大数据excel导入 sax

package com.h3c.oos.util;

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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
							.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();
					// 判断是否是日期格式
					if (HSSFDateUtil.isADateFormat(this.formatIndex, n)) {
						Double d = Double.parseDouble(n);
						Date date = HSSFDateUtil.getJavaDate(d);
						thisStr = formateDateToString(date);
					} else 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;
				}
				// 判断单元格的值是否为空
				if (thisStr == null || "".equals(isCellNull)) {
					isCellNull = true;// 设置单元格是否为空值
				}
				record[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;
					}
					if (isCellNull == false && record[0] != null
							&& record[1] != null)// 判断是否空行
					{
						rows.add(record.clone());
						isCellNull = false;
						for (int i = 0; i < record.length; i++) {
							record[i] = null;
						}
					}
				}
				lastColumnNumber = -1;
			}

		}

		public List<String[]> getRows() {
			return rows;
		}

		public void setRows(List<String[]> rows) {
			this.rows = rows;
		}

		/**
		 * 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 String formateDateToString(Date date) {
			SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");// 格式化日期
			return sdf.format(date);

		}

	}

	// /////////////////////////////////////

	private OPCPackage xlsxPackage;
	private int minColumns;
	private PrintStream output;
	private String sheetName;

	/**
	 * 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 XLSXCovertCSVReader(OPCPackage pkg, PrintStream output,
			String sheetName, int minColumns) {
		this.xlsxPackage = pkg;
		this.output = output;
		this.minColumns = minColumns;
		this.sheetName = sheetName;
	}

	/**
	 * Parses and shows the content of one sheet using the specified styles and
	 * shared-strings tables.
	 * 
	 * @param styles
	 * @param strings
	 * @param sheetInputStream
	 */
	public List<String[]> 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();
		MyXSSFSheetHandler handler = new MyXSSFSheetHandler(styles, strings,
				this.minColumns, this.output);
		sheetParser.setContentHandler(handler);
		sheetParser.parse(sheetSource);
		return handler.getRows();
	}

	/**
	 * 初始化这个处理程序 将
	 * 
	 * @throws IOException
	 * @throws OpenXML4JException
	 * @throws ParserConfigurationException
	 * @throws SAXException
	 */
	public List<String[]> process() throws IOException, OpenXML4JException,
			ParserConfigurationException, SAXException {

		ReadOnlySharedStringsTable strings = new ReadOnlySharedStringsTable(
				this.xlsxPackage);
		XSSFReader xssfReader = new XSSFReader(this.xlsxPackage);
		List<String[]> list = null;
		StylesTable styles = xssfReader.getStylesTable();
		XSSFReader.SheetIterator iter = (XSSFReader.SheetIterator) xssfReader
				.getSheetsData();
		int index = 0;
		while (iter.hasNext()) {
			InputStream stream = iter.next();
			String sheetNameTemp = iter.getSheetName();
			if (this.sheetName.equals(sheetNameTemp)) {
				list = processSheet(styles, strings, stream);
				stream.close();
				++index;
			}
		}
		return list;
	}

	/**
	 * 读取Excel
	 * 
	 * @param path
	 *            文件路径
	 * @param sheetName
	 *            sheet名称
	 * @param minColumns
	 *            列总数
	 * @return
	 * @throws SAXException
	 * @throws ParserConfigurationException
	 * @throws OpenXML4JException
	 * @throws IOException
	 */
	private static List<String[]> readerExcel(String path, String sheetName,
			int minColumns) throws IOException, OpenXML4JException,
			ParserConfigurationException, SAXException {
		OPCPackage p = OPCPackage.open(path, PackageAccess.READ);
		XLSXCovertCSVReader xlsx2csv = new XLSXCovertCSVReader(p, System.out,
				sheetName, minColumns);
		List<String[]> list = xlsx2csv.process();
		p.close();
		return list;
	}

	public static void main(String[] args) throws Exception {
		List<String[]> list = XLSXCovertCSVReