Custom JSON data to be parse into objects - json

Question

i have this task to parse json data to object, as in
{
"AAA" : {
"A1" : "a1 comment",
"A2" : "a2 comment"
},
"BBB" : {
"B1" : "b1 comment"
},
"CCC" : {
"C1" : "c1 comment",
"C2" : "c2 comment",
"C3" : "c3 comment"
"C4" : "c4 cooment"
},
"DDD" : {
"D1" : "d1 comment"
}
}
need to be converted to objects like ,
class Schema {
String tableName;
List<Column> colData;
And
class Column {
String columnName;
String columnComments;
Since i am a beginner to json, i took to the approach of first parsing things to xml and if it works proceed to parsing xml to object.
but i am having trouble parsing the json data.
however if i replace all the single quotes with double quotes and and '=>' with ':' and only consider AAA, i am able to parse with below code, but if i use the whole json data it throws error.
any help is deeply appreciated.
the code that i have so far is :
FileInputStream fis = new FileInputStream(new File("schema.sql"));
Transformer transformer = TransformerFactory.newInstance().newTransformer();
InputSource source = new InputSource(new StringReader(IOUtils.toString(fis, "UTF-8")));
DOMResult result = new DOMResult();
transformer.transform(new SAXSource(new JsonXmlReader("Table"), source), result);
Node n=result.getNode();
System.out.println(result.toString());
StringWriter writer = new StringWriter();
// Transformer transformer = TransformerFactory.newInstance().newTransformer();
transformer.transform(new DOMSource(n), new StreamResult(writer));
String xml = writer.toString();
System.out.println(xml);
which works for below data:
{
"AAA" : {
"A1" : "a1 comment",
"A2" : "a2 comment"
}
}
ofcourse i had to replace all ' with " and => with :
for the json data
{
"AAA" : {
"A1" : "a1 comment",
"A2" : "a2 comment"
},
"BBB" : {
"B1" : "b1 comment"
}
}
the error that i see is :
ERROR: 'Parsing error: HIERARCHY_REQUEST_ERR: An attempt was made to insert a node where it is not permitted. '
javax.xml.transform.TransformerException: net.javacrumbs.json2xml.JsonSaxAdapter$ParserException: Parsing error: HIERARCHY_REQUEST_ERR: An attempt was made to insert a node where it is not permitted.
at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(Unknown Source)
net.javacrumbs.json2xml.JsonSaxAdapter$ParserException: Parsing error: HIERARCHY_REQUEST_ERR: An attempt was made to insert a node where it is not permitted.
at net.javacrumbs.json2xml.JsonSaxAdapter.parse(JsonSaxAdapter.java:177)
at net.javacrumbs.json2xml.JsonXmlReader.parse(JsonXmlReader.java:152)