Test.java

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Arrays;
import java.util.HashMap;

import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.FieldSerializerTest.Hello;
import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;
import com.esotericsoftware.kryo.serializers.MapSerializer;

public class Test {
	static class Hello {
		public int size = 100;
		public HashMap<String, String> map = new HashMap<String, String>();

		public Hello() {
			map = new HashMap<String, String>();
			map.put("001", "xxx");
		}
	}

	static void test() {
		Kryo kryo = new Kryo();
		kryo.register(HashMap.class);
		kryo.register(Hello.class);
		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
		Output output = new Output(outStream, 4096);

		Hello hello = new Hello();

		kryo.writeClassAndObject(output, hello);
		output.flush();

		byte[] data = outStream.toByteArray();
		System.out.println(Arrays.toString(data));

		Input input = new Input(new ByteArrayInputStream(data), 4096);

		Hello hello2 = (Hello) kryo.readClassAndObject(input);

		System.out.println(hello2);
	}

	public static void main(String[] args) {
		test();
	}
}

The code can work with Kryo 2.12 but not Kryo 2.14...