JSON serialization of Java's ResultSet returned by DataStax Java Driver

output.txt

>mvn exec:java -Dexec.mainClass="com.datastax.alexott.demos.jdtest1.Test1"
[{"id": "e7ae5cf3-d358-4d99-b900-85902fda9bb1", "b": true, "i": 1, "t": "test 1"},{"id": "e7ae5cf3-d358-4d99-b900-85902fda9bb3", "b": false, "i": 3, "t": null},{"id": "e7ae5cf3-d358-4d99-b900-85902fda9bb2", "b": false, "i": 10, "t": "test 5"}]
[{"id":"e7ae5cf3-d358-4d99-b900-85902fda9bb1","b":true,"i":1,"t":"test 1"},{"id":"e7ae5cf3-d358-4d99-b900-85902fda9bb3","b":false,"i":3,"t":null},{"id":"e7ae5cf3-d358-4d99-b900-85902fda9bb2","b":false,"i":10,"t":"test 5"}]

ResultSetSerializer.java

package com.datastax.alexott.demos.jdtest1;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.datastax.driver.core.ColumnDefinitions;
import com.datastax.driver.core.DataType;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Row;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.ser.std.StdSerializer;

@SuppressWarnings("serial")
public class ResultSetSerializer extends StdSerializer<ResultSet> {
	public ResultSetSerializer() {
		this(null);
	}

	public ResultSetSerializer(Class<ResultSet> t) {
		super(t);
	}

	void writeItem(Row row, int i, String name, DataType dt, JsonGenerator jgen) throws IOException {
		if (DataType.cboolean().equals(dt)) {
			jgen.writeBooleanField(name, row.getBool(i));
		} else if(DataType.cint().equals(dt)) {
			jgen.writeNumberField(name, row.getInt(i));
		} else {
			jgen.writeStringField(name, row.getObject(i).toString());
		}
	}

	@Override
	public void serialize(ResultSet rs, JsonGenerator jgen, SerializerProvider provider) throws IOException {
		ColumnDefinitions cd = rs.getColumnDefinitions();
		List<ColumnDefinitions.Definition> lcd = cd.asList();
		int lsize = lcd.size();
		String[] names = new String[lsize];
		DataType[] types = new DataType[lsize];
		for (int i = 0; i < lsize; i++) {
			ColumnDefinitions.Definition cdef = lcd.get(i);
			names[i] = cdef.getName();
			types[i] = cdef.getType();
		}

		jgen.writeStartArray();
		for (Row row : rs) {
			jgen.writeStartObject();
			for (int i = 0; i < lsize; i++) {
				String name = names[i];
				if (row.isNull(i)) {
					jgen.writeNullField(name);
				} else {
					writeItem(row, i, name, types[i], jgen);
				}
			}
			jgen.writeEndObject();
		}
		jgen.writeEndArray();
	}

}

table.cql

CREATE TABLE test.jtest (
    id uuid PRIMARY KEY,
    b boolean,
    i int,
    t text
);

Test1.java

package com.datastax.alexott.demos.jdtest1;

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Row;
import com.datastax.driver.core.Session;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;

public class Test1 {
	public static void main(String[] args) throws JsonProcessingException {
		Cluster cluster = Cluster.builder().addContactPoint("127.0.0.1").build();
		Session session = cluster.connect();

		ResultSet rs = session.execute("select json * from test.jtest ;");
		int i = 0;
		System.out.print("[");
		for (Row row : rs) {
			if (i > 0)
				System.out.print(",");
			i++;
			String json = row.getString(0);
			System.out.print(json);
		}
		System.out.println("]");

		ObjectMapper mapper = new ObjectMapper();
		SimpleModule module = new SimpleModule();
		module.addSerializer(ResultSet.class, new ResultSetSerializer());
		mapper.registerModule(module);

		rs = session.execute("select * from test.jtest ;");
		String json = mapper.writeValueAsString(rs);
		System.out.println(json);

		session.close();
		cluster.close();
	}

}