SerializeTest.java

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

import org.junit.Test;

import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectWriter;

public class SerializeTest {

    public static class AnArray implements Serializable {
        private static final long serialVersionUID = 1L;
        public double[][][] _elements;

        public AnArray() {
            _elements = null;
        }

        public AnArray(double[][][] elements) {
            _elements = elements;
        }
    }

    @Test
    public void testSerialization()
            throws JsonGenerationException, JsonMappingException, IOException,
            ClassNotFoundException {
        File jsonFile = new File("test.json");
        File objFile = new File("test.obj");

        double[][][] elements = new double[128][256][256];

        for (int i = 0; i < elements.length; i++)
            for (int j = 0; j < elements[0].length; j++)
                for (int k = 0; k < elements[0][0].length; k++)
                    elements[i][j][k] = Math.random();

        AnArray arr = new AnArray(elements);

        long startJson = System.currentTimeMillis();
        ObjectMapper mapper = new ObjectMapper();
        ObjectWriter writer = mapper.writer();
        writer.writeValue(jsonFile, arr);
        long jTime = System.currentTimeMillis() - startJson;

        System.out.println("Write time to JSON: " + jTime / 1000.0);

        long startObj = System.currentTimeMillis();
        FileOutputStream fout = new FileOutputStream(objFile);
        ObjectOutputStream outStream = new ObjectOutputStream(fout);
        outStream.writeObject(arr);
        outStream.close();
        long oTime = System.currentTimeMillis() - startObj;

        System.out.println("Write time to Object: " + oTime / 1000.0);

        long startJsonRead = System.currentTimeMillis();
        AnArray jArr = mapper.readValue(jsonFile, AnArray.class);
        long jReadTime = System.currentTimeMillis() - startJsonRead;

        System.out.println("Read time from JSON: " + jReadTime / 1000.0);

        long startObjRead = System.currentTimeMillis();
        FileInputStream fin = new FileInputStream(objFile);
        ObjectInputStream inStream = new ObjectInputStream(fin);
        AnArray oArr = (AnArray)inStream.readObject();
        inStream.close();
        long oReadTime = System.currentTimeMillis() - startObjRead;

        System.out.println("Read time from Object: " + oReadTime / 1000.0);

        for (int i = 0; i < elements.length; i++) {
            for (int j = 0; j < elements.length; j++) {
                for (int k = 0; k < elements.length; k++) {
                    assert elements[i][j][k] == jArr._elements[i][j][k];
                    assert elements[i][j][k] == oArr._elements[i][j][k];
                }
            }
        }
    }
}