feat: 添加文档转PDF转换功能
- 后端添加 PDF 转换服务，支持 Word(docx)、Excel(xlsx)、文本(txt)、Markdown(md) 格式转换为 PDF - 使用 reportlab 库，支持中文字体（simhei.ttf） - 添加 FastAPI 接口：POST /api/v1/pdf/convert 单文件转换，POST /api/v1/pdf/convert/batch 批量转换 - 前端添加 PdfConverter 页面，支持拖拽上传、转换进度显示、批量下载 - 转换流程：所有格式先转为 Markdown，再通过 Markdown 转 PDF，保证输出一致性 - DOCX 解析使用 zipfile 直接读取 XML，避免 python-docx 的兼容性问题的
This commit is contained in:
403
backend/app/services/pdf_converter_service.py
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403
backend/app/services/pdf_converter_service.py
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"""
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PDF 转换服务
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支持将 Word(docx)、Excel(xlsx)、Txt、Markdown(md) 格式转换为 PDF
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策略：所有格式先转为 Markdown，再通过 Markdown 转 PDF
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"""
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import io
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import logging
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import platform
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from pathlib import Path
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from typing import List, Tuple
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from reportlab.lib.pagesizes import A4
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from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
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from reportlab.lib.enums import TA_LEFT, TA_CENTER, TA_JUSTIFY
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from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle
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from reportlab.pdfbase import pdfmetrics
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from reportlab.pdfbase.ttfonts import TTFont
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logger = logging.getLogger(__name__)
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class PDFConverterService:
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"""PDF 转换服务"""
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def __init__(self):
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self.supported_formats = ["docx", "xlsx", "txt", "md"]
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self._font_name = None
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self._styles = None
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self._page_width = None
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self._page_height = None
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self._setup_fonts()
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def _setup_fonts(self):
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"""设置字体"""
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try:
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self._page_width, self._page_height = A4
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# 查找中文字体
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font_path = self._find_chinese_font()
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if font_path:
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try:
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font = TTFont('ChineseFont', font_path)
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pdfmetrics.registerFont(font)
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from reportlab.pdfbase.pdfmetrics import registerFontFamily
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registerFontFamily('ChineseFont', normal='ChineseFont')
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self._font_name = 'ChineseFont'
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logger.info(f"成功注册中文字体: {font_path}")
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except Exception as e:
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logger.warning(f"字体注册失败: {e}, 使用Helvetica")
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self._font_name = 'Helvetica'
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else:
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self._font_name = 'Helvetica'
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logger.warning("未找到中文字体，使用 Helvetica（不支持中文）")
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# 创建样式
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styles = getSampleStyleSheet()
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styles.add(ParagraphStyle(
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name='ChineseTitle',
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fontName=self._font_name,
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fontSize=16,
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leading=22,
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alignment=TA_CENTER,
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spaceAfter=12,
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))
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styles.add(ParagraphStyle(
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name='ChineseHeading',
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fontName=self._font_name,
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fontSize=14,
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leading=20,
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spaceBefore=10,
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spaceAfter=8,
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))
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styles.add(ParagraphStyle(
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name='ChineseBody',
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fontName=self._font_name,
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fontSize=10,
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leading=14,
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alignment=TA_JUSTIFY,
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spaceAfter=6,
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))
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styles.add(ParagraphStyle(
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name='ChineseCode',
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fontName='Courier',
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fontSize=9,
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leading=12,
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))
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self._styles = styles
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logger.info("PDF服务初始化完成")
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except Exception as e:
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logger.error(f"PDF服务初始化失败: {e}")
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raise
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def _find_chinese_font(self) -> str:
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"""查找中文字体"""
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system = platform.system()
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if system == "Windows":
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fonts = [
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"C:/Windows/Fonts/simhei.ttf",
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"C:/Windows/Fonts/simsun.ttc",
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"C:/Windows/Fonts/msyh.ttc",
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"C:/Windows/Fonts/simsun.ttf",
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]
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elif system == "Darwin":
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fonts = [
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"/System/Library/Fonts/STHeiti Light.ttc",
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"/System/Library/Fonts/PingFang.ttc",
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"/Library/Fonts/Arial Unicode.ttf",
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]
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else:
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fonts = [
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"/usr/share/fonts/truetype/wqy/wqy-microhei.ttc",
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"/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc",
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]
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for font in fonts:
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if Path(font).exists():
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return font
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return None
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def _sanitize_text(self, text: str) -> str:
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"""清理文本"""
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if not text:
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return ""
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return text.replace('\x00', '')
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async def convert_to_pdf(
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self,
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file_content: bytes,
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source_format: str,
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filename: str = "document"
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) -> Tuple[bytes, str]:
