[英]Deserializing attributes of same name but different types in Jackson?
I have a REST API which returns a JSON response as: 我有一个REST API,它返回一个JSON响应:
{
"channel" : "JHBHS"
}
and sometimes it returns: 有时会返回:
{
"channel": {
"id": 12321,
"name": "Some channel"
}
}
I have a POJO like: 我有一个像POJO:
public class Event {
private String channel;
@JsonProperty("channel")
private Channel channelObj;
}
public class Channel {
private int id;
private String name;
}
So, is there a way (other than writing your own custom deserializer ) in Jackson2 which will help me map channel
in JSON to String
type when it's a String
and Channel
type when it's a JSON Object? 那么,在Jackson2中是否有一种方法(除了编写自己的自定义反序列化器 ),这将帮助我将JSON中的
channel
映射到String
类型,当它是一个JSON对象时是String
和Channel
类型?
Or in other words, is there a way in Jackson which maps by type
of the variable and not just by name
? 或者换句话说,杰克逊有没有一种方法可以按变量的
type
而不是按name
进行映射?
I can suggest you to use JsonNode like this: 我建议你像这样使用JsonNode :
class Event {
@JsonProperty("channel")
private JsonNode channelInternal;
private Channel channel;
private String channelStr;
/**
* Custom getter with channel parsing
* @return channel
*/
public Channel getChannel() {
if (channel == null && channelInternal != null) {
if (channelInternal.isObject()) {
int id = channelInternal.get("id").intValue();
String name = channelInternal.get("name").asText();
channel = new Channel(id, name);
}
}
return channel;
}
/**
* Custom getter with channel string parsing
* @return channel string
*/
public String getChannelStr() {
if (channelStr == null && channelInternal != null) {
if (channelInternal.isTextual()) {
channelStr = channelInternal.asText();
}
}
return channelStr;
}
}
or like this : 或者像这样 :
class Event {
private Channel channel;
private String channelStr;
@JsonSetter("channel")
public void setChannelInternal(JsonNode channelInternal) {
if (channelInternal != null) {
if (channelInternal.isTextual()) {
channelStr = channelInternal.asText();
} else if (channelInternal.isObject()) {
int id = channelInternal.get("id").intValue();
String name = channelInternal.get("name").asText();
channel = new Channel(id, name);
}
}
}
public Channel getChannel() {
return channel;
}
public String getChannelStr() {
return channelStr;
}
}
But I think using custom deserializer is more common. 但我认为使用自定义解串器更常见。
Here is test code 这是测试代码
public static void main(String[] args) throws IOException {
ObjectMapper objectMapper = new ObjectMapper();
String source1 = "{\n" +
" \"channel\" : \"JHBHS\"\n" +
"}";
String source2 = "{\n" +
" \"channel\": {\n" +
" \"id\": 12321,\n" +
" \"name\": \"Some channel\"\n" +
" }\n" +
"}";
//Test object parsing
Event result = objectMapper.readValue(source2, Event.class);
System.out.println(String.format("%s : %s", result.getChannel().getId(), result.getChannel().getName()));
//Test string parsing
result = objectMapper.readValue(source1, Event.class);
System.out.println(result.getChannelStr());
}
And the output: 并输出:
12321 : Some channel
JHBHS
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.