start = System.currentTimeMillis();
        SerializeUtil.serialize(hmap);
        System.out.println("HashMap serialize:" + (System.currentTimeMillis() - start));

        start = System.currentTimeMillis();
        SerializeUtil.serialize(amap);
        System.out.println("ArrayMap serialize:" + (System.currentTimeMillis() - start));
    }

import java.util.TreeMap;
import java.util.TreeSet;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.core.exception.IORuntimeException;
import org.codelibs.core.io.SerializeUtil;
import org.codelibs.fess.util.ComponentUtil;

import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;