Can't find a codec for class org.json.JSONArray

You don't have to use JSONObject/JSONArray for conversion.

Replace with below line if the payload.get("data") is Map

BasicDBObject json = new BasicDBObject(payload.get("data"));

Replace with below line if the payload.get("data") holds json string.

BasicDBObject json =(BasicDBObject) JSON.parse(payload.get("data"));

Here's an example of MongoDB from MongoDB University course with a MongoDB database named "students" with a collection named "grades" :

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.mongodb</groupId>
    <artifactId>test</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>test</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.mongodb</groupId>
            <artifactId>mongodb-driver</artifactId>
            <version>3.2.2</version>
        </dependency>
    </dependencies>
</project>

com/mongo/Main.java

package com.mongo;

import com.mongodb.MongoClient;
import com.mongodb.client.*;
import org.bson.Document;
import org.bson.conversions.Bson;

import javax.print.Doc;

public class Main {

    public static void main(String[] args) {

        MongoClient client = new MongoClient();
        MongoDatabase database = client.getDatabase("students");
        final MongoCollection<Document> collection = database.getCollection("grades");

        Bson sort = new Document("student_id", 1).append("score", 1);
        MongoCursor<Document> cursor = collection.find().sort(sort).iterator();

        try {
            Integer student_id = -1;
            while (cursor.hasNext()) {
                Document document = cursor.next();
                // Doing more stuff
            }
        } finally {
            cursor.close();
        }
    }
}