java - 如何使用 Jackson 解析具有不同类型的无名数组

Question

我有一些 json 数据，看起来像

"value": [ 1572553480.732, "118" ]

解析器因“无法构造 Value 实例(不存在像默认构造那样的创建者):没有双/双参数构造函数/工厂方法来从 Number 值 (1.572553780732E9) 反序列化”而窒息”

我的数据类如下所示:

public class Value {
  private double uTime;
  private String count;
  public Value() { super(); }
  public Value(double uTime, String count) {...}
  // also getters and setters for both
}

Answer 1

您可以将@JsonFormat注释与JsonFormat.Shape.ARRAY形状一起使用:

import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonPathApp {

    public static void main(String[] args) throws Exception {
        ObjectMapper mapper = new ObjectMapper();

        String json = "{\"value\": [ 1572553480.732, \"118\" ]}";
        System.out.println(mapper.readValue(json, Root.class));
    }
}

class Root {

    @JsonFormat(shape = JsonFormat.Shape.ARRAY)
    private Value value;

    // getters, setters, toString
}

上面的代码打印:

Root{value=Value{uTime=1.572553480732E9, count='118'}}