Java | Map排序，工具类改进

package util;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

/***
 *
 * @author YangChaoJie
 *
 */
public class ReqUtil {
    /***
     * 将请求对象传入，进行对象转Map，排序，进行MD5加密；
     *
     * @param req
     * @return
     */
    private static StringBuilder stringBuilder;

    private static String currTime;

    /***
     * hashCode加密字符串
     *
     * @return
     */
    public static LinkedHashMap<String, Object> ParameToMap(Object reqData) {
        stringBuilder = new StringBuilder();
        stringBuilder.append("he3yun.com-");
        @SuppressWarnings("unchecked")
        LinkedHashMap<String, Object> map = ZJ_BeanToMapUtils.toMap(reqData);
        List<Map.Entry<String, Object>> list = new ArrayList<Map.Entry<String, Object>>(map.entrySet());
        Collections.sort(list, new Comparator<Map.Entry<String, Object>>() {
            public int compare(Entry<String, Object> o1, Entry<String, Object> o2) {
                return String.valueOf(o1.getValue()).toLowerCase()
                        .compareTo(String.valueOf(o2.getValue()).toLowerCase());
            }
        });
        return CheckData(reqData, list);
    }

    /***
     * 根据不同的构造方法参数生成对应Map对象，进行加密
     *
     * @param reqData
     * @param list
     * @return
     */
    private static LinkedHashMap<String, Object> CheckData(Object reqData, List<Map.Entry<String, Object>> list) {
        LinkedHashMap<String, Object> dataMap = new LinkedHashMap<String, Object>();

        return traverseEntryToMap(reqData, dataMap, list);
    }

    /***
     * 提高复用写的方法
     *
     * @param dataMap
     * @param list
     * @return
     */

    private static LinkedHashMap<String, Object> traverseEntryToMap(Object reqData,
                                                                    LinkedHashMap<String, Object> dataMap, List<Map.Entry<String, Object>> list) {
        for (Entry<String, Object> mapping : list) {
            if (mapping.getValue() != null) {
                stringBuilder.append(String.valueOf(mapping.getValue()) + "-");
                dataMap.put(mapping.getKey(), mapping.getValue());
            }
        }
        getCurrTime();
        stringBuilder.append(currTime);

        dataMap.put("hashCode", MD5Util.stringToMD5(String.valueOf(stringBuilder)));
        dataMap.put("timestamp", currTime);

        return dataMap;
    }

    public static void getCurrTime() {
        currTime = String.valueOf(new Date().getTime());
    }

    /**
     * MAP排序
     * @param map
     */
    public static LinkedHashMap<String, Object> sortMap(LinkedHashMap<String, Object> map) {
        List<Map.Entry<String, Object>> list = new ArrayList<Map.Entry<String, Object>>(map.entrySet());
        Collections.sort(list, new Comparator<Map.Entry<String, Object>>() {
            public int compare(Entry<String, Object> o1, Entry<String, Object> o2) {
                return String.valueOf(o1.getValue()).toLowerCase()
                        .compareTo(String.valueOf(o2.getValue()).toLowerCase());
            }
        });
        return map;
    }

}

反射对象生成没有null的map:

public static <K, V> LinkedHashMap<K, V> toMap(Object javaBean) {
        LinkedHashMap<K, V> ret = new LinkedHashMap<K, V>();
        try {
            Method[] methods = javaBean.getClass().getDeclaredMethods();
            for (Method method : methods) {
                if (method.getName().startsWith("get")) {
                    String field = method.getName();
                    field = field.substring(field.indexOf("get") + 3);
                    field = field.toLowerCase().charAt(0) + field.substring(1);
                    Object value = method.invoke(javaBean, (Object[]) null);
                    ret.put((K) field, (V) (null == value ? null : value));
                }
            }
        } catch (Exception e) {
        }
        return ret;
    }