException(errorMessage);     }  } 

Here are few things that i had in my mind while writing this code

1. I don’t want to return anything from the method. Schema is either valid or invalid. In case of invalid, i just throw an exception. Since its part of a Helper class, i think its okay to put some business logc (throwing exception) with in this code.

2. I like 1 point of return or 1 point of exception throwing. Thats why i am using errorMessage to capture any error and if it exists, throw it at the end. By this approach, the code readability is much better.

3. The jsonSchema and json both could are optional. In case if json doesn’t exist, there is no point of getting into validation.