Java Map 求交集 并集 差集

import com.google.common.collect.MapDifference;
import com.google.common.collect.Maps;

import java.util.Map;

public class MapUtil {

    /**
     * difference
     * Maps.difference(Map, Map)用来比较两个Map以获取所有不同点。该方法返回MapDifference对象
     */
    public static void u(Map<String,Object> map1, Map<String,Object> map2) {
        MapDifference<String, Object> difference = Maps.difference(map1, map2);
        // 是否有差异，返回boolean
        boolean areEqual = difference.areEqual();
        System.out.println("比较两个Map是否有差异:" + areEqual);
        // 两个map的交集
        Map<String, Object> entriesInCommon = difference.entriesInCommon();
        System.out.println("两个map都有的部分（交集）===：" + entriesInCommon);
        // 键相同但是值不同值映射项。返回的Map的值类型为MapDifference.ValueDifference，以表示左右两个不同的值
        Map<String, MapDifference.ValueDifference<Object>> entriesDiffering = difference.entriesDiffering();
        System.out.println("键相同但是值不同值映射项===：" + entriesDiffering);
        // 键只存在于左边Map的映射项
        Map<String, Object> onlyOnLeft = difference.entriesOnlyOnLeft();
        System.out.println("键只存在于左边Map的映射项:" + onlyOnLeft);
        // 键只存在于右边Map的映射项
        Map<String, Object> entriesOnlyOnRight = difference.entriesOnlyOnRight();
        System.out.println("键只存在于右边Map的映射项:" + entriesOnlyOnRight);
    }
}