使用Jackson将Json数组映射到POJO

Question

[
 [
  1232324343,
  "A",
  "B",
  3333,
  "E"
 ],
 [
  12345424343,
  "N",
  "M",
  3133,
  "R"
 ]
]

ABC abc = new ABC();
ObjectMapper mapper = new ObjectMapper();
JsonNode jsonNode = mapper.readTree(data).get("results");

if (jsonNode.isArray()) {
    for (JsonNode node : jsonNode) {
        String nodeContent = mapper.writeValueAsString(node);
        abc = mapper.readValue(nodeContent,ABC.class);

        System.out.println("Data: " + abc.getA());
    }
}

JSONMappingException：无法反序列化com.demo.json.model.abc实例

编辑：我的POJO如下所示：

class ABC{
    long time;
    String a;
    String b;
    int status;
    String c;
}

有人能提出解决办法吗？

ABC[] abc = mapper.readValue(nodeContent, ABC[].class);

mapper.configure(DeserializationFeature.USE_LONG_FOR_INTS, true);

有人能帮我做这个吗？

Answer 1

可以对此对象使用数组形状。您可以使用JSONFormat注释来完成：

@JsonFormat(shape = Shape.ARRAY)
class ABC {

并将其反序列化：

ABC[] abcs = mapper.readValue(json, ABC[].class);

示例代码可以如下所示：

JsonNode jsonNode = mapper.readTree(json);
if (jsonNode.isArray()) {
    for (JsonNode node : jsonNode) {
        String nodeContent = mapper.writeValueAsString(node);
        ABC abc = mapper.readValue(nodeContent, ABC.class);

        System.out.println("Data: " + abc.getA());
    }
}

JsonNode jsonNode = mapper.readTree(json);
if (jsonNode.isArray()) {
    for (JsonNode node : jsonNode) {
        ABC abc = mapper.convertValue(node, ABC.class);
        System.out.println("Data: " + abc.getA());
    }
}

JsonNode jsonNode = mapper.readTree(json);
ABC[] abc = mapper.convertValue(jsonNode, ABC[].class);
System.out.println(Arrays.toString(abc));