根据Map的value值进行排序-map排序

Bertha 。 2022-09-10 12:24 305阅读 0赞

package com.sm.util;
    
    import java.util.ArrayList;
    import java.util.Collections;
    import java.util.Comparator;
    import java.util.LinkedHashMap;
    import java.util.List;
    import java.util.Map;
    
    /** * 根据map的value值进行升序或者降序排列。 * @author Administrator * */
    public class MapValueSortUtils { 
    
    	// Map的value值降序排序
        public static <K, V extends Comparable<? super V>> Map<K, V> sortDescend(Map<K, V> map) { 
            List<Map.Entry<K, V>> list = new ArrayList<>(map.entrySet());
            Collections.sort(list, new Comparator<Map.Entry<K, V>>() { 
                @Override
                public int compare(Map.Entry<K, V> o1, Map.Entry<K, V> o2) { 
                    int compare = (o1.getValue()).compareTo(o2.getValue());
                    return -compare;
                }
            });
     
            Map<K, V> returnMap = new LinkedHashMap<K, V>();
            for (Map.Entry<K, V> entry : list) { 
                returnMap.put(entry.getKey(), entry.getValue());
            }
            return returnMap;
        }
     
        // Map的value值升序排序
        public static <K, V extends Comparable<? super V>> Map<K, V> sortAscend(Map<K, V> map) { 
            List<Map.Entry<K, V>> list = new ArrayList<Map.Entry<K, V>>(map.entrySet());
            Collections.sort(list, new Comparator<Map.Entry<K, V>>() { 
                @Override
                public int compare(Map.Entry<K, V> o1, Map.Entry<K, V> o2) { 
                    int compare = (o1.getValue()).compareTo(o2.getValue());
                    return compare;
                }
            });
     
            Map<K, V> returnMap = new LinkedHashMap<K, V>();
            for (Map.Entry<K, V> entry : list) { 
                returnMap.put(entry.getKey(), entry.getValue());
            }
            return returnMap;
        }
    }