JSON - Convert Object to JSON Array

Question

i try to convert a class object which are generated via Reflection and convert them to JSON string. following is my methods

public Object creatObjectAsString(String className) {
    Object objects = null;
    try {
        objects = java.lang.reflect.Array.newInstance( Class.forName(className), 1);
        //System.out.println(objects.toString());
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }
    return objects ;
}
public String convertPlainObjectToJSON( Object obj,boolean isArray){
    String jsonString="",tempJSON="";
    JSONSerializer serializer = new JSONSerializer();
    tempJSON = serializer.serialize(obj);
    if(isArray){
        jsonString="["+tempJSON+"]";
    }else{
        jsonString=tempJSON;
    }
    return jsonString;
}

I have hard coded the following lines since i did not know how to create JSON Array which is not the correct way of programming.

if(isArray){
    jsonString="["+tempJSON+"]";
}else{
    jsonString=tempJSON;
}

when i printed the convertPlainObjectToJSON result of method i get the following [[null]] which is not expected.

what is the mistake i make.

Please correct me.

I have also seen that but my case is different where i create object using Reflection and convert the object to JSON or JSON Array. — Java Questions
– Java Questions, Commented Apr 29, 2013 at 7:16
if you notice your output, u can see [[ double square braces, which means the JSONSerializer has already converted it to an JSONArray. You needn't do it manually. And regd the null, make sure that your obj passed to the method convertPlainObjectToJSON is not null. — Rahul
– Rahul, Commented Apr 29, 2013 at 7:19
yes, the object i pass is null, because i just want to pass the empty json string/Array — Java Questions
– Java Questions, Commented Apr 29, 2013 at 7:26
An empty array is something different from null. You can e.g. create one using new Object[0]. @R.J, your comment seems like it would make a good answer, do you want to post it as such? — MvG
– MvG, Commented Apr 29, 2013 at 10:15

MvG · Accepted Answer · 2013-04-29 10:48:24Z

1

If you notice your output, you can see [[ (double square braces), which means the JSONSerializer has already converted it to an JSONArray. Therefore, you needn't do it again manually.

And regarding the null between them, it is because you're passing null to the convertPlainObjectToJSON. Send a newly created object array (as @MvG mentioned), new Object[0], and you'll get what you want!

Always remember that blank and null are not the same!

edited Apr 29, 2013 at 10:48

MvG

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answered Apr 29, 2013 at 10:21

Rahul

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