在jsonnode上应用一些条件并在Java中过滤结果集

Question

我有一个Jsonnodes数组。差不多吧

[
 {
   "coupon": "VAR",
   "currency": "USD",
   "sip": "94989WAX5",
   "lastModifiedDate": "2022-09-23T08:16:25Z"
  },
  {
   "coupon": "VAR1",
   "currency": "USD",
   "sip": "94989WAX5",
   "lastModifiedDate": "2022-09-21T08:16:25Z"
  },
  {
   "coupon": "VAR3",
   "currency": "USD",
   "sip": "XHBRYWEB1",
   "lastModifiedDate": "2022-09-20T08:16:25Z"
  }
 ]

我有一个要求，如果两个节点的sip值相同，那么我只需要选择最后修改日期是最新的sip。在上面的例子中，最终输出应该是剩余的两个节点。

 [
  {
   "coupon": "VAR",
   "currency": "USD",
   "sip": "94989WAX5",
   "lastModifiedDate": "2022-09-23T08:16:25Z"
  },
  {
   "coupon": "VAR3",
   "currency": "USD",
   "sip": "XHBRYWEB1",
   "lastModifiedDate": "2022-09-20T08:16:25Z"
  }
 ]

我试图通过创建< code>HashMap来解决这个问题

Answer 1

https://github.com/octomix/josson

反序列化

Josson josson = Josson.fromJsonString(
    "[" +
    " {" +
    "   \"coupon\": \"VAR\"," +
    "   \"currency\": \"USD\"," +
    "   \"sip\": \"94989WAX5\"," +
    "   \"lastModifiedDate\": \"2022-09-23T08:16:25Z\"" +
    "  }," +
    "  {" +
    "   \"coupon\": \"VAR1\"," +
    "   \"currency\": \"USD\"," +
    "   \"sip\": \"94989WAX5\"," +
    "   \"lastModifiedDate\": \"2022-09-21T08:16:25Z\"" +
    "  }," +
    "  {" +
    "   \"coupon\": \"VAR3\"," +
    "   \"currency\": \"USD\"," +
    "   \"sip\": \"XHBRYWEB1\"," +
    "   \"lastModifiedDate\": \"2022-09-20T08:16:25Z\"" +
    "  }" +
    " ]");

转型

JsonNode node = josson.getNode("group(sip)@.elements.findByMax(lastModifiedDate)");
System.out.println(node.toPrettyString());

输出

[ {
  "coupon" : "VAR",
  "currency" : "USD",
  "sip" : "94989WAX5",
  "lastModifiedDate" : "2022-09-23T08:16:25Z"
}, {
  "coupon" : "VAR3",
  "currency" : "USD",
  "sip" : "XHBRYWEB1",
  "lastModifiedDate" : "2022-09-20T08:16:25Z"
} ]

Answer 2

Map<String, JsonNode> map =
    jsonNodeList.stream()
        .collect(
            toMap(
                jsonNode -> jsonNode.get("sip").asText(),
                jsonNode -> jsonNode,
                (jsonNode1, jsonNode2) -> {
                  boolean after =
                      LocalDateTime.parse(String.valueOf(jsonNode1.get("lastModifiedDate")))
                          .isAfter(
                              LocalDateTime.parse(
                                  String.valueOf(jsonNode2.get("lastModifiedDate"))));
                  return after ? jsonNode1 : jsonNode2;
                },
                HashMap::new));