jackson - ObjectMapper 정리 [계속..]
Posted on 2021. 7. 23. 10:44
Filed Under Programming/Java
배경: jackson 1.9 이하 버전에서 필요해짐.
출처: 직렬화&역직렬화
public class Coordinates {
byte red;
@JsonProperty("r")
public byte getR() {
return red;
}
@JsonProperty("red")
public void setRed(byte red) {
this.red = red;
}
}
///////
Coordinates obj = new Coordinates();
obj.setRed((byte) 5);
ObjectMapper mapper = new ObjectMapper();
System.out.println("Serialization: " + mapper.writeValueAsString(obj));
Coordinates r = mapper.readValue("{\"red\":25}",Coordinates.class);
System.out.println("Deserialization: " + r.getR());
///////결과:
Serialization: {"r":5}
Deserialization: 25
public static Map<String, Object> objectToMap(Object obj) {
ObjectMapper objectMapper = new ObjectMapper();
// objectMapper.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true);
// objectMapper.configure(Feature.AUTO_DETECT_FIELDS, true);
// value=null일때 처리
objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() {
@Override
public void serialize(Object value, JsonGenerator jgen, SerializerProvider provider) throws IOException {
jgen.writeString("");
}
});
// key=null일때 처리
objectMapper.getSerializerProvider().setNullKeySerializer(new JsonSerializer<Object>() {
@Override
public void serialize(Object value, JsonGenerator jgen, SerializerProvider serializers) throws IOException, JsonProcessingException {
jgen.writeFieldName("null");
}
});
@SuppressWarnings("unchecked")
Map<String, Object> map = objectMapper.convertValue(obj, Map.class);
return map;
}
반응형