• EasyExcel的源码流程（导入Excel）

    1. 入口

    2.  EasyExcel类继承了EasyExcelFactory类，EasyExcel自动拥有EasyExcelFactory父类的所有方法，如read()，readSheet()，write()，writerSheet()等等。

    3. 进入.read()方法，需要传入三个参数(文件路径，表头映射类，read监听器)
       首先调用new ExcelReaderBuilder()方法，初始化ReadWorkbook对象
       设置完readWorkbook属性后调，返回excelReaderBuilder对象 

    4. 这里又个传入的参数是read监听器，进入其内部看一下，我们自定义了PersonListener实现了ReadListener。ReadListener接口源码 ：

    自定义的PersonListener类：

    1. import com.alibaba.excel.context.AnalysisContext;
    2. import com.alibaba.excel.event.AnalysisEventListener;
    3. import com.aliyun.odps.jdbc.utils.LoggerFactory;
    4. import org.springframework.stereotype.Component;
    5.  
    6. import java.util.ArrayList;
    7. import java.util.List;
    8. import java.util.Map;
    9. import java.util.logging.Logger;
    10.  
    11. @Component
    12. public class PersonListener extends AnalysisEventListener {
    13.     //一行一行读出excel内容  不读表头  EasyExcel之所以效率高，也是因它一行一行读取，解析。
    14.     @Override
    15.     public void invoke(PersonTest personTest, AnalysisContext analysisContext) {
    16.         System.out.println("***"+personTest);
    17.     }
    18.     //读取表头
    19.     @Override
    20.     public void invokeHeadMap(Map headMap, AnalysisContext context) {
    21.         System.out.println("表头"+headMap);
    22.     }
    23.     //读取完执行的方法
    24.     @Override
    25.     public void doAfterAllAnalysed(AnalysisContext analysisContext) {
    26.         System.out.println("读取全部后执行");
    27.     }
    28. }

    5. 接下来调用的是.sheet()方法，这里我们会传入sheetNo、sheetName参数，调用build()方法创建ExcelReader对象，传入ExcelReaderSheetBuilder构造方法中，最终创ExcelReaderSheetBuilder对象 

    6. 进入build()方法，build()方法生成了ExcelReader对象，初始化ExcelAnalyser，并实例化ExcelAnalyser。

    在实例化ExcelAnalyser时，choiceExcelExecutor()方法通过excel格式使用不同的执行器。
    我们看XLSX中，初始化了XlsxReadContext上下文对象，给到analysisContext，又初始化了XlsxSaxAnalyser解析器对象 

