文件大小转换成可显示的Mb,Gb和kb方法

public static String unitConversion(float resource) {
        String[] unit = new String[] { "B", "KB", "M", "G", "T" };
        String formResult = "";
        for (int j = 0; j < unit.length; j++) {
            if (resource < 1024) {
                formResult = resource + unit[j];
                break;
            }
            resource = resource / 1024f;
        }
        return formResult;
    }

    public static String convertFileSize(long size) {
        long kb = 1024;
        long mb = kb * 1024;
        long gb = mb * 1024;

        if (size >= gb) {
            return String.format("%.1f GB", (float) size / gb);
        } else if (size >= mb) {
            float f = (float) size / mb;
            return String.format(f > 100 ? "%.0f MB" : "%.1f MB", f);
        } else if (size >= kb) {
            float f = (float) size / kb;
            return String.format(f > 100 ? "%.0f KB" : "%.1f KB", f);
        } else
            return String.format("%d B", size);
    }