[JSON] Object <-> JSON

 

출처 - http://www.mkyong.com/java/how-to-enable-pretty-print-json-output-jackson/

It’s easy to enable pretty print JSON output in Jackson framework. Take last object to/from json example :

   User user = new User();
   ObjectMapper mapper = new ObjectMapper();
   System.out.println(mapper.writeValueAsString(user));

It will display JSON in compact mode :

{"age":29,"messages":["msg 1","msg 2","msg 3"],"name":"mkyong"}

To enable pretty print, just call the "defaultPrettyPrintingWriter()” like this :

   User user = new User();
   ObjectMapper mapper = new ObjectMapper();
   System.out.println(mapper.defaultPrettyPrintingWriter().writeValueAsString(user));

Output

{
  "age" : 29,
  "messages" : [ "msg 1", "msg 2", "msg 3" ],
  "name" : "mkyong"
}

See a full example.

package com.mkyong.core;
 
import java.io.IOException;
import org.codehaus.jackson.JsonGenerationException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
 
public class JacksonExample {
  public static void main(String[] args) {
 
	User user = new User();
	ObjectMapper mapper = new ObjectMapper();
 
	try {
 
		System.out.println(mapper.defaultPrettyPrintingWriter()
				         .writeValueAsString(user));
 
	} catch (JsonGenerationException e) {
 
		e.printStackTrace();
 
	} catch (JsonMappingException e) {
 
		e.printStackTrace();
 
	} catch (IOException e) {
 
		e.printStackTrace();
 
	}
 
    }
 
}