excel导入大数据失败解决方法

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See the License for the specific language governing permissions and limitations under the License. ==================================================================== */ import java.io.IOException; import java.io.InputStream; import java.io.PrintStream; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.List; import javax.xml.parsers.ParserConfigurationException; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.apache.poi.hssf.usermodel.HSSFDateUtil; 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.InputSource; import org.xml.sax.SAXException; import org.xml.sax.XMLReader; import org.xml.sax.helpers.DefaultHandler; /** * 使用CVS模式解决XLSX文件，可以有效解决用户模式内存溢出的问题 * 该模式是POI官方推荐的读取大数据的模式，在用户模式下，数据量较大、Sheet较多、或者是有很多无用的空行的情况 * ，容易出现内存溢出,用户模式读取Excel的典型代码如下： FileInputStream file=new * FileInputStream("c:\\test.xlsx"); Workbook wb=new XSSFWorkbook(file); * * * @author 山人 */ public class XLSXCovertCSVReader { /** * The type of the data value is indicated by an attribute on the cell. The * value is usually in a "v" element within the cell. */ enum xssfDataType { BOOL, ERROR, FORMULA, INLINESTR, SSTINDEX, NUMBER, } /** * 使用xssf_sax_API处理Excel,请参考： http://poi.apache.org/spreadsheet/how-to.html#xssf_sax_api * <p/> * Also see Standard ECMA-376, 1st edition, part 4, pages 1928ff, at * http://www.ecma-international.org/publications/standards/Ecma-376.htm * <p/> * A web-friendly version is http://openiso.org/Ecma/376/Part4 */ class MyXSSFSheetHandler extends DefaultHandler { /** * Table with styles */ private StylesTable stylesTable; /** * Table with unique strings */ private ReadOnlySharedStringsTable sharedStringsTable; /** * Destination for data */ private final PrintStream output; /** * 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; private String[] record; private List<String[]> rows = new ArrayList<String[]>(); private boolean isCellNull = false; /** * 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 MyXSSFSheetHandler(StylesTable styles, ReadOnlySharedStringsTable strings, int cols, PrintStream target) { this.stylesTable = styles; this.sharedStringsTable = strings; this.minColumnCount = cols; this.output = target; this.value = new StringBuffer(); this.nextDataType = xssfDataType.NUMBER; this.formatter = new DataFormatter(); record = new String[this.minColumnCount]; rows.clear();// 每次读取都清空行集合 } /* * (non-Javadoc) * * @see * org.xml.sax.helpers.DefaultHandler#startElement(java.lang.String, * java.lang.String, java.lang.String, org.xml.sax.Attributes) */ 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); } } } /* * (non-Javadoc) * * @see org.xml.sax.helpers.DefaultHandler#endElement(java.lang.String, * java.lang.String, java.lang.String) */ 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.toSt