Create and read tree data structure from json string dynamically

Question

I'm trying to develop a dynamic query builder for days. But I'm having a problem with building it.

What I'm reviving is a json like this.

{"category":"Case Law","query":{"AND":{"Year":{"having":"","exact":"","any":"","none":""},"AND":{"Report":{"having":"","exact":"","any":"","none":""},"Citation":{"having":"","exact":"","any":"","none":""}}}}}

Here is it in much readable way

Array
(
    [category] => Case Law
    [query] => Array
        (
            [OR] => Array
                (
                    [Year] => Array
                        (
                            [having] => some
                            [exact] => values
                            [any] => might
                            [none] => have
                        )

                    [AND] => Array
                        (
                            [Report] => Array
                                (
                                    [having] => 
                                    [exact] => 
                                    [any] => 
                                    [none] => 
                                )

                            [Citation] => Array
                                (
                                    [having] => 
                                    [exact] => 
                                    [any] => 
                                    [none] => 
                                )

                        )

                )

        )

)

• this json can change according to the user inputs(can have more depth or less).
• what I'm trying to do is create a search query for apache lucene...(for the moment lets assume that leaf values are just strings.)

It must be something like this(What I need)

(Year:another values OR (Report:some valeus AND Citation:some valeues))

I tried with Jettison library and used DefaultMutableTreeNode to create the tree structure . But it didn't work as I expected.Then i tried whit recursive functions and it also didn't worked

I want to is it possible to create this kind of thing. If yes how to do.

Your attempt is highly appreciated! Thanks in advance.

Answer 1

The JSON String for you query

Ok. This is what i tried.

(Year:another values OR (Report:some valeus AND Citation:some valeues AND Field: another))

should be something like :

String json = 
{"lhs":{"lhs":{"lhs":{"lhs":"Field","rhs":"Value","operator":"EQUAL_TO"},"rhs":{"lhs":"Citation","rhs":"Citation","operator":"EQUAL_TO"},"operator":"AND"},"rhs":{"lhs":"Report","rhs":"Report1","operator":"EQUAL_TO"},"operator":"AND"},"rhs":{"lhs":"Year","rhs":"2001","operator":"EQUAL_TO"},"operator":"OR"}

if The MYOperator enum is :

public enum MyOperator {

    AND,
    OR,
    EQUAL_TO {
    @Override
    public String toString() {
        return ":";
    }
},
    IN

}

and AtomicOperation Is

public class AtomicOperation {


     Object lhs;
     Object rhs;
     MyOperator operator;

     AtomicOperation(Object lhs,MyOperator operator, Object rhs) {
         this.lhs = lhs;
         this.rhs = rhs;
         this.operator = operator;
     }

    public Object getLhs() {
        return lhs;
    }
    public void setLhs(Object lhs) {
        this.lhs = lhs;
    }
    public Object getRhs() {
        return rhs;
    }
    public void setRhs(Object rhs) {
        this.rhs = rhs;
    }
    public MyOperator getOperator() {
        return operator;
    }
    public void setOperator(MyOperator operator) {
        this.operator = operator;
    }

     @Override
public String toString() {
        return "(" + lhs.toString() + " " + operator.toString() + " " + rhs.toString() + ")"; 
}

}

Then You can Build the necessary AtomicOperation Object using the below code

AtomicOperation _r = deriveFromJSON(ConvertJsonToObject.getFromJSON(json,AtomicOperation.class));

Below is the complete ConvertJsonToObject class

public class ConvertJsonToObject {

    private static Gson gson = new GsonBuilder().create();

    public static final <T> T getFromJSON(String json, Class<T> clazz) {
        return gson.fromJson(json, clazz);
    }

    public static final <T> String toJSON(T clazz) {
        return gson.toJson(clazz);
    }
}