spring boot 使用 json 響應時去除 null 的字段

代碼如下：

import java.io.Serializable;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonInclude.Include;

public class RespObject implements Serializable {

    private static final long serialVersionUID = -1560603887556641494L;

    ....

    @JsonInclude(Include.NON_NULL)
    public Object respMsg;

    @JsonInclude(Include.NON_NULL)
    public Object respData;

    ....

}