使用java 8更新列表中映射中的值

List<Map<String, Integer>> list = new ArrayList<>();

Map<String, Integer> map1 = new HashMap<>();
map1.put("key1", 1);
map1.put("key2", 2);
list.add(map1);

Map<String, Integer> map2 = new HashMap<>();
map2.put("key3", 3);
map2.put("key4", 4);
list.add(map2);

list.forEach(map -> map.compute("key1", (key, value) -> value != null ? value + 10 : null));

list.forEach(System.out::println);

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Main {
    public static void main(String[] args) {
        List<Map<String, Integer>> list = new ArrayList<>();

        Map<String, Integer> map1 = new HashMap<>();
        map1.put("key1", 1);
        map1.put("key2", 2);
        list.add(map1);

        Map<String, Integer> map2 = new HashMap<>();
        map2.put("key3", 3);
        map2.put("key4", 4);
        list.add(map2);

        list.forEach(map -> map.compute("key1", (key, value) -> value != null ? value + 10 : null));

        list.forEach(System.out::println);
    }
}

{key1=11, key2=2}
{key3=3, key4=4}