TreeMap的排序

import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;

import org.apache.commons.lang3.RandomUtils;
import org.junit.Test;

public class MapUtils {

    @Test
    public void testMap() throws Exception {
        Map<String, Object> hashMap = new HashMap<String, Object>();
        
        Map<String, Object> map = new TreeMap<String, Object>(new Comparator<String>() {
            @Override
            public int compare(String o1, String o2) {
                return o1.compareTo(o2);
            }
        });

        for (int i = 0; i < 10; i++) {
            map.put("20170" + i + RandomUtils.nextInt(1, 30), i);
        }

        for (Map.Entry<String, Object> entryt : map.entrySet()) {
            System.out.println(entryt.getKey() + "=" + entryt.getValue());
        }
    }

}
TreeMap自定义Comparator排序