使用Java中的可比接口按值对链接哈希表进行排序

int compare(T obj) ;


// Java program to sort the values of LinkedHashMap
// Importing required classes from
// java.util package
import java.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.*;
// Class 
public class GFG {
    // Main driver method
    public static void main(String[] args)
    {
        // Creating an LinkedHashMap object
        LinkedHashMap<String, Integer> l_map
            = new LinkedHashMap<String, Integer>();
        // Adding element to LinkedHashSet
        // Custom inputs
        l_map.put("Computer", 1);
        l_map.put("Science", 3);
        l_map.put("Portal", 2);
        // Display message
        System.out.print(
            "LinkedHashMap without sorting : ");
        // Print the elements of Map in above object
        // just after addition without sorting
        System.out.println(l_map);
        // Convert key-value from the LinkedHashMap to List
        // using entryset() method
        List<Map.Entry<String, Integer> > list
            = new ArrayList<Map.Entry<String, Integer> >(
                l_map.entrySet());
        // Comparable Interface function to
        // sort the values of List
        Collections.sort(
            list,
            new Comparator<Map.Entry<String, Integer> >() {
                // Comparing entries
                public int compare(
                    Entry<String, Integer> entry1,
                    Entry<String, Integer> entry2)
                {
                    return entry1.getValue()
                        - entry2.getValue();
                }
            });
        // Clear the above LinkedHashMap
        // using clear() method
        l_map.clear();
        // Iterating over elements using for each loop
        for (Map.Entry<String, Integer> entry : list) {
            // Put all sorted value back to the
            // LinkedHashMap
            l_map.put(entry.getKey(), entry.getValue());
        }
        // Display and print
        // the sorted value of LinkedHashMap
        System.out.println(
            "LinkedHashMap after sorting   : " + l_map);
    }
}


LinkedHashMap without sorting : {Computer=1, Science=3, Portal=2}
LinkedHashMap after sorting : {Computer=1, Portal=2, Science=3}