Java Stream处理

    public static void main(String[] args){
        List<Map<String, String>> listMaps = new ArrayList<>();
        Map<String, String> map1 = new HashMap<>();
        map1.put("name", "haha");
        map1.put("user", "shaha");
        map1.put("pass", "shaha***");
        Map<String, String> map2 = new HashMap<>();
        map2.put("name", "haha-2");
        map2.put("user", "shaha2");
        map2.put("pass", "shaha***2");
        Map<String, String> map3 = new HashMap<>();
        map3.put("names", "haha-3");
        map3.put("user", "shaha3");
        map3.put("pass", "shaha***3");

        listMaps.add(map1);
        listMaps.add(map2);
        listMaps.add(map3);

        for (Map<String, String> map : listMaps) {
            System.out.println(map.toString());
        }
        System.out.println(listMaps.get(0).keySet());
        // 行过滤
        listMaps.stream().map(map -> map.get("name")).collect(Collectors.toList());
        // System.out.println(listMaps.stream().filter(map -> map.containsKey("name")).collect(Collectors.toList()));
        System.out.println(listMaps.stream().map(map -> map.get("name")+","+map.get("user")).collect(Collectors.toList()));
    }