Java object to JSON with org.json lib

Question

I have class like this:

public class Class1 {
    private String result;
    private String ip;
    private ArrayList<Class2> alarm;
}

Where Alarm its a class like this:

public class Class2 {
    private String bla;
    private String bla1;
}

Is there easy way to convert instance of Class1 to JSON object with org.json?

Carola

Answer 1

I think the utilizing org.json.lib's JSONObject(Object) constructor is what you're looking for. It will construct a JSONObject from your Java Object based on its getters. You can then use JSONObject#toString to get the actual Json produced.

JSONObject jsonObject = new JSONObject(instanceOfClass1);
String myJson = jsonObject.toString();

Capote

His bean doesn't have any public accessor methods, therefore JSONObject won't be able to get ahold of his properties. – Ludie

That's true. I guess it may have been a poor assumption on my part that they were just left out for the sake of brevity. – Capote

@BuffaloBuffalo, your link is 404. – Injun

Answer 2

While JSONObject is the way to go, you need to follow what its JavaDoc says about bean properties:

Construct a JSONObject from an Object using bean getters. It reflects on all of the public methods of the object. For each of the methods with no parameters and a name starting with "get" or "is" followed by an uppercase letter, the method is invoked, and a key and the value returned from the getter method are put into the new JSONObject. The key is formed by removing the "get" or "is" prefix. If the second remaining character is not upper case, then the first character is converted to lower case. For example, if an object has a method named "getName", and if the result of calling object.getName() is "Larry Fine", then the JSONObject will contain "name": "Larry Fine".

Based on the documentation, it will fail in your case because you don't expose those properties via gettings and setters.

Ludie