[英]Inject a field in JSON Serialization
我想將一個字段注入從POJO序列化的JSON中。 我正在使用Jackson進行序列化,並且可以創建客戶序列化器以注入該字段。 到目前為止,我有:
public class Main {
public static void main(String[] args) throws IOException {
Child newChild = new Child();
newChild.setName("John");
ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule("Custom Child Serializer", new Version(1,0,0,null));
module.addSerializer(new CustomChildSerializer());
mapper.registerModule(module);
System.out.println(mapper.writeValueAsString(newChild));
System.in.read();
}
}
class CustomChildSerializer extends SerializerBase<Child> {
public CustomChildSerializer() {
super(Child.class);
}
@Override
public void serialize(Child child, JsonGenerator jgen, SerializerProvider serializerProvider) throws IOException, JsonGenerationException {
jgen.writeStartObject();
jgen.writeStringField("Name", child.getName());
jgen.writeStringField("Injected Value","Value");
jgen.writeEndObject();
}
}
class Child {
private String Name;
public String getName() { return Name; }
public void setName(String name) { Name = name; }
}
假設Child
是屬於API的類,而我無法對其進行修改。 有沒有一種方法可以修改自定義序列化程序,以對Child
類使用默認序列化,以便當Child
更改時,我不必修改自定義序列化程序?
您可以將對象轉換為Map
添加其他屬性並序列化完整Map。 請參見下面的序列化器:
class CustomChildSerializer extends JsonSerializer<Child> {
ObjectMapper mapper = new ObjectMapper();
MapType type = mapper.getTypeFactory().constructMapType(Map.class, String.class, String.class);
@Override
public void serialize(Child child, JsonGenerator jgen, SerializerProvider serializerProvider)
throws IOException, JsonGenerationException {
Map<String, String> map = mapper.convertValue(child, type);
map.put("Injected Value", "Value");
jgen.writeObject(map);
}
@Override
public Class<Child> handledType() {
return Child.class;
}
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.