Jackson-annotations-jsondeserialize

ジャクソン注釈-@JsonDeserialize

*@ JsonDeserialize* は、カスタムデシリアライザーを指定してjsonオブジェクトを非整列化するために使用されます。

例@JsonDeserialize

import java.io.IOException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;

public class JacksonTester {
   public static void main(String args[]) throws ParseException{
      ObjectMapper mapper = new ObjectMapper();
      String jsonString = "{\"name\":\"Mark\",\"dateOfBirth\":\"20-12-1984\"}";
      try {
         Student student = mapper
            .readerFor(Student.class)
            .readValue(jsonString);
         System.out.println(student.dateOfBirth);
      }
      catch (IOException e) {
         e.printStackTrace();
      }
   }
}
class Student {
   public String name;
   @JsonDeserialize(using = CustomDateDeserializer.class)
   public Date dateOfBirth;
}
class CustomDateDeserializer extends StdDeserializer<Date> {
   private static final long serialVersionUID = 1L;
   private static SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy");
   public CustomDateDeserializer() {
      this(null);
   }
   public CustomDateDeserializer(Class<Date> t) {
      super(t);
   }
   @Override
   public Date deserialize(JsonParser parser, DeserializationContext context)
      throws IOException, JsonProcessingException {

      String date = parser.getText();
      try {
         return formatter.parse(date);
      }
      catch (ParseException e) {
         e.printStackTrace();
      }
      return null;
   }
}

出力

Thu Dec 20 00:00:00 IST 1984