hutool包将json串转为泛型类出现转换异常

hutool包将json串转为泛型类出现转换异常

问题描述：在使用hutool包的toBean方法转换json为泛型类之后，去获取泛型类的某个字段出现报错。java.lang.ClassCastException: cn.hutool.json.JSONObject cannot be cast toXXXX

造成原因：当使用JSONUtil将一串json转为一个泛型类，且指定转换的泛型为某一包含非String字段的对象时，会出现转换异常。

//泛型类
@Data
public class OperaterResult<T> {

    private String code;
 
    private String message;

    private Object data;
}

  HttpHeaders headers = new HttpHeaders();
  headers.setContentType(MediaType.APPLICATION_JSON);

  HttpEntity<OrderAi> requestEntity = new HttpEntity<>(orderAi,headers);
  //返回了一串json串"{"code":200,"message":"success","data":{"source":"文本分类","issueLv1":{"code":null,"name":"供用电合同管理","accuracyTag":"高"},"issueLv2":{"code":null,"name":"供用电法律关系缺失","accuracyTag":"高"},"issueLv3":{"code":null,"name":"合同超期未续签","accuracyTag":"低"}}}"
  ResponseEntity<String> aiVoResponseEntity = restTemplate.postForEntity(aiUrl, requestEntity, String.class);

  if(aiVoResponseEntity.getStatusCode() != HttpStatus.OK){
      throw new ServiceException("AI模型报错，请手动选择，并上报管理员！");
  }

  //将body中的json串转为OrderAiVo对象
  OperaterResult<OrderAiVo> orderAiVo= JSONUtil.toBean(aiVoResponseEntity.getBody(), OrderAiVo.class);

  //到这一步便会报错operaterResult.getData().getIssueLv1()
  //会报java.lang.ClassCastException: cn.hutool.json.JSONObject cannot be cast toXXXX
  String name = operaterResult.getData().getIssueLv1().getName();

解决方法：

  HttpHeaders headers = new HttpHeaders();
  headers.setContentType(MediaType.APPLICATION_JSON);

  HttpEntity<OrderAi> requestEntity = new HttpEntity<>(orderAi,headers);
  //返回了一串json串"{"code":200,"message":"success","data":{"source":"文本分类","issueLv1":{"code":null,"name":"供用电合同管理","accuracyTag":"高"},"issueLv2":{"code":null,"name":"供用电法律关系缺失","accuracyTag":"高"},"issueLv3":{"code":null,"name":"合同超期未续签","accuracyTag":"低"}}}"
  ResponseEntity<String> aiVoResponseEntity = restTemplate.postForEntity(aiUrl, requestEntity, String.class);

  if(aiVoResponseEntity.getStatusCode() != HttpStatus.OK){
      throw new ServiceException("AI模型报错，请手动选择，并上报管理员！");
  }

  //将body中的json串转为OperaterResult对象
  OperaterResult<JSONObject> jsonObject = JSONUtil.toBean(aiVoResponseEntity.getBody(), OperaterResult.class);

  //再对jsonObject里的data内容再做一次转换，转为OrderAiVo对象
  OrderAiVo orderAiVo = JSONUtil.toBean(jsonObject.getData(), OrderAiVo.class);
  
  //这样就不会报错了
  String name = orderAiVo.getIssueLv1().getName();