stream()流使用

String aaa = “aaa”;
List<Map<String, Object>> riskDataList = new ArrayList<>();
Map<String, Object> map = new HashMap<>();
Map<String, Object> map1 = new HashMap<>();
Map<String, Object> map2 = new HashMap<>();
map.put(“1”, 1);
map1.put(“1”, “”);
map2.put(“1”, 3);
riskDataList.add(map);
riskDataList.add(map1);
riskDataList.add(map2);
aaa += riskDataList.stream().filter(t -> t.get(“1”) != null).map(t ->
“mapValue” + t.get(“1”)
).collect(Collectors.joining("; ", “*”, “#”));

    List<String> collect = riskDataList.stream().filter(t -> t.get("1") != null && t.get("1") != "").map(t -> String.valueOf(t.get("1"))).distinct().collect(Collectors.toList());
    String collect1 = collect.stream().map(t -> "value" + t).collect(Collectors.joining(",", "", ""));
    System.out.println(collect);
    riskDataList.clear();
    List<String> collect2 = riskDataList.stream().filter(t -> t.get("1") != null && t.get("1") != "").map(t -> String.valueOf(t.get("1"))).distinct().collect(Collectors.toList());
    System.out.println(collect2);