容量大小转换，KB/MB/GB/B

/**
 * 总大小
 */
@ApiModelProperty(value = "总大小")
private Long totalSize;


/**
 * 文件大小带单位
 */
@TableField(exist = false)
@ApiModelProperty(value = "文件大小带单位")
private String totalSizeName;


public void setTotalSize(Long totalSize) {
    this.totalSize = totalSize;
    if(1024*1024 > this.totalSize && this.totalSize >= 1024 ) {
        this.totalSizeName = String.format("%.2f",this.totalSize.doubleValue()/1024) + "KB";
    }else if(1024*1024*1024 > this.totalSize && this.totalSize >= 1024*1024 ) {
        this.totalSizeName = String.format("%.2f",this.totalSize.doubleValue()/(1024*1024)) + "MB";
    }else if(this.totalSize >= 1024*1024*1024 ) {
        this.totalSizeName = String.format("%.2f",this.totalSize.doubleValue()/(1024*1024*1024)) + "GB";
    }else {
        this.totalSizeName = this.totalSize.toString() + "B";
    }
}