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"""将文档转换为 PDF"""
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try:
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if source_format.lower() not in self.supported_formats:
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return b"", f"不支持的格式: {source_format}"
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# 第一步：转换为 Markdown
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markdown_content, error = await self._convert_to_markdown(file_content, source_format, filename)
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if error:
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return b"", error
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# 第二步：Markdown 转 PDF
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return await self._convert_markdown_to_pdf(markdown_content, filename)
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except Exception as e:
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logger.error(f"PDF转换失败: {e}")
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import traceback
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logger.error(f"详细错误: {traceback.format_exc()}")
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return b"", f"转换失败: {str(e)}"
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async def _convert_to_markdown(
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self,
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file_content: bytes,
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source_format: str,
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filename: str
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) -> Tuple[str, str]:
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"""将各种格式转换为 Markdown"""
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converters = {
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"docx": self._convert_docx_to_markdown,
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"xlsx": self._convert_xlsx_to_markdown,
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"txt": self._convert_txt_to_markdown,
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"md": self._convert_md_to_markdown,
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}
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return await converters[source_format.lower()](file_content, filename)
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async def _convert_txt_to_markdown(self, file_content: bytes, filename: str) -> Tuple[str, str]:
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"""Txt 转 Markdown"""
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try:
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text = self._decode_content(file_content)
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text = self._sanitize_text(text)
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return f"# {filename}\n\n{text}", ""
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except Exception as e:
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logger.error(f"Txt转Markdown失败: {e}")
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return "", f"文本文件处理失败: {str(e)}"
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async def _convert_md_to_markdown(self, file_content: bytes, filename: str) -> Tuple[str, str]:
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"""Markdown 原样返回"""
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try:
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content = self._decode_content(file_content)
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content = self._sanitize_text(content)
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return f"# {filename}\n\n{content}", ""
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except Exception as e:
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logger.error(f"Markdown处理失败: {e}")
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return "", f"Markdown处理失败: {str(e)}"
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async def _convert_docx_to_markdown(self, file_content: bytes, filename: str) -> Tuple[str, str]:
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"""Word 转 Markdown - 使用 zipfile 直接解析，更加健壮"""
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try:
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import zipfile
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import re
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lines = [f"# {filename}", ""]
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# 直接使用 zipfile 解析 DOCX，避免 python-docx 的严格验证
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try:
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with zipfile.ZipFile(io.BytesIO(file_content), 'r') as zf:
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# 读取主文档内容
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xml_content = zf.read('word/document.xml').decode('utf-8')
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except zipfile.BadZipFile:
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return "", "文件不是有效的 DOCX 格式"
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except KeyError:
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return "", "DOCX 文件损坏：找不到 document.xml"
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# 简单的 XML 解析 - 提取文本段落
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# 移除 XML 标签，提取纯文本
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xml_content = re.sub(r'<w:br[^>]*>', '\n', xml_content)
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xml_content = re.sub(r'</w:p>', '\n', xml_content)
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xml_content = re.sub(r'<[^>]+>', '', xml_content)
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xml_content = re.sub(r'\n\s*\n', '\n\n', xml_content)
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# 解码 HTML 实体
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xml_content = xml_content.replace('&', '&')
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xml_content = xml_content.replace('<', '<')
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xml_content = xml_content.replace('>', '>')
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xml_content = xml_content.replace('"', '"')
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xml_content = xml_content.replace(''', "'")
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# 清理空白
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lines_text = [line.strip() for line in xml_content.split('\n') if line.strip()]
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# 生成 Markdown
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for text in lines_text[:500]: # 限制最多500行
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if text:
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lines.append(text)
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return '\n'.join(lines), ""
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except Exception as e:
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logger.error(f"Word转Markdown失败: {e}")
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import traceback
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logger.error(traceback.format_exc())
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return "", f"Word文档处理失败: {str(e)}"
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for table in doc.tables:
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lines.append("")
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for row in table.rows:
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row_data = [cell.text.strip() for cell in row.cells]
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lines.append("| " + " | ".join(row_data) + " |")
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# 表头分隔符
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if table.rows:
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lines.append("| " + " | ".join(["---"] * len(table.rows[0].cells)) + " |")
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return "\n".join(lines), ""
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except Exception as e:
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logger.error(f"Word转Markdown失败: {e}")
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return "", f"Word文档处理失败: {str(e)}"
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async def _convert_xlsx_to_markdown(self, file_content: bytes, filename: str) -> Tuple[str, str]:
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"""Excel 转 Markdown"""
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try:
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import openpyxl
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wb = openpyxl.load_workbook(io.BytesIO(file_content))
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lines = [f"# {filename} - Excel数据", ""]
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for sheet_name in wb.sheetnames[:10]:
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ws = wb[sheet_name]
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lines.append(f"## 工作表: {sheet_name}")
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lines.append("")
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for row_idx, row in enumerate(ws.iter_rows(max_row=50, values_only=True)):
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row_data = [str(cell) if cell is not None else "" for cell in row]
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if not any(row_data):
