使用POI的XSSF和SAX（事件API）读取Excel工作表
我正在阅读使用POI的XSSF和SAX（事件API）的Excel工作表。 Excel工作表拥有数千行用户信息，如用户名，电子邮件，地址，年龄，部门等
我需要从Excel读取每一行，将其转换为一个User对象，并将此User对象添加到一个User对象列表。
我可以成功读取Excel工作表，但是我不知道在阅读的时候我应该创build一个User对象的实例，并使用Excel工作表中的数据填充它。
以下是我的整个工作代码。
import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintStream; import java.util.ArrayList; import java.util.List; import javax.xml.parsers.ParserConfigurationException; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.apache.poi.openxml4j.exceptions.OpenXML4JException; import org.apache.poi.openxml4j.opc.OPCPackage; import org.apache.poi.openxml4j.opc.PackageAccess; import org.apache.poi.ss.usermodel.BuiltinFormats; import org.apache.poi.ss.usermodel.DataFormatter; import org.apache.poi.xssf.eventusermodel.ReadOnlySharedStringsTable; import org.apache.poi.xssf.eventusermodel.XSSFReader; import org.apache.poi.xssf.model.StylesTable; import org.apache.poi.xssf.usermodel.XSSFCellStyle; import org.apache.poi.xssf.usermodel.XSSFRichTextString; import org.xml.sax.Attributes; import org.xml.sax.ContentHandler; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import org.xml.sax.XMLReader; import org.xml.sax.helpers.DefaultHandler; public class ExcelSheetParser { enum xssfDataType { BOOL, ERROR, FORMULA, INLINESTR, SSTINDEX, NUMBER, } int countrows = 0; class XSSFSheetHandler extends DefaultHandler { /** * Table with styles */ private StylesTable stylesTable; /** * Table with unique strings */ private ReadOnlySharedStringsTable sharedStringsTable; /** * Destination for data */ private final PrintStream output; private List<?> list = new ArrayList(); private Class clazz; /** * Number of columns to read starting with leftmost */ private final int minColumnCount; // Set when V start element is seen private boolean vIsOpen; // Set when cell start element is seen; // used when cell close element is seen. private xssfDataType nextDataType; // Used to format numeric cell values. private short formatIndex; private String formatString; private final DataFormatter formatter; private int thisColumn = -1; // The last column printed to the output stream private int lastColumnNumber = -1; // Gathers characters as they are seen. private StringBuffer value; /** * Accepts objects needed while parsing. * * @param styles * Table of styles * @param strings * Table of shared strings * @param cols * Minimum number of columns to show * @param target * Sink for output */ public XSSFSheetHandler(StylesTable styles, ReadOnlySharedStringsTable strings, int cols, PrintStream target, Class clazz) { this.stylesTable = styles; this.sharedStringsTable = strings; this.minColumnCount = cols; this.output = target; this.value = new StringBuffer(); this.nextDataType = xssfDataType.NUMBER; this.formatter = new DataFormatter(); this.clazz = clazz; } public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException { if ("inlineStr".equals(name) || "v".equals(name)) { vIsOpen = true; // Clear contents cache value.setLength(0); } // c => cell else if ("c".equals(name)) { // Get the cell reference String r = attributes.getValue("r"); int firstDigit = -1; for (int c = 0; c < r.length(); ++c) { if (Character.isDigit(r.charAt(c))) { firstDigit = c; break; } } thisColumn = nameToColumn(r.substring(0, firstDigit)); // Set up defaults. this.nextDataType = xssfDataType.NUMBER; this.formatIndex = -1; this.formatString = null; String cellType = attributes.getValue("t"); String cellStyleStr = attributes.getValue("s"); if ("b".equals(cellType)) nextDataType = xssfDataType.BOOL; else if ("e".equals(cellType)) nextDataType = xssfDataType.ERROR; else if ("inlineStr".equals(cellType)) nextDataType = xssfDataType.INLINESTR; else if ("s".equals(cellType)) nextDataType = xssfDataType.SSTINDEX; else if ("str".equals(cellType)) nextDataType = xssfDataType.FORMULA; else if (cellStyleStr != null) { // It's a number, but almost certainly one // with a special style or format int styleIndex = Integer.parseInt(cellStyleStr); XSSFCellStyle style = stylesTable.getStyleAt(styleIndex); this.formatIndex = style.getDataFormat(); this.formatString = style.getDataFormatString(); if (this.formatString == null) this.formatString = BuiltinFormats .getBuiltinFormat(this.formatIndex); } } } public void endElement(String uri, String localName, String name) throws SAXException { String thisStr = null; // v => contents of a cell if ("v".equals(name)) { // Process the value contents as required. // Do now, as characters() may be called more than once switch (nextDataType) { case BOOL: char first = value.charAt(0); thisStr = first == '0' ? "FALSE" : "TRUE"; break; case ERROR: thisStr = "\"ERROR:" + value.toString() + '"'; break; case FORMULA: // A formula could result in a string value, // so always add double-quote characters. thisStr = '"' + value.toString() + '"'; break; case INLINESTR: // TODO: have seen an example of this, so it's untested. XSSFRichTextString rtsi = new XSSFRichTextString(value .toString()); thisStr = '"' + rtsi.toString() + '"'; break; case SSTINDEX: String sstIndex = value.toString(); try { int idx = Integer.parseInt(sstIndex); XSSFRichTextString rtss = new XSSFRichTextString( sharedStringsTable.getEntryAt(idx)); thisStr = '"' + rtss.toString() + '"'; } catch (NumberFormatException ex) { output.println("Failed to parse SST index '" + sstIndex + "': " + ex.toString()); } break; case NUMBER: String n = value.toString(); if (this.formatString != null) thisStr = formatter.formatRawCellContents(Double .parseDouble(n), this.formatIndex, this.formatString); else thisStr = n; break; default: thisStr = "(TODO: Unexpected type: " + nextDataType + ")"; break; } // Output after we've seen the string contents // Emit commas for any fields that were missing on this row if (lastColumnNumber == -1) { lastColumnNumber = 0; } for (int i = lastColumnNumber; i < thisColumn; ++i) output.print(','); // Might be the empty string. output.print(thisColumn +" : "+thisStr); // Update column if (thisColumn > -1) lastColumnNumber = thisColumn; } else if ("row".equals(name)) { // Print out any missing commas if needed if (minColumns > 0) { // Columns are 0 based if (lastColumnNumber == -1) { lastColumnNumber = 0; } for (int i = lastColumnNumber; i < (this.minColumnCount); i++) { output.print(','); } } // We're onto a new row output.println(); output.println(countrows++); lastColumnNumber = -1; } } /** * Captures characters only if a suitable element is open. Originally * was just "v"; extended for inlineStr also. */ public void characters(char[] ch, int start, int length) throws SAXException { if (vIsOpen) value.append(ch, start, length); } /** * Converts an Excel column name like "C" to a zero-based index. * * @param name * @return Index corresponding to the specified name */ private int nameToColumn(String name) { int column = -1; for (int i = 0; i < name.length(); ++i) { int c = name.charAt(i); column = (column + 1) * 26 + c - 'A'; } return column; } } // ///////////////////////////////////// private OPCPackage xlsxPackage; private int minColumns; private PrintStream output; private Class clazz; /** * Creates a new XLSX -> CSV converter * * @param pkg * The XLSX package to process * @param output * The PrintStream to output the CSV to * @param minColumns * The minimum number of columns to output, or -1 for no minimum */ public ExcelSheetParser(OPCPackage pkg, PrintStream output, int minColumns, Class clazz) { this.xlsxPackage = pkg; this.output = output; this.minColumns = minColumns; this.clazz = clazz; } /** * Parses and shows the content of one sheet using the specified styles and * shared-strings tables. * * @param styles * @param strings * @param sheetInputStream */ public void processSheet(StylesTable styles, ReadOnlySharedStringsTable strings, InputStream sheetInputStream) throws IOException, ParserConfigurationException, SAXException { InputSource sheetSource = new InputSource(sheetInputStream); SAXParserFactory saxFactory = SAXParserFactory.newInstance(); SAXParser saxParser = saxFactory.newSAXParser(); XMLReader sheetParser = saxParser.getXMLReader(); ContentHandler handler = new XSSFSheetHandler(styles, strings, this.minColumns, this.output, this.clazz); sheetParser.setContentHandler(handler); sheetParser.parse(sheetSource); } /** * Initiates the processing of the XLS workbook file to CSV. * * @throws IOException * @throws OpenXML4JException * @throws ParserConfigurationException * @throws SAXException */ public void process() throws IOException, OpenXML4JException, ParserConfigurationException, SAXException { ReadOnlySharedStringsTable strings = new ReadOnlySharedStringsTable( this.xlsxPackage); XSSFReader xssfReader = new XSSFReader(this.xlsxPackage); StylesTable styles = xssfReader.getStylesTable(); XSSFReader.SheetIterator iter = (XSSFReader.SheetIterator) xssfReader .getSheetsData(); int index = 0; while (iter.hasNext()) { InputStream stream = iter.next(); String sheetName = iter.getSheetName(); this.output.println(sheetName + " [index=" + index + "]:"); processSheet(styles, strings, stream); stream.close(); ++index; } } } 我可能做的是开始build立用户对象，当行开始。 当你击中行中的单元格时，填充你的用户对象。 当行结束时，validation用户对象，如果没问题，那么就添加它。 因为你正在做SAXparsing，你会得到所有这些的开始和事件，所以你可以在那里附加你的逻辑。
我build议你看看Apache POI示例中的XLSX2CSV 。 它展示了如何处理不同types的单元格内容（您需要填充用户对象），到达行尾时如何处理，以及如何处理丢失的单元格等。
我认为你可以在你的代码中的以下位置创build一个用户对象：
// We're onto a new row output.println(); // Convert output to a new user object // .... // ....
首先在thisStrvariables中保存值，如果这是一个有效的值，那么把这个值放在Map中。
你应该在endElement（）方法中创buildUSer对象
else if ("row".equals(name)) { // use map create USER object here }
您可以将用户对象添加到全局列表中，并且如果要保留它，则可以一次一页地存储用户对象或所有数据。
while (iter.hasNext()) { InputStream stream = iter.next(); String sheetName = iter.getSheetName(); this.output.println(sheetName + " [index=" + index + "]:"); processSheet(styles, strings, stream); stream.close(); ++index; //for persisting USERS data sheet by sheet write your code here......... } // for persisting complete data of all sheets write your code here...
这是为我工作。
对于我的一个项目，我创build了一个使用Apache POI和OpenCSV的基本实用程序，可以读取xlsx，xls和csv文件。
给定一个转换器，它可以将行转换为对象，如下所示：
RowConverter<Country> converter = (row) -> new Country(row[0], row[1]); ExcelReader<Country> reader = ExcelReader.builder(Country.class) .converter(converter) .withHeader() .csvDelimiter(';') .sheets(1) .build(); List<Country> list; list = reader.read("CountryCodes.xlsx"); list = reader.read("CountryCodes.xls"); list = reader.read("CountryCodes.csv");
你可以在github上find这个项目。