Java Tutorials Corner: JSON to Map using Jackson

JSON to Map using Jackson

In this tutorial we are going to see how to convert JSON into Map and retrieve the values
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 JSONToMapExample under com.javatutorialscorner.jackson
JSONToMapExample.java

package com.javatutorialscorner.jackson;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Map;

import org.codehaus.jackson.JsonParseException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.type.TypeReference;

public class JSONToMapExample {

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

  Map<String, Object> map = null;

  ArrayList<String> tutorials = null;

  try {
   mapper = new ObjectMapper();

   map = mapper.readValue(
     new File("C:\\jtc\\javatutorialscorner.json"),
     new TypeReference<Map<String, Object>>() {
     });
   System.out.println("Name : " + map.get("name"));
   System.out.println("Rank : " + map.get("rank"));

   tutorials = (ArrayList<String>) map.get("tutorials");

   for (String tutorial : tutorials) {
    System.out.println("Tutorial : " + tutorial);
   }
  } catch (JsonParseException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (JsonMappingException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }

 }

}

Now run the program see the following output in console.

Name : Java Tutorials Corner

Rank : 1

Tutorial : Java

Tutorial : Servlet

Tutorial : JSP

Tutorial : Struts 1.x

Tutorial : Struts 2.x

Tutorial : Spring

Tutorial : Hibernate

Tutorial : Log4j

Tutorial : JSON

Tutorial : Web Services

Tutorial : JSF

Tutorial : Eclipse