public String getTypeName(String url) { try { String type = FileTypeUtil.getType(new URL(url).openStream()); switch (type) { case "jpg": case "png": case "gif": case "tif": case "bmp": case "dwg": case "rft": case "psd": return "type_img"; case "rmvb": case "flv": case "mp4": case "mpg": case "wmv": case "wav": case "avi": return "type_video"; default: return "type_pdf"; } } catch (Exception e) { e.printStackTrace(); log.error("未找到对应的文件类型！"); } return null; }

这段代码看起来已经很简洁了，但是可以考虑以下几个优化点：

1. 可以将常量字符串提取成静态常量，避免多次创建字符串对象：

private static final String TYPE_IMG = "type_img";
private static final String TYPE_VIDEO = "type_video";
private static final String TYPE_PDF = "type_pdf";

2. 可以使用枚举类型代替字符串类型，提高代码的可读性和可维护性：

public enum FileType {
    JPG, PNG, GIF, TIF, BMP, DWG, RFT, PSD, RMVB, FLV, MP4, MPG, WMV, WAV, AVI, PDF
}

public String getTypeName(String url) {
    try {
        String type = FileTypeUtil.getType(new URL(url).openStream());
        FileType fileType = FileType.valueOf(type.toUpperCase());
        switch (fileType) {
            case JPG:
            case PNG:
            case GIF:
            case TIF:
            case BMP:
            case DWG:
            case RFT:
            case PSD:
                return TYPE_IMG;
            case RMVB:
            case FLV:
            case MP4:
            case MPG:
            case WMV:
            case WAV:
            case AVI:
                return TYPE_VIDEO;
            default:
                return TYPE_PDF;
        }
    } catch (Exception e) {
        e.printStackTrace();
        log.error("未找到对应的文件类型！");
    }
    return null;
}

3. 可以使用异常捕获的多态性，避免不必要的异常类型判断：

public String getTypeName(String url) throws IOException {
    try (InputStream inputStream = new URL(url).openStream()) {
        FileType fileType = FileTypeUtil.getType(inputStream);
        switch (fileType) {
            case JPG:
            case PNG:
            case GIF:
            case TIF:
            case BMP:
            case DWG:
            case RFT:
            case PSD:
                return TYPE_IMG;
            case RMVB:
            case FLV:
            case MP4:
            case MPG:
            case WMV:
            case WAV:
            case AVI:
                return TYPE_VIDEO;
            default:
                return TYPE_PDF;
        }
    } catch (IOException e) {
        e.printStackTrace();
        log.error("未找到对应的文件类型！");
        throw e;
    }
}

希望这些优化点能帮到您！