Jackson将类中的所有空字符串反序列化为null

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;

import java.io.IOException;

public class EmptyStringToNullDeserializer extends JsonDeserializer<Object> {

    @Override
    public Object deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
        String value = p.getValueAsString();
        return "".equals(value) ? null : value;
    }
}

import com.fasterxml.jackson.databind.annotation.JsonDeserialize;

public class YourEntity {

    private Long id;

    @JsonDeserialize(using = EmptyStringToNullDeserializer.class)
    private String name;

    // Getters and setters
}

import com.fasterxml.jackson.databind.ObjectMapper;

public class Main {

    public static void main(String[] args) {
        String jsonString = "{\"id\":1,\"name\":\"\"}";

        ObjectMapper mapper = new ObjectMapper();
        try {
            YourEntity entity = mapper.readValue(jsonString, YourEntity.class);
            System.out.println(entity.getId());
            System.out.println(entity.getName());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

1
null