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continue
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lines.append("| " + " | ".join(row_data) + " |")
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if row_idx == 0:
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lines.append("| " + " | ".join(["---"] * len(row_data)) + " |")
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lines.append("")
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return "\n".join(lines), ""
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except Exception as e:
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logger.error(f"Excel转Markdown失败: {e}")
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return "", f"Excel处理失败: {str(e)}"
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async def _convert_markdown_to_pdf(self, markdown_content: str, filename: str) -> Tuple[bytes, str]:
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"""Markdown 转 PDF"""
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try:
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logger.info(f"Markdown转PDF开始 - filename={filename}, 字体={self._font_name}")
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logger.info(f"styles['ChineseTitle'].fontName={self._styles['ChineseTitle'].fontName}")
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buffer = io.BytesIO()
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story = []
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safe_filename = self._sanitize_text(filename)
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logger.info(f"safe_filename={repr(safe_filename[:50])}")
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story.append(Paragraph(text=safe_filename, style=self._styles['ChineseTitle']))
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story.append(Spacer(1, 12))
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in_code = False
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for line in markdown_content.split('\n'):
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line = line.strip()
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if line.startswith('```'):
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in_code = not in_code
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story.append(Spacer(1, 6))
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continue
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if in_code:
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story.append(Paragraph(text=self._sanitize_text(line), style=self._styles['ChineseCode']))
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continue
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if not line:
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story.append(Spacer(1, 6))
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continue
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# 标题处理
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if line.startswith('# '):
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story.append(Paragraph(text=self._sanitize_text(line[2:]), style=self._styles['ChineseHeading']))
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elif line.startswith('## '):
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story.append(Paragraph(text=self._sanitize_text(line[3:]), style=self._styles['ChineseHeading']))
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elif line.startswith('### '):
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story.append(Paragraph(text=self._sanitize_text(line[4:]), style=self._styles['ChineseHeading']))
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elif line.startswith('#### '):
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story.append(Paragraph(text=self._sanitize_text(line[5:]), style=self._styles['ChineseHeading']))
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elif line.startswith('- ') or line.startswith('* '):
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story.append(Paragraph(text="• " + self._sanitize_text(line[2:]), style=self._styles['ChineseBody']))
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# 表格处理
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elif line.startswith('|'):
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# 跳过 markdown 表格分隔符
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if set(line.replace('|', '').replace('-', '').replace(':', '').replace(' ', '')) == set():
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continue
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# 解析并创建表格
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table_lines = []
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for _ in range(50): # 最多50行
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if line.startswith('|'):
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row = [cell.strip() for cell in line.split('|')[1:-1]]
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if not any(row) or set(''.join(row).replace('-', '').replace(':', '').replace(' ', '')) == set():
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break
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table_lines.append(row)
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try:
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line = next(markdown_content.split('\n').__iter__()).strip()
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except StopIteration:
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break
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else:
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break
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if table_lines:
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# 创建表格
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t = Table(table_lines, colWidths=[100] * len(table_lines[0]))
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t.setStyle(TableStyle([
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('FONTNAME', (0, 0), (-1, -1), self._font_name),
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('FONTSIZE', (0, 0), (-1, -1), 9),
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('GRID', (0, 0), (-1, -1), 0.5, '#999999'),
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('BACKGROUND', (0, 0), (-1, 0), '#4472C4'),
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('TEXTCOLOR', (0, 0), (-1, 0), '#FFFFFF'),
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]))
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story.append(t)
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story.append(Spacer(1, 6))
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else:
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story.append(Paragraph(text=self._sanitize_text(line), style=self._styles['ChineseBody']))
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logger.info(f"准备构建PDF，story长度={len(story)}")
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pdf_doc = SimpleDocTemplate(
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buffer,
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pagesize=(self._page_width, self._page_height),
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rightMargin=72,
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leftMargin=72,
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topMargin=72,
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bottomMargin=72
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)
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logger.info("调用pdf_doc.build()")
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pdf_doc.build(story)
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logger.info("pdf_doc.build()完成")
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result = buffer.getvalue()
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buffer.close()
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return result, ""
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except Exception as e:
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logger.error(f"Markdown转PDF失败: {e}")
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import traceback
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logger.error(f"详细错误: {traceback.format_exc()}")
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return b"", f"Markdown转PDF失败: {str(e)}"
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def _decode_content(self, file_content: bytes) -> str:
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"""解码文件内容"""
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encodings = ['utf-8', 'gbk', 'gb2312', 'gb18030', 'latin-1']
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for enc in encodings:
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try:
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return file_content.decode(enc)
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except (UnicodeDecodeError, LookupError):
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continue
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return file_content.decode('utf-8', errors='replace')
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def get_supported_formats(self) -> List[str]:
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"""获取支持的格式"""
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return self.supported_formats
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# 全局单例
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pdf_converter_service = PDFConverterService()
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Reference in New Issue
Block a user