Java Map按照Key和Value排序【轉】

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package kingtool.sort;import java.util.ArrayList;import java.util.Collections;import java.util.Comparator;import java.util.Iterator;import java.util.LinkedHashMap;import java.util.List;import java.util.Map;import java.util.TreeMap;import java.util.Map.Entry;/** *  * @author King * */public class MapSortTool {    public static void main(String[] args) {        Map<String, String> map = new TreeMap<String, String>();        map.put("4", "2");        map.put("1", "1");        map.put("9", "3");        map.put("8", "6");//      Map<String, String> resultMap = sortMapByKey(map); //按Key進行排序        Map<String, String> resultMap = sortMapByValue(map); // 按Value進行排序        for (Map.Entry<String, String> entry : resultMap.entrySet()) {            System.out.println(entry.getKey() + " " + entry.getValue());        }    }    /**     * 使用 Map按key進行排序     *      * @param map     * @return     */    public static Map<String, String> sortMapByKey(Map<String, String> map) {        if (map == null || map.isEmpty()) {            return null;        }        Map<String, String> sortMap = new TreeMap<String, String>(new MapKeyStringComparator());        sortMap.putAll(map);        return sortMap;    }    /**     * 使用 Map按value進行排序     *      * @param map     * @return     */    public static Map<String, String> sortMapByValue(Map<String, String> oriMap) {        if (oriMap == null || oriMap.isEmpty()) {            return null;        }        Map<String, String> sortedMap = new LinkedHashMap<String, String>();        List<Map.Entry<String, String>> entryList = new ArrayList<Map.Entry<String, String>>(oriMap.entrySet());        Collections.sort(entryList, new MapValueStringComparator());        Iterator<Map.Entry<String, String>> iter = entryList.iterator();        Map.Entry<String, String> tmpEntry = null;        while (iter.hasNext()) {            tmpEntry = iter.next();            sortedMap.put(tmpEntry.getKey(), tmpEntry.getValue());        }        return sortedMap;    }    /**     * string key升序     * @author King     *     */    static class MapKeyStringComparator implements Comparator<String>{        @Override        public int compare(String str1, String str2) {            return str1.compareTo(str2);        }    }        /**     * string value升序     * @author King     *     */    static class MapValueStringComparator implements Comparator<Map.Entry<String, String>> {        @Override        public int compare(Entry<String, String> entry1, Entry<String, String> entry2) {            return entry1.getValue().compareTo(entry2.getValue());        }    }            /**     * tip: 範例中沒用到<br/>     * double value降序     * @author King     *     */    static class MapValueNumberComparator implements Comparator<Map.Entry<String, Double>> {        @Override        public int compare(Entry<String, Double> entry1, Entry<String, Double> entry2) {            return entry1.getValue().compareTo(entry2.getValue());        }    }}

 

Java Map按照Key和Value排序【轉】