    1. public class ExcelAnalyserImpl implements ExcelAnalyser {
    2.     private static final Logger LOGGER = LoggerFactory.getLogger(ExcelAnalyserImpl.class);
    3.  
    4.     private AnalysisContext analysisContext;
    5.  
    6.     private ExcelReadExecutor excelReadExecutor;
    7.     /**
    8.      * Prevent multiple shutdowns
    9.      */
    10.     private boolean finished = false;
    11.  
    12.     public ExcelAnalyserImpl(ReadWorkbook readWorkbook) {
    13.         try {
    14.             choiceExcelExecutor(readWorkbook);
    15.         } catch (RuntimeException e) {
    16.             finish();
    17.             throw e;
    18.         } catch (Throwable e) {
    19.             finish();
    20.             throw new ExcelAnalysisException(e);
    21.         }
    22.     }
    23.  
    24.     private void choiceExcelExecutor(ReadWorkbook readWorkbook) throws Exception {
    25.         ExcelTypeEnum excelType = ExcelTypeEnum.valueOf(readWorkbook);
    26.         switch (excelType) {
    27.             case XLS:
    28.                 POIFSFileSystem poifsFileSystem;
    29.                 if (readWorkbook.getFile() != null) {
    30.                     poifsFileSystem = new POIFSFileSystem(readWorkbook.getFile());
    31.                 } else {
    32.                     poifsFileSystem = new POIFSFileSystem(readWorkbook.getInputStream());
    33.                 }
    34.                 // So in encrypted excel, it looks like XLS but it's actually XLSX
    35.                 if (poifsFileSystem.getRoot().hasEntry(Decryptor.DEFAULT_POIFS_ENTRY)) {
    36.                     InputStream decryptedStream = null;
    37.                     try {
    38.                         decryptedStream = DocumentFactoryHelper
    39.                             .getDecryptedStream(poifsFileSystem.getRoot().getFileSystem(), readWorkbook.getPassword());
    40.                         XlsxReadContext xlsxReadContext = new DefaultXlsxReadContext(readWorkbook, ExcelTypeEnum.XLSX);
    41.                         analysisContext = xlsxReadContext;
    42.                         excelReadExecutor = new XlsxSaxAnalyser(xlsxReadContext, decryptedStream);
    43.                         return;
    44.                     } finally {
    45.                         IOUtils.closeQuietly(decryptedStream);
    46.                         // as we processed the full stream already, we can close the filesystem here
    47.                         // otherwise file handles are leaked
    48.                         poifsFileSystem.close();
    49.                     }
    50.                 }
    51.                 if (readWorkbook.getPassword() != null) {
    52.                     Biff8EncryptionKey.setCurrentUserPassword(readWorkbook.getPassword());
    53.                 }
    54.                 XlsReadContext xlsReadContext = new DefaultXlsReadContext(readWorkbook, ExcelTypeEnum.XLS);
    55.                 xlsReadContext.xlsReadWorkbookHolder().setPoifsFileSystem(poifsFileSystem);
    56.                 analysisContext = xlsReadContext;
    57.                 excelReadExecutor = new XlsSaxAnalyser(xlsReadContext);
    58.                 break;
    59.             case XLSX:
    60.                 XlsxReadContext xlsxReadContext = new DefaultXlsxReadContext(readWorkbook, ExcelTypeEnum.XLSX);
    61.                 analysisContext = xlsxReadContext;
    62.                 excelReadExecutor = new XlsxSaxAnalyser(xlsxReadContext, null);
    63.                 break;
    64.             case CSV:
    65.                 CsvReadContext csvReadContext = new DefaultCsvReadContext(readWorkbook, ExcelTypeEnum.CSV);
    66.                 analysisContext = csvReadContext;
    67.                 excelReadExecutor = new CsvExcelReadExecutor(csvReadContext);
    68.                 break;
    69.             default:
    70.                 break;
    71.         }
    72.     }
    73. /*
    74. ----------------------------------------略---------------------------------------------
    75. */
    76. }

    7. XlsxSaxAnalyser详解

        7.1 进入new XlsxSaxAnalyser(xlsxReadContext, null)方法看一下,这里使用到SAX模式模式解析excel

    1. public XlsxSaxAnalyser(XlsxReadContext xlsxReadContext, InputStream decryptedStream) throws Exception {
    2.         this.xlsxReadContext = xlsxReadContext;
    3.         // 初始化缓存（cache）
    4.         XlsxReadWorkbookHolder xlsxReadWorkbookHolder = xlsxReadContext.xlsxReadWorkbookHolder();
    5.  
    6.         OPCPackage pkg = readOpcPackage(xlsxReadWorkbookHolder, decryptedStream);
    7.         xlsxReadWorkbookHolder.setOpcPackage(pkg);
    8.  
    9.         // Read the Shared information Strings
    10.         PackagePart sharedStringsTablePackagePart = pkg.getPart(SHARED_STRINGS_PART_NAME);
    11.         if (sharedStringsTablePackagePart != null) {
    12.             // 指定默认缓存
    13.             defaultReadCache(xlsxReadWorkbookHolder, sharedStringsTablePackagePart);
    14.  
    15.             // 分析sharedStringsTable.xml，解析excel所有数据到readCache
    16.             analysisSharedStringsTable(sharedStringsTablePackagePart.getInputStream(), xlsxReadWorkbookHolder);
    17.         }
    18.  
    19.         XSSFReader xssfReader = new XSSFReader(pkg);
    20.         analysisUse1904WindowDate(xssfReader, xlsxReadWorkbookHolder);
    21.  
    22.         // 设置样式表
    23.         setStylesTable(xlsxReadWorkbookHolder, xssfReader);
    24.  
    25.         sheetList = new ArrayList<>();
    26.         sheetMap = new HashMap<>();
    27.         commentsTableMap = new HashMap<>();
    28.         Map packageRelationshipCollectionMap = MapUtils.newHashMap();
    29.         xlsxReadWorkbookHolder.setPackageRelationshipCollectionMap(packageRelationshipCollectionMap);
    30.  
    31.         // 获取所有sheet页
    32.         XSSFReader.SheetIterator ite = (XSSFReader.SheetIterator)xssfReader.getSheetsData();
    33.         int index = 0;
    34.         if (!ite.hasNext()) {
    35.             throw new ExcelAnalysisException("Can not find any sheet!");
    36.         }
    37.         // 遍历sheet页
    38.         while (ite.hasNext()) {
    39.             InputStream inputStream = ite.next();
    40.             // 保存所有sheet页
    41.             sheetList.add(new ReadSheet(index, ite.getSheetName()));
    42.             // 保存所有sheet页的输入流
    43.             sheetMap.put(index, inputStream);
    44.             if (xlsxReadContext.readWorkbookHolder().getExtraReadSet().contains(CellExtraTypeEnum.COMMENT)) {
    45.                 CommentsTable commentsTable = ite.getSheetComments();
    46.                 if (null != commentsTable) {
    47.                     commentsTableMap.put(index, commentsTable);
    48.                 }
    49.             }
    50.             if (xlsxReadContext.readWorkbookHolder().getExtraReadSet().contains(CellExtraTypeEnum.HYPERLINK)) {
    51.                 PackageRelationshipCollection packageRelationshipCollection = Optional.ofNullable(ite.getSheetPart())
    52.                     .map(packagePart -> {
    53.                         try {
    54.                             return packagePart.getRelationships();
    55.                         } catch (InvalidFormatException e) {
    56.                             log.warn("Reading the Relationship failed", e);
    57.                             return null;
    58.                         }
    59.                     }).orElse(null);
    60.                 if (packageRelationshipCollection != null) {
    61.                     packageRelationshipCollectionMap.put(index, packageRelationshipCollection);
    62.                 }
    63.             }
    64.             index++;
    65.         }
    66.     }

        7.2 进入analysisSharedStringsTable方法，可以看到创建了一个SharedStringsTableHandler处理器

        7.3 再进入parseXmlSource看到xmlReader.setContentHandler(handler)这一行代码，设置了SharedStringsTableHandler处理器

    1. private void parseXmlSource(InputStream inputStream, ContentHandler handler) {
    2.         InputSource inputSource = new InputSource(inputStream);
    3.         try {
    4.             SAXParserFactory saxFactory;
    5.             String xlsxSAXParserFactoryName = xlsxReadContext.xlsxReadWorkbookHolder().getSaxParserFactoryName();
    6.             if (StringUtils.isEmpty(xlsxSAXParserFactoryName)) {
    7.                 saxFactory = SAXParserFactory.newInstance();
    8.             } else {
    9.                 saxFactory = SAXParserFactory.newInstance(xlsxSAXParserFactoryName, null);
    10.             }
    11.             try {
    12.                 saxFactory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
    13.             } catch (Throwable ignore) {}
    14.             try {
    15.                 saxFactory.setFeature("http://xml.org/sax/features/external-general-entities", false);
    16.             } catch (Throwable ignore) {}
    17.             try {
    18.                 saxFactory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
    19.             } catch (Throwable ignore) {}
    20.             SAXParser saxParser = saxFactory.newSAXParser();
    21.             XMLReader xmlReader = saxParser.getXMLReader();
    22.             xmlReader.setContentHandler(handler);
    23.             xmlReader.parse(inputSource);
    24.             inputStream.close();
    25.         } catch (IOException | ParserConfigurationException | SAXException e) {
    26.             throw new ExcelAnalysisException(e);
    27.         } finally {
    28.             if (inputStream != null) {
    29.                 try {
    30.                     inputStream.close();
    31.                 } catch (IOException e) {
    32.                     throw new ExcelAnalysisException("Can not close 'inputStream'!");
    33.                 }
    34.             }
    35.         }
    36.     }

        7.4 我们将断点打在SharedStringsTableHandler里，发现下一步进入到这里面的startElement()    starteElement()后会调用endElement()

        7.5 反复调用，excel所有数据读取到readcache中

    8. 调用.doRead()方法，开始SAX解析

        8.1 进入build()方法

        8.2 build()执行完后，执行read()方法，read()里还会进入一次read() 

    9. 调用ExcelAnalyserImpl里的analysis()方法，设置sheetList，并调用执行器开始执行解析 

        9.1 调用的XlsxSaxAnalyser解析器execute()

     10. 进入parseXmlSource()方法，发现和之前的sax差不多，但只两次传入的handler类型不同，还是看一下传入的ContentHandler参数具体实现,进入XlsxRowHandler 内部

    1. public class XlsxRowHandler extends DefaultHandler {
    2.     private final XlsxReadContext xlsxReadContext;
    3.     private static final Map XLSX_CELL_HANDLER_MAP = new HashMap(32);
    4.  
    5.     static {
    6.         CellFormulaTagHandler cellFormulaTagHandler = new CellFormulaTagHandler();
    7.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.CELL_FORMULA_TAG, cellFormulaTagHandler);
    8.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.X_CELL_FORMULA_TAG, cellFormulaTagHandler);
    9.         CellInlineStringValueTagHandler cellInlineStringValueTagHandler = new CellInlineStringValueTagHandler();
    10.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.CELL_INLINE_STRING_VALUE_TAG, cellInlineStringValueTagHandler);
    11.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.X_CELL_INLINE_STRING_VALUE_TAG, cellInlineStringValueTagHandler);
    12.         CellTagHandler cellTagHandler = new CellTagHandler();
    13.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.CELL_TAG, cellTagHandler);
    14.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.X_CELL_TAG, cellTagHandler);
    15.         CellValueTagHandler cellValueTagHandler = new CellValueTagHandler();
    16.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.CELL_VALUE_TAG, cellValueTagHandler);
    17.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.X_CELL_VALUE_TAG, cellValueTagHandler);
    18.         CountTagHandler countTagHandler = new CountTagHandler();
    19.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.DIMENSION_TAG, countTagHandler);
    20.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.X_DIMENSION_TAG, countTagHandler);
    21.         HyperlinkTagHandler hyperlinkTagHandler = new HyperlinkTagHandler();
    22.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.HYPERLINK_TAG, hyperlinkTagHandler);
    23.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.X_HYPERLINK_TAG, hyperlinkTagHandler);
    24.         MergeCellTagHandler mergeCellTagHandler = new MergeCellTagHandler();
    25.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.MERGE_CELL_TAG, mergeCellTagHandler);
    26.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.X_MERGE_CELL_TAG, mergeCellTagHandler);
    27.         RowTagHandler rowTagHandler = new RowTagHandler();
    28.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.ROW_TAG, rowTagHandler);
    29.         XLSX_CELL_HANDLER_MAP.put(ExcelXmlConstants.X_ROW_TAG, rowTagHandler);
    30.     }
    31.  
    32.     public XlsxRowHandler(XlsxReadContext xlsxReadContext) {
    33.         this.xlsxReadContext = xlsxReadContext;
    34.     }
    35.  
    36.     @Override
    37.     public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException {
    38.         XlsxTagHandler handler = XLSX_CELL_HANDLER_MAP.get(name);
    39.         if (handler == null || !handler.support(xlsxReadContext)) {
    40.             return;
    41.         }
    42.         xlsxReadContext.xlsxReadSheetHolder().getTagDeque().push(name);
    43.         handler.startElement(xlsxReadContext, name, attributes);
    44.     }
    45.  
    46.     @Override
    47.     public void characters(char[] ch, int start, int length) throws SAXException {
    48.         String currentTag = xlsxReadContext.xlsxReadSheetHolder().getTagDeque().peek();
    49.         if (currentTag == null) {
    50.             return;
    51.         }
    52.         XlsxTagHandler handler = XLSX_CELL_HANDLER_MAP.get(currentTag);
    53.         if (handler == null || !handler.support(xlsxReadContext)) {
    54.             return;
    55.         }
    56.         handler.characters(xlsxReadContext, ch, start, length);
    57.     }
    58.  
    59.     @Override
    60.     public void endElement(String uri, String localName, String name) throws SAXException {
    61.         XlsxTagHandler handler = XLSX_CELL_HANDLER_MAP.get(name);
    62.         if (handler == null || !handler.support(xlsxReadContext)) {
    63.             return;
    64.         }
    65.         handler.endElement(xlsxReadContext, name);
    66.         xlsxReadContext.xlsxReadSheetHolder().getTagDeque().pop();
    67.     }
    68.  
    69. }

        10.1 startElement()和endElement()都有多种实现

    11. 进入用到的重要的几个类CellTagHandler、RowTagHandler

    CellTagHandler: 读取cell的值，并放入tempCellData

    1. public void startElement(XlsxReadContext xlsxReadContext, String name, Attributes attributes) {
    2.         XlsxReadSheetHolder xlsxReadSheetHolder = xlsxReadContext.xlsxReadSheetHolder();
    3.         xlsxReadSheetHolder.setColumnIndex(PositionUtils.getCol(attributes.getValue(ExcelXmlConstants.ATTRIBUTE_R),
    4.             xlsxReadSheetHolder.getColumnIndex()));
    5.  
    6.         // t="s" ,it means String
    7.         // t="str" ,it means String,but does not need to be read in the 'sharedStrings.xml'
    8.         // t="inlineStr" ,it means String,but does not need to be read in the 'sharedStrings.xml'
    9.         // t="b" ,it means Boolean
    10.         // t="e" ,it means Error
    11.         // t="n" ,it means Number
    12.         // t is null ,it means Empty or Number
    13.         CellDataTypeEnum type = CellDataTypeEnum.buildFromCellType(attributes.getValue(ExcelXmlConstants.ATTRIBUTE_T));
    14.         xlsxReadSheetHolder.setTempCellData(new ReadCellData<>(type));
    15.         xlsxReadSheetHolder.setTempData(new StringBuilder());
    16.  
    17.         // Put in data transformation information
    18.         String dateFormatIndex = attributes.getValue(ExcelXmlConstants.ATTRIBUTE_S);
    19.         int dateFormatIndexInteger;
    20.         if (StringUtils.isEmpty(dateFormatIndex)) {
    21.             dateFormatIndexInteger = DEFAULT_FORMAT_INDEX;
    22.         } else {
    23.             dateFormatIndexInteger = Integer.parseInt(dateFormatIndex);
    24.         }
    25.  
    26.         xlsxReadSheetHolder.getTempCellData().setDataFormatData(
    27.             xlsxReadContext.xlsxReadWorkbookHolder().dataFormatData(dateFormatIndexInteger));
    28.     }
    29.  
    30.     @Override
    31.     public void endElement(XlsxReadContext xlsxReadContext, String name) {
    32.         XlsxReadSheetHolder xlsxReadSheetHolder = xlsxReadContext.xlsxReadSheetHolder();
    33.         ReadCellData tempCellData = xlsxReadSheetHolder.getTempCellData();
    34.         StringBuilder tempData = xlsxReadSheetHolder.getTempData();
    35.         String tempDataString = tempData.toString();
    36.         CellDataTypeEnum oldType = tempCellData.getType();
    37.         switch (oldType) {
    38.             case STRING:
    39.                 // In some cases, although cell type is a string, it may be an empty tag
    40.                 if (StringUtils.isEmpty(tempDataString)) {
    41.                     break;
    42.                 }
    43.                 String stringValue = xlsxReadContext.readWorkbookHolder().getReadCache().get(
    44.                     Integer.valueOf(tempDataString));
    45.                 tempCellData.setStringValue(stringValue);
    46.                 break;
    47.             case DIRECT_STRING:
    48.             case ERROR:
    49.                 tempCellData.setStringValue(tempDataString);
    50.                 tempCellData.setType(CellDataTypeEnum.STRING);
    51.                 break;
    52.             case BOOLEAN:
    53.                 if (StringUtils.isEmpty(tempDataString)) {
    54.                     tempCellData.setType(CellDataTypeEnum.EMPTY);
    55.                     break;
    56.                 }
    57.                 tempCellData.setBooleanValue(BooleanUtils.valueOf(tempData.toString()));
    58.                 break;
    59.             case NUMBER:
    60.             case EMPTY:
    61.                 if (StringUtils.isEmpty(tempDataString)) {
    62.                     tempCellData.setType(CellDataTypeEnum.EMPTY);
    63.                     break;
    64.                 }
    65.                 tempCellData.setType(CellDataTypeEnum.NUMBER);
    66.                 tempCellData.setNumberValue(BigDecimal.valueOf(Double.parseDouble(tempDataString)));
    67.                 break;
    68.             default:
    69.                 throw new IllegalStateException("Cannot set values now");
    70.         }
    71.  
    72.         if (tempCellData.getStringValue() != null
    73.             && xlsxReadContext.currentReadHolder().globalConfiguration().getAutoTrim()) {
    74.             tempCellData.setStringValue(tempCellData.getStringValue().trim());
    75.         }
    76.  
    77.         tempCellData.checkEmpty();
    78.         tempCellData.setRowIndex(xlsxReadSheetHolder.getRowIndex());
    79.         tempCellData.setColumnIndex(xlsxReadSheetHolder.getColumnIndex());
    80.         xlsxReadSheetHolder.getCellMap().put(xlsxReadSheetHolder.getColumnIndex(), tempCellData);
    81.     }

    RowTagHandler: 当一行读取完毕后，调用分析事件处理器，处理一行数据

                                xlsxReadContext.analysisEventProcessor().endRow(xlsxReadContext);

    1. public void startElement(XlsxReadContext xlsxReadContext, String name, Attributes attributes) {
    2.         XlsxReadSheetHolder xlsxReadSheetHolder = xlsxReadContext.xlsxReadSheetHolder();
    3.         int rowIndex = PositionUtils.getRowByRowTagt(attributes.getValue(ExcelXmlConstants.ATTRIBUTE_R),
    4.             xlsxReadSheetHolder.getRowIndex());
    5.         Integer lastRowIndex = xlsxReadContext.readSheetHolder().getRowIndex();
    6.         while (lastRowIndex + 1 < rowIndex) {
    7.             xlsxReadContext.readRowHolder(new ReadRowHolder(lastRowIndex + 1, RowTypeEnum.EMPTY,
    8.                 xlsxReadSheetHolder.getGlobalConfiguration(), new LinkedHashMap()));
    9.             xlsxReadContext.analysisEventProcessor().endRow(xlsxReadContext);
    10.             xlsxReadSheetHolder.setColumnIndex(null);
    11.             xlsxReadSheetHolder.setCellMap(new LinkedHashMap());
    12.             lastRowIndex++;
    13.         }
    14.         xlsxReadSheetHolder.setRowIndex(rowIndex);
    15.     }
    16.  
    17.     @Override
    18.     public void endElement(XlsxReadContext xlsxReadContext, String name) {
    19.         XlsxReadSheetHolder xlsxReadSheetHolder = xlsxReadContext.xlsxReadSheetHolder();
    20.         RowTypeEnum rowType = MapUtils.isEmpty(xlsxReadSheetHolder.getCellMap()) ? RowTypeEnum.EMPTY : RowTypeEnum.DATA;
    21.         // It's possible that all of the cells in the row are empty
    22.         if (rowType == RowTypeEnum.DATA) {
    23.             boolean hasData = false;
    24.             for (Cell cell : xlsxReadSheetHolder.getCellMap().values()) {
    25.                 if (!(cell instanceof ReadCellData)) {
    26.                     hasData = true;
    27.                     break;
    28.                 }
    29.                 ReadCellData readCellData = (ReadCellData)cell;
    30.                 if (readCellData.getType() != CellDataTypeEnum.EMPTY) {
    31.                     hasData = true;
    32.                     break;
    33.                 }
    34.             }
    35.             if (!hasData) {
    36.                 rowType = RowTypeEnum.EMPTY;
    37.             }
    38.         }
    39.         xlsxReadContext.readRowHolder(new ReadRowHolder(xlsxReadSheetHolder.getRowIndex(), rowType,
    40.             xlsxReadSheetHolder.getGlobalConfiguration(), xlsxReadSheetHolder.getCellMap()));
    41.         xlsxReadContext.analysisEventProcessor().endRow(xlsxReadContext);
    42.         xlsxReadSheetHolder.setColumnIndex(null);
    43.         xlsxReadSheetHolder.setCellMap(new LinkedHashMap<>());
    44.     }

    12. 进入endRow()方法

          endRow()里通过getIgnoreEmptyRow()来判断是否忽略空行（true为忽略，默认为true）

         想要设置IgnoreEmptyRow为false，可以在最初使用EasyExcel时设置：

    13. 进入dealData()方法

    1. private void dealData(AnalysisContext analysisContext) {
    2.         ReadRowHolder readRowHolder = analysisContext.readRowHolder();
    3.         Map> cellDataMap = (Map)readRowHolder.getCellMap();
    4.         readRowHolder.setCurrentRowAnalysisResult(cellDataMap);
    5.         int rowIndex = readRowHolder.getRowIndex();
    6.         int currentHeadRowNumber = analysisContext.readSheetHolder().getHeadRowNumber();
    7.  
    8.         boolean isData = rowIndex >= currentHeadRowNumber;
    9.  
    10.         // Last head column
    11.         if (!isData && currentHeadRowNumber == rowIndex + 1) {
    12.             buildHead(analysisContext, cellDataMap);
    13.         }
    14.         // Now is data
    15.         for (ReadListener readListener : analysisContext.currentReadHolder().readListenerList()) {
    16.             try {
    17.                 if (isData) {
    18.                     readListener.invoke(readRowHolder.getCurrentRowAnalysisResult(), analysisContext);
    19.                 } else {
    20.                     readListener.invokeHead(cellDataMap, analysisContext);
    21.                 }
    22.             } catch (Exception e) {
    23.                 onException(analysisContext, e);
    24.                 break;
    25.             }
    26.             if (!readListener.hasNext(analysisContext)) {
    27.                 throw new ExcelAnalysisStopException();
    28.             }
    29.         }
    30.     }

    14. dealData()方法中的invoke方法会执行ModelBuildEventListener里的invoke()方法，在这里会进行单行数据到实体类的映射，buildStringList()真正执行映射

    15. 退回XlsxSaxAnalyser的解析器execute()方法

          进入readComments()方法,读取额外信息（批注、超链接、合并单元格信息读取）

    1. 	private void readComments(ReadSheet readSheet) {
    2.         if (!xlsxReadContext.readWorkbookHolder().getExtraReadSet().contains(CellExtraTypeEnum.COMMENT)) {
    3.             return;
    4.         }
    5.         CommentsTable commentsTable = commentsTableMap.get(readSheet.getSheetNo());
    6.         if (commentsTable == null) {
    7.             return;
    8.         }
    9.         Iterator cellAddresses = commentsTable.getCellAddresses();
    10.         while (cellAddresses.hasNext()) {
    11.             CellAddress cellAddress = cellAddresses.next();
    12.             XSSFComment cellComment = commentsTable.findCellComment(cellAddress);
    13.             CellExtra cellExtra = new CellExtra(CellExtraTypeEnum.COMMENT, cellComment.getString().toString(),
    14.                 cellAddress.getRow(), cellAddress.getColumn());
    15.             xlsxReadContext.readSheetHolder().setCellExtra(cellExtra);
    16.             xlsxReadContext.analysisEventProcessor().extra(xlsxReadContext);
    17.         }
    18.     }

    16. 最后进入.endSheet(xlsxReadContext)方法

    1. @Override
    2.     public void endSheet(AnalysisContext analysisContext) {
    3.     	// 这里会调用所有监听器中的doAfterAllAnalysed方法，执行最后的操作
    4.         for (ReadListener readListener : analysisContext.currentReadHolder().readListenerList()) {
    5.             readListener.doAfterAllAnalysed(analysisContext);
    6.         }
    7.     }

    17. 在读取完毕之后，执行finish()方法，关闭所有流 

  • 相关阅读:
    浮点数通信
    vben-admin 学习记录
    TVS选型：瞬态抑制二极管选型！|深圳比创达EMC
    在Vue3项目中使用pinia代替Vuex进行数据存储
    SpringBoot：（六）YAML配置文件
    python爬虫基于管道持久化存储操作
    SpringBoot 整合Spring Security（简单版）
    服务器动态/静态/住宅/原生IP都是什么意思
    ASP WebShell 后门脚本与免杀
    力扣(LeetCode)75. 颜色分类(C语言)
  • 原文地址：https://blog.csdn.net/qq_44527508/article/details/133296044