Java Tutorials Corner: JSON Tree Model in Jackson

JSON Tree Model in Jackson

In this Tutorials we are going to see how to read and write JSON Tree model using Jackson JsonNode.
The JsonNode is used to read and write tree structured date.It is similar to XML Dom tree.
1. Create project called JSONExample.
2. Create package called com.javatutorialscorner.jackson
3. add jackson-mapper-asl-1.9.13.jar, jackson-core-asl-1.9.13.jar into build path.
4. Create java class called JacksonTreeExample under com.javatutorialscorner.jackson
JacksonTreeExample.java

package com.javatutorialscorner.jackson;

import java.io.File;
import java.io.IOException;
import java.util.Iterator;

import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.node.ObjectNode;

public class JacksonTreeExample {

 /**
  * @param args
  */
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  ObjectMapper mapper = null;

  mapper = new ObjectMapper();

  try {
   JsonNode root = mapper.readTree(new File(
     "C:\\jtc\\javatutorialscorner.json"));

   JsonNode id = root.path("id");
   System.out.println("ID : " + id.getIntValue());
   JsonNode name = root.path("name");
   System.out.println("Name : " + name.getTextValue());
   JsonNode list = root.path("list");
   Iterator<JsonNode> iterator = list.getElements();
   while (iterator.hasNext()) {
    JsonNode format = iterator.next();
    System.out.println("Format : " + format.getTextValue());
   }

   ((ObjectNode) root).put("id", 7);
   ((ObjectNode) root).put("name", "Dhoni");
   mapper.writeValue(new File("C:\\jtc\\javatutorialscorner.json"),
     root);
  } catch (JsonProcessingException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }

 }

}