Java: How to log raw JSON as JSON and avoid escaping during logging with logback / slf4j

Question

I\'m using SLF4J with Logback in a JAX-RS application... I want to log to JSON in such a way that my message is not encoded again but printed raw into the logfile:

At t

Answer 1

I can't see the original code that's causing your problem, but I suspect it might look like this

JsonNode logOutput;
String messageJSONAsString;

...

logOutput.put("@message", messageJSONAsString);
logger.info(objectMapper.writeValueAsString(logOutput);

This will produce escaped JSON in your output because when you put the message into the output JsonNode, Jackson will re-escape it for you to make sure the output is valid JSON.

The solution here is to put the message in your output as an ObjectNode rather than as a string. Usually you already have access to the object as an Object, in which case you can do

ObjectNode jsonObject = objectMapper.valueToTree(messageObject);
logOutput.put("@message", jsonObject)

Otherwise, if your message is a JSON string, then parse it and add it to the output

logoutput.put("@message", objectMapper.readTree(messageJSONAsString));