How to extract json in groovy

json-slurper.groovy

/*
 * The integration developer needs to create the method processData 
 * This method takes Message object of package com.sap.gateway.ip.core.customdev.util
 * which includes helper methods useful for the content developer:
 * 
 * The methods available are:
    public java.lang.Object getBody()
    
    //This method helps User to retrieve message body as specific type ( InputStream , String , byte[] ) - e.g. message.getBody(java.io.InputStream)
    public java.lang.Object getBody(java.lang.String fullyQualifiedClassName)

    public void setBody(java.lang.Object exchangeBody)

    public java.util.Map<java.lang.String,java.lang.Object> getHeaders()

    public void setHeaders(java.util.Map<java.lang.String,java.lang.Object> exchangeHeaders)

    public void setHeader(java.lang.String name, java.lang.Object value)

    public java.util.Map<java.lang.String,java.lang.Object> getProperties()

    public void setProperties(java.util.Map<java.lang.String,java.lang.Object> exchangeProperties) 

	public void setProperty(java.lang.String name, java.lang.Object value)
 * 
 */
import com.sap.gateway.ip.core.customdev.util.Message;
import groovy.json.*;
import java.lang.String;

def Message processData(Message message) {
	
	def body = message.getBody(java.lang.String) as String;
	def jsonSlurper = new JsonSlurper();
	def jsonDataObject = jsonSlurper.parseText(body);
	//message.setBody(body + "Body is modified");
	
	//Headers 
	//def map = message.getHeaders();
	//def value = map.get("oldHeader");
	//message.setHeader("oldHeader", value + "modified");
	//message.setHeader("Authorization", "newHeader");
	//message.setHeader("newHeader", "newHeader");
	
	//Properties  
	//map = message.getProperties();
	//value = map.get("oldProperty");
	//message.setProperty("oldProperty", value + "modified");
	//message.setProperty("newProperty", "newProperty");
	
	message.setBody(new JsonBuilder(jsonDataObject.args.test).toPrettyString())
	return message;
}