/// <summary>
/// 通过PDF文档对象解析PDF
/// </summary>
/// <param name="pdfDocument">PDF文档</param>
/// <param name="tableContainType">表格包含样式</param>
/// <returns></returns>
public static PDFModel Parser(PDDocument pdfDocument, TableContainType tableContainType)
{
ObjectExtractor extractor = new ObjectExtractor(pdfDocument);
PageIterator pageIterator = extractor.extract();
SpreadsheetExtractionAlgorithm tableExtractor = new SpreadsheetExtractionAlgorithm();
PDFModel pdfModel = new PDFModel();
PDFTextStripper pdfStripper = new PDFTextStripper();
pdfStripper.setPageEnd(pageEndMark);
//pdfStripper.setParagraphEnd(paragraphEndMark);
string[] strs = Regex.Split(pdfStripper.getText(pdfDocument), pageEndMark, RegexOptions.IgnoreCase);
if (strs != null && strs.Length > 0)
{
pdfModel.Pages = new List <PdfPageModel>();
int cp = 0;
while (pageIterator.hasNext())
{
PdfPageModel pdfPage = new PdfPageModel();
pdfPage.CurrentPage = cp + 1;
pdfPage.Text = strs[cp];
List <Table> tables = new List <Table>();
Page page = pageIterator.next();
var pageTables = tableExtractor.extract(page).toArray();
if (pageTables != null && pageTables.Length > 0)
{
for (int i = 0; i < pageTables.Length; i++)
{
tables.Add(pageTables[i] as Table);
}
}
pdfPage.Tables = tables;
pdfModel.Pages.Add(pdfPage);
cp++;
}
pdfModel.PageNumber = pdfModel.Pages.Count;
return(PdfTextFormater(pdfModel, tableContainType));
}
return(null);
}
/// <summary>
/// 对PDF解析出的文字进行格式化，去掉页眉，页脚，页码，可识别的表格，并尝试在对分页后的数据进行拼接；
/// 对常用的指代与冒号分割的进行表格化或Json化；
/// 表格提供方便显示的CSV格式载入和方便机器计算的Json加载模式；
/// </summary>
/// <param name="pdf">结构化后的PDF</param>
/// <returns></returns>
protected static PDFModel PdfTextFormater(PDFModel pdf, TableContainType tableContainType)
{
StringBuilder sbFileContent = new StringBuilder();
string fileContent = string.Empty;
//猜测非空行的最大长度区间, 统计所有行的字数，去除小于5的部分，获取平均数作为可能的最小非换行字数
int minLineCount = 25;
List <int> countList = new List <int>();
if (pdf.PageNumber > 0 && pdf.Pages != null)
{
//1. 循环所有的页，提取去除前后空格后的文字，使用分隔符将文字分隔为数组
Dictionary <string, ContentRemoveTag> maybeBeginText = new Dictionary <string, ContentRemoveTag>();
Dictionary <string, ContentRemoveTag> maybeEndText = new Dictionary <string, ContentRemoveTag>();
List <TagPosition> needRemovePage = new List <TagPosition>();
for (int page = 1; page <= pdf.Pages.Count; page++)
{
PdfPageModel pdfPageModel = pdf.Pages[page - 1];
//使用换行符拆分字符串
string[] pageTexts = lineRegex.Split(pdfPageModel.Text);
List <int> tempCountList = pageTexts.Select(f => f.Replace(" ", "").Replace(" ", "").Replace("\r", "").Replace("\n", "").Length).Where(f => f > 15).ToList();
if (tempCountList != null && tempCountList.Count > 0)
{
countList.AddRange(tempCountList);
}
//获取非空字符串的前三行和后三行的文字部分
int beginGetCount = 0;
int endGetCount = 0;
for (int i = 0; i < pageTexts.Length; i++)
{
if (beginGetCount < 3)
{
TagPosition tagPosition = new TagPosition();
tagPosition.PageNumber = page;
tagPosition.LineNumber = i;
string _cleanText = pageTexts[i].Replace(" ", "").Replace(" ", "").Replace("\r", "").Replace("\n", "");
if (!string.IsNullOrWhiteSpace(_cleanText))
{
int numberCount = NumberOfDigits(_cleanText);
//去掉单行单个数字的行，同时去除分页前后的换行。
if (numberCount == _cleanText.Length && numberCount < 10 && numberCount >= 1)
{
needRemovePage.Add(tagPosition);
}
else
{
if (maybeBeginText.ContainsKey(_cleanText))
{
maybeBeginText[_cleanText].OccurCount++;
maybeBeginText[_cleanText].tagPositions.Add(tagPosition);
}
else
{
maybeBeginText[_cleanText] = new ContentRemoveTag();
maybeBeginText[_cleanText].Content = _cleanText;
maybeBeginText[_cleanText].OccurCount++;
maybeBeginText[_cleanText].tagPositions = new List <TagPosition>();
maybeBeginText[_cleanText].tagPositions.Add(tagPosition);
}
beginGetCount++;
}
}
else if (beginGetCount == 0)
{
needRemovePage.Add(tagPosition);
}
}
if (endGetCount < 3)
{
TagPosition tagPosition = new TagPosition();
tagPosition.PageNumber = page;
tagPosition.LineNumber = pageTexts.Length - i - 1;
string _cleanText = pageTexts[pageTexts.Length - i - 1].Replace(" ", "").Replace(" ", "").Replace("\r", "").Replace("\n", "");
if (!string.IsNullOrWhiteSpace(_cleanText))
{
int numberCount = NumberOfDigits(_cleanText);
//去掉单行单个数字的行，同时去除分页前后的换行。
if (numberCount == _cleanText.Length && numberCount < 10 && numberCount >= 1)
{
needRemovePage.Add(tagPosition);
}
else
{
if (maybeEndText.ContainsKey(_cleanText))
{
maybeEndText[_cleanText].OccurCount++;
maybeEndText[_cleanText].tagPositions.Add(tagPosition);
}
else
{
maybeEndText[_cleanText] = new ContentRemoveTag();
maybeEndText[_cleanText].Content = _cleanText;
maybeEndText[_cleanText].OccurCount++;
maybeEndText[_cleanText].tagPositions = new List <TagPosition>();
maybeEndText[_cleanText].tagPositions.Add(tagPosition);
}
endGetCount++;
}
}
else if (endGetCount == 0)
{
needRemovePage.Add(tagPosition);
}
}
}
}
//比较和记录出现的频率
foreach (var _beginItem in maybeBeginText.Values)
{
if (_beginItem.OccurCount > 2 && _beginItem.OccurCount >= (pdf.Pages.Count - 2))
{
needRemovePage.AddRange(_beginItem.tagPositions);
}
}
foreach (var _endItem in maybeEndText.Values)
{
if (_endItem.OccurCount > 2 && _endItem.OccurCount >= (pdf.Pages.Count - 2))
{
needRemovePage.AddRange(_endItem.tagPositions);
}
}
if (countList != null && countList.Count > 0)
{
minLineCount = Math.Min(countList.Sum() / countList.Count, 30);
}
//2. 对段落进行合并和返回
int currentTablePos = 0;
bool isTableStarted = false;
bool lastIsEnd = true;
for (int page = 1; page <= pdf.Pages.Count; page++)
{
//处理上一页遗留的表格数据
if (isTableStarted && page > 1)
{
PdfPageModel lastPdfPageModel = pdf.Pages[page - 2];
if (lastPdfPageModel.Tables != null && lastPdfPageModel.Tables.Count > currentTablePos)
{
string lastTableStr = TableWriter.ToString(lastPdfPageModel.Tables[currentTablePos], tableContainType);
//sbFileContent.AppendLine(tableStartMark);
sbFileContent.AppendLine(lastTableStr.Replace("\r", "").Replace("\n", "\r\n"));
//sbFileContent.AppendLine(tableEndMark);
}
}
PdfPageModel pdfPageModel = pdf.Pages[page - 1];
string[] pageTexts = lineRegex.Split(pdfPageModel.Text);
//对表格进行结构化
List <string> tableStrs = new List <string>();
if (pdfPageModel.Tables != null && pdfPageModel.Tables.Count > 0)
{
foreach (Table table in pdfPageModel.Tables)
{
try
{
tableStrs.Add(TableWriter.ToString(table, tableContainType));
}
catch { }
}
}
currentTablePos = 0;
isTableStarted = false;
//bool needCleanMenu = false;
//清理需要清理的行，并进行合并
for (int i = 0; i < pageTexts.Length; i++)
{
//忽略页码行数据
if (needRemovePage.Any(f => f.PageNumber == page && f.LineNumber == i))
{
lastIsEnd = true;
continue;
}
string cleanText = pageTexts[i];
bool isMatchTable = false;
//判断当前页的表格是否包含，存在的情况将表格列替换为表格位置标识的形式，后续替换为CSV或JSON
tableGuess:
if (tableStrs != null && tableStrs.Count > currentTablePos)
{
if (!string.IsNullOrWhiteSpace(cleanText))
{
string tableStr = tableStrs[currentTablePos];
string[] words = Regex.Split(cleanText, @"[^\u4e00-\u9fa5a-zA-z0-9]+");
if (words != null && words.Length > 0)
{
foreach (var word in words)
{
if (string.IsNullOrWhiteSpace(word))
{
continue;
}
if (tableStr.Contains(word))
{
isMatchTable = true;
continue;
}
else
{
isMatchTable = false;
break;
}
}
}
if (isMatchTable)
{
isTableStarted = true;
continue;
}
if (isTableStarted && !isMatchTable)
{
//sbFileContent.AppendLine(tableStartMark);
sbFileContent.AppendLine(tableStr.Replace("\r", "").Replace("\n", "\r\n"));
//sbFileContent.AppendLine(tableEndMark);
lastIsEnd = true;
isTableStarted = false;
currentTablePos++;
goto tableGuess;
}
}
}
//忽略目录部分的数据
string onlyText = cleanText.Replace(" ", "").Replace(" ", "").Replace("\r", "").Replace("\n", "");
if (onlyText == "目录" || onlyText.ToUpper() == "MENU")
{
//needCleanMenu = true;
continue;
}
//if (needCleanMenu)
{
if (string.IsNullOrWhiteSpace(onlyText) || Regex.IsMatch(onlyText, @".*?(\.{6,}\s*\d+)\s*"))
{
continue;
}
//else
// needCleanMenu = false;
}
//判断是否以正常中止标点符号结尾
bool endWithStopFlag = cleanText.EndsWith("。") || cleanText.EndsWith("！") || cleanText.EndsWith("：") || cleanText.EndsWith("；");
//判断该行是否包含正文常见标点符号
bool includeNormalFlag = Regex.IsMatch(cleanText, @"[！；，。“]");
//统计非空格字数
int _lineCount = onlyText.Length;
//判断该行字数是否大于最小行字数
bool isLenThanMinLineCount = _lineCount >= minLineCount;
bool firstException = false;
//特例一：存在明显的排序性质的行，如 ◆，（一），■ 等
if (cleanText.StartsWith("◆") || cleanText.StartsWith("■") || cleanText.StartsWith("（"))
{
firstException = true;
}
//特例二：该行存在：的情况，较大可能是一段的开始
if (!endWithStopFlag && !includeNormalFlag && !isLenThanMinLineCount && (cleanText.Contains(":") || cleanText.Contains("：")))
{
firstException = true;
}
//情景一：该行是一段的结尾，加上段落的文字后换行
if (!firstException && endWithStopFlag)
{
sbFileContent.Append(cleanText);
lastIsEnd = true;
}
//情景二：该行是普通的一行，并未结束
else if (!firstException && !endWithStopFlag && isLenThanMinLineCount)
{
sbFileContent.Append(cleanText);
lastIsEnd = false;
}
//情景三：该行是独立行
else if (lastIsEnd && (firstException || (!isLenThanMinLineCount && !endWithStopFlag && !includeNormalFlag)))
{
sbFileContent.AppendLine(cleanText);
lastIsEnd = true;
}
//情景四：该行为独立的段落
else
{
sbFileContent.AppendLine(cleanText);
lastIsEnd = true;
}
}
}
}
//去掉首尾的换行
fileContent = sbFileContent.ToString().Trim('\r', '\n', ' ', '\t');
pdf.Text = fileContent;
return(pdf);
}