How to Pretty Print Object in Java using Jackson

Published Jun 2, 2022

How can we pretty print a Java object using Jackson?

Suppose we have a static ObjectMapper available.

public static final ObjectMapper OBJECT_MAPPER;

Using writerWithDefaultPrettyPrinter(), we can construct an ObjectWriter that serializes objects using the pretty printer for indentation.

public static <T> String prettyPrintObject(T obj) {
  try {
    return OBJECT_MAPPER.writerWithDefaultPrettyPrinter().writeValueAsString(obj);
  } catch (JsonProcessingException e1) {
    throw new RuntimeException(e1);
  }
}

Prior to version 2.1, writeValueAsString() could throw an IOException.

In version 2.1, we can just handle JsonProcessingException, which will throw a standard RunTimeException.