jsoninclude.include.non_null 不起作用问题

预览

在开发过程中，遇到在属性上加jsoninclude.include.non_null注解，有些属性起了作用，有些却没有起作用，下面使用代码简要说明一下：

@Data
public class demoBean {
    private String aNo;
    private String aName;
    private String aId;
    @JsonInclude(JsonInclude.Include.NON_NULL)
    private String aCount;
    @JsonInclude(JsonInclude.Include.NON_NULL)
    private String timeType;
    @JsonInclude(JsonInclude.Include.NON_NULL)
    private String timeLong;
}

发现timeType与timeLong为空时，过滤成功，aCount为空时，还是传递给了后端。

解决方案一：

@Data
@JsonInclude(JsonInclude.Include.NON_NULL)
public class demoBean {
    private String aNo;
    private String aName;
    private String aId;
    private String aCount;
    private String timeType;
    private String timeLong;
}

在类上加 @JsonInclude(JsonInclude.Include.NON_NULL)注解，发现没有问题。

解决方案二：

@Data
public class demoBean {
    private String aNo;
    private String aName;
    private String aId;
    // 该为非驼峰命名法，发现驼峰命名法，传给前端参数改为acount 小写
    @JsonInclude(JsonInclude.Include.NON_NULL)
    private String abCount;
    //private String aCount;
    @JsonInclude(JsonInclude.Include.NON_NULL)
    private String timeType;
    @JsonInclude(JsonInclude.Include.NON_NULL)
    private String timeLong;
}

把不起作用属性名改为非驼峰命名法，亦有效。

解决方案三（待测试）：

@Data
public class demoBean {
    private String aNo;
    private String aName;
    private String aId;
    @JsonProperty
    @JsonInclude(JsonInclude.Include.NON_NULL)
    private String aCount;
    @JsonInclude(JsonInclude.Include.NON_NULL)
    private String timeType;
    @JsonInclude(JsonInclude.Include.NON_NULL)
    private String timeLong;
}

属性前加 @JsonProperty 注解，该方案未测试，如读者有疑问，欢迎反馈。