java练习-集合遍历

package com.example.ss_0203_array.test.test_0815;

import java.util.*;

public class test1 {
    public static void main(String[] args) {
        HashMap<String, ArrayList> hMap = new HashMap<>();

        ArrayList city1 = new ArrayList<>();
        city1.add("AAA1");
        city1.add("AAA2");
        city1.add("AAA3");
        city1.add("AAA4");

        ArrayList city2 = new ArrayList<>();
        city2.add("BBB1");
        city2.add("BBB2");
        city2.add("BBB3");
        city2.add("BBB4");

        ArrayList city3 = new ArrayList<>();
        city3.add("CCC1");
        city3.add("CCC2");
        city3.add("CCC3");
        city3.add("CCC4");

        hMap.put("A",city1);
        hMap.put("B",city2);
        hMap.put("C",city3);

        Set<Map.Entry<String, ArrayList>> entries = hMap.entrySet();

        for (Map.Entry<String, ArrayList> entry : entries) {
            String key = entry.getKey();
            ArrayList<String> value = entry.getValue();
            StringJoiner sj = new StringJoiner(",","","");
            for (String city : value) {
                sj.add(city);
            }
            System.out.println(key + "==" + sj);
        }
    }
}