public static void main(String[] args) {
    String[] strings = new String[]{"first", "second"};
    System.out.println(Arrays.toString(strings));
    byte[][] byteStrings = convertToBytes(strings);
    strings = convertToStrings(byteStrings);
    System.out.println(Arrays.toString(strings));

}

private static String[] convertToStrings(byte[][] byteStrings) {
    String[] data = new String[byteStrings.length];
    for (int i = 0; i < byteStrings.length; i++) {
        data[i] = new String(byteStrings[i], Charset.defaultCharset());

    }
    return data;
}


private static byte[][] convertToBytes(String[] strings) {
    byte[][] data = new byte[strings.length][];
    for (int i = 0; i < strings.length; i++) {
        String string = strings[i];
        data[i] = string.getBytes(Charset.defaultCharset()); // you can chose charset
    }
    return data;
}

final String[] stringArray = { "foo", "bar", "baz" };

final ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
final ObjectOutputStream objectOutputStream =
    new ObjectOutputStream(byteArrayOutputStream);
objectOutputStream.writeObject(stringArray);
objectOutputStream.flush();
objectOutputStream.close();

final byte[] byteArray = byteArrayOutputStream.toByteArray();

final ByteArrayInputStream byteArrayInputStream =
    new ByteArrayInputStream(byteArray);
final ObjectInputStream objectInputStream =
    new ObjectInputStream(byteArrayInputStream);

final String[] stringArray2 = (String[]) objectInputStream.readObject();

objectInputStream.close();

import java.nio.ByteBuffer;
import java.util.ArrayList;

public class Serialization {
    public static byte[] serialize(String[] strs) {
        ArrayList<Byte> byteList = new ArrayList<Byte>();
        for (String str: strs) {
            int len = str.getBytes().length;
            ByteBuffer bb = ByteBuffer.allocate(4);
            bb.putInt(len);
            byte[] lenArray = bb.array();
            for (byte b: lenArray) {
                byteList.add(b);
            }
            byte[] strArray = str.getBytes();
            for (byte b: strArray) {
                byteList.add(b);
            }
        }
        byte[] result = new byte[byteList.size()];
        for (int i=0; i<byteList.size(); i++) {
            result[i] = byteList.get(i);
        }
        return result;
    }

    public static String[] unserialize(byte[] bytes) {
        ArrayList<String> strList = new ArrayList<String>();
        for (int i=0; i< bytes.length;) {
            byte[] lenArray = new byte[4];
            for (int j=i; j<i+4; j++) {
                lenArray[j-i] = bytes[j];
            }
            ByteBuffer wrapped = ByteBuffer.wrap(lenArray);
            int len = wrapped.getInt();
            byte[] strArray = new byte[len];
            for (int k=i+4; k<i+4+len; k++) {
                strArray[k-i-4] = bytes[k];
            }
            strList.add(new String(strArray));
            i += 4+len;
        }
        return strList.toArray(new String[strList.size()]);
    }

    public static void main(String[] args) {
        String[] input = {"This is","a serialization problem;","string concatenation will do as well","in some cases."};
        byte[] byteArray = serialize(input);
        String[] output = unserialize(byteArray);
        for (String str: output) {
            System.out.println(str);
        }
    }
}

public class Concatenation {
    public static byte[] concatenate(String[] strs) {
        StringBuilder sb = new StringBuilder();
        for (int i=0; i<strs.length; i++) {
            sb.append(strs[i]);
            if (i != strs.length-1) {
                sb.append("*.*"); //concatenate by this splitter
            }
        }
        return sb.toString().getBytes();
    }

    public static String[] split(byte[] bytes) {
        String entire = new String(bytes);
        return entire.split("\*\.\*");
    }

    public static void main(String[] args) {
        String[] input = {"This is","a serialization problem;","string concatenation will do as well","in some cases."};
        byte[] byteArray = concatenate(input);
        String[] output = split(byteArray);
        for (String str: output) {
            System.out.println(str);
        }
    }
}