Java 使用jackson反序列化包含@JsonFormat（shape=JsonFormat.shape.ARRAY）和自定义对象的json

我有一个自定义对象：

public class Response
{
    @JsonProperty("values")
    private List<Value> values;

    @JsonFormat(shape=JsonFormat.Shape.ARRAY)
    public static class Value {

        public Value(long timestamp, float val)
        {
            this.timestamp = timestamp;
            this.val = val;
        }
    }
}

---

知道我是不是遗漏了什么吗？或者我应该有一个自定义的反序列化程序来执行此操作吗？

您应该

JsonFormat

覆盖变量

值。另外，由于变量的类型为
List
，因此不需要添加
JsonFormat

public class Response
    {
        @JsonProperty("values")
        @JsonFormat(shape=JsonFormat.Shape.ARRAY)
        private List<Value> values;

        public static class Value {
            private long timestamp;
            private float val;

            // Getters and Setters

            public Value(long timestamp, float val)
            {
                this.timestamp = timestamp;
                this.val = val;
            }
        }
    }

希望这有帮助！！我还没有测试代码，所以如果有语法问题，请忽略。
JsonFormat
会起作用，但您还需要使用
JsonCreator
注释声明构造函数。请看下面的示例：

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

import java.io.File;
import java.util.List;

public class JsonApp {

    public static void main(String[] args) throws Exception {
        File jsonFile = new File("./resource/test.json").getAbsoluteFile();

        ObjectMapper mapper = new ObjectMapper();
        Response myPojo = mapper.readValue(jsonFile, Response.class);
        System.out.println(myPojo);
    }
}

class Response {

    private List<Value> values;

    public List<Value> getValues() {
        return values;
    }

    public void setValues(List<Value> values) {
        this.values = values;
    }

    @Override
    public String toString() {
        return "Response{" +
                "values=" + values +
                '}';
    }
}

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

    private long timestamp;
    private float val;

    @JsonCreator
    public Value(@JsonProperty("timestamp") long timestamp, @JsonProperty("val") float val) {
        this.timestamp = timestamp;
        this.val = val;
    }

    public long getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(long timestamp) {
        this.timestamp = timestamp;
    }

    public float getVal() {
        return val;
    }

    public void setVal(float val) {
        this.val = val;
    }

    @Override
    public String toString() {
        return "Value{" +
                "timestamp=" + timestamp +
                ", val=" + val +
                '}';
    }
}

印刷品：

Response{values=[Value{timestamp=1552215648, val=18.0}, Value{timestamp=123, val=12.24}]}

啊，变量值上的JsonFormat也没有帮助。：/变量是列表的列表，对吗？所以对于内部列表，我需要JsonFormat。不，输入格式会有所不同。我会在回答中加上这一点是的，不幸的是我没有'；我无法控制反应。它是一个长的和浮动的数组。不是地图。阵列将类似于[[157382008,45.5]]，谢谢Michal。这似乎奏效了。另外，我使用的是jackson.map的objectmapper，而不是jackson.databind。这也是一个不必要的错误。
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.File;
import java.util.List;

public class JsonApp {

    public static void main(String[] args) throws Exception {
        File jsonFile = new File("./resource/test.json").getAbsoluteFile();

        ObjectMapper mapper = new ObjectMapper();
        Response myPojo = mapper.readValue(jsonFile, Response.class);
        System.out.println(myPojo);
    }
}

class Response {

    private List<Value> values;

    public List<Value> getValues() {
        return values;
    }

    public void setValues(List<Value> values) {
        this.values = values;
    }

    @Override
    public String toString() {
        return "Response{" +
                "values=" + values +
                '}';
    }
}

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

    private long timestamp;
    private float val;

    @JsonCreator
    public Value(@JsonProperty("timestamp") long timestamp, @JsonProperty("val") float val) {
        this.timestamp = timestamp;
        this.val = val;
    }

    public long getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(long timestamp) {
        this.timestamp = timestamp;
    }

    public float getVal() {
        return val;
    }

    public void setVal(float val) {
        this.val = val;
    }

    @Override
    public String toString() {
        return "Value{" +
                "timestamp=" + timestamp +
                ", val=" + val +
                '}';
    }
}

{
  "values": [
    [
      1552215648,
      18
    ],
    [
      123,
      12.24
    ]
  ]
}

Response{values=[Value{timestamp=1552215648, val=18.0}, Value{timestamp=123, val=12.24}]}