将json数组值反序列化到特定的Java类字段
我有下面的Json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",
{
"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]