Pretty Print JSON with Java
Note: This has been adapted from steps from mkyong.com.
When we want to pretty print a JSON object in Java, we can take advantage of the Jackson library's serialisation of objects.
For this to happen, all we need is to have a Plain Old Java Object (POJO) that is the data object for the class, with the relevant markup for JSON properties:
import com.fasterxml.jackson.annotation.JsonProperty;
class TheObject {
@JsonProperty("wibble")
public String wibble;
@JsonProperty("foo")
public int foo;
}
Now we can use an instance of Jackson's ObjectMapper class to return a String with the pretty-printed JSON value, which we can then print out as we want:
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
public void prettyPrintObject() {
ObjectMapper objectMapper = new ObjectMapper();
TheObject o = new TheObject();
o.wibble = "hello there";
o.foo = 1234;
o.map = new HashMap<>();
o.map.put("abc", "def");
String value = objectMapper.writerWithDefaultPrettyPrinter()
.writeValueAsString(o);
System.out.println(value);
}
This gives us a nice pretty-printed result:
{
"wibble" : "hello there",
"foo" : 1234,
"map" : {
"abc" : "def"
}
}
This was tested with Jackson v2.9.8.
