spring/jackson:实现对保存JSON字符串的字段自动序列化和反序列化

public static class JsonTestUser{
		private Integer id;
		private String name;
		/** (JSON格式)扩展字段 */
		private String props;
		......//
}

{
  "id":0,
  "name":"tom",
  "props":{
    "phone":"13088927898",
    "email":"hello@qq.com"
  }
}

@JsonRawValue
private String props;

import java.io.IOException;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
/**
 * Deserializing JSON property as String with Jackson<br>
 * 实现将有{@link com.fasterxml.jackson.annotation.JsonRawValue}注解的
 * 内容为JSON的String类型字段反序列化为String的反序列化器实现
 * copy from <a ref="https://cassiomolin.com/2017/01/24/deserializing-json-property-as-string-with-jackson/">《Deserializing JSON property as String with Jackson》</a>
 *
 */
public class RawJsonDeserializer extends JsonDeserializer<String> {

    @Override
    public String deserialize(JsonParser jp, DeserializationContext ctxt)
           throws IOException, JsonProcessingException {
    	/**
    	 * 如果希望保存原始字符串内容,空格,tab,换行，则采用如下方式,不解析为JSON对象直接将原字符串返回
    	 */
        long begin = jp.getCurrentLocation().getCharOffset();
        jp.skipChildren();
        long end = jp.getCurrentLocation().getCharOffset();

        String json = jp.getCurrentLocation().getSourceRef().toString();
        return json.substring((int) begin - 1, (int) end);
    }
}

@JsonRawValue
@JsonDeserialize(using = RawJsonDeserializer.class)
private String props;