将json数组值反序列化到特定的Java类字段

将json数组值反序列化到特定的Java类字段,java,json,jackson,deserialization,json-deserialization,Java,Json,Jackson,Deserialization,Json Deserialization,我有下面的Json { "coreId" : "1", "name" : "name", "additionalValueList" : [ { "columnName" : "allow_duplicate", "rowId" : "10", "value" : "1" }, { "columnName" : "include_in_display",

我有下面的Json

    {
    "coreId" : "1",
    "name" : "name",
    "additionalValueList" : [
      {
       "columnName" : "allow_duplicate",
       "rowId"  : "10",
       "value" :  "1"
      },
      {
       "columnName" : "include_in_display",
       "rowId"  : "11",
       "value" :  "0"
      },
      ...e.t.c
     ]
 },
 ...e.t.c
和Java类

class DTO {
@JsonProperty("coreId")
private Integer id;

private String name;

private Boolean allowDuplicate;

private Boolean includeInDisplay;
}
如何轻松地将“additionalValueList”中的值映射到相应的java字段。例如,字段“columnName”-“allow_duplicate”=DTO.allowDuplicate中的Json值。 事实上,我知道如何使用带有@JsonDeserialize注释和smth的自定义反序列化程序来实现这一点。但是我有40多个DTO,为每个字段创建自己的反序列化程序不是一个好主意。我正在寻找一种解决方案,例如使用1反序列化器(因为'additionalValueList'中的值结构对于所有实体都是相同的),并将参数(我要映射到该字段的字段名)传递给自定义反序列化器,该反序列化器将在'additionalValueList'实体中找到'column name'=参数(我从注释传递的参数)并返回“value”。 范例

这将是一个很好的解决方案,但可能不容易实现。但是我将非常感谢您的所有建议。谢谢。

创建一个类,然后在DTO类中指定它

为了简化示例,以下代码使用了
public
字段

/**
 * Intermediate object used for deserializing FooDto from JSON.
 */
public final class FooJson {

    /**
     * Converter used when deserializing FooDto from JSON.
     */
    public static final class ToDtoConverter extends StdConverter<FooJson, FooDto> {
        @Override
        public FooDto convert(FooJson json) {
            FooDto dto = new FooDto();
            dto.name = json.name;
            dto.id = json.coreId;
            dto.allowDuplicate = lookupBoolean(json, "allow_duplicate");
            dto.includeInDisplay = lookupBoolean(json, "include_in_display");
            return dto;
        }
        private static Boolean lookupBoolean(FooJson json, String columnName) {
            String value = lookup(json, columnName);
            return (value == null ? null : (Boolean) ! value.equals("0"));
        }
        private static String lookup(FooJson json, String columnName) {
            if (json.additionalValueList != null)
                for (FooJson.Additional additional : json.additionalValueList)
                    if (columnName.equals(additional.columnName))
                        return additional.value;
            return null;
        }
    }

    public static final class Additional {
        public String columnName;
        public String rowId;
        public String value;
    }

    public Integer coreId;
    public String name;
    public List<Additional> additionalValueList;
}
试验

输出


谢谢你的回答!这听起来是个好主意,但问题是,使用这种方法,我必须为每个DTO类创建ToToConverter。实际上这不是问题,但我有40个具有不同字段名的类。所以,如果我找不到更多的解决方案,我会试试你的。谢谢。你不能在酒店层面这样做。您需要为
DTO
类编写一个通用的自定义反序列化程序,并将此逻辑放在那里。要实现通用解决方案,我们需要更多信息。另一个
DTO
类是什么样子的?它们是否具有与
additionalValueList
数组中的对象相关的常规属性和布尔属性的相同结构?您是否将所有这些
DTO
类放在一个包中?您使用哪个版本的
Java
/**
 * Intermediate object used for deserializing FooDto from JSON.
 */
public final class FooJson {

    /**
     * Converter used when deserializing FooDto from JSON.
     */
    public static final class ToDtoConverter extends StdConverter<FooJson, FooDto> {
        @Override
        public FooDto convert(FooJson json) {
            FooDto dto = new FooDto();
            dto.name = json.name;
            dto.id = json.coreId;
            dto.allowDuplicate = lookupBoolean(json, "allow_duplicate");
            dto.includeInDisplay = lookupBoolean(json, "include_in_display");
            return dto;
        }
        private static Boolean lookupBoolean(FooJson json, String columnName) {
            String value = lookup(json, columnName);
            return (value == null ? null : (Boolean) ! value.equals("0"));
        }
        private static String lookup(FooJson json, String columnName) {
            if (json.additionalValueList != null)
                for (FooJson.Additional additional : json.additionalValueList)
                    if (columnName.equals(additional.columnName))
                        return additional.value;
            return null;
        }
    }

    public static final class Additional {
        public String columnName;
        public String rowId;
        public String value;
    }

    public Integer coreId;
    public String name;
    public List<Additional> additionalValueList;
}
@JsonDeserialize(converter = FooJson.ToDtoConverter.class)
public final class FooDto {
    public Integer id;
    public String name;
    public Boolean allowDuplicate;
    public Boolean includeInDisplay;

    @Override
    public String toString() {
        return "FooDto[id=" + this.id +
                    ", name=" + this.name +
                    ", allowDuplicate=" + this.allowDuplicate +
                    ", includeInDisplay=" + this.includeInDisplay + "]";
    }
}
ObjectMapper mapper = new ObjectMapper();
FooDto foo = mapper.readValue(new File("test.json"), FooDto.class);
System.out.println(foo);
FooDto[id=1, name=name, allowDuplicate=true, includeInDisplay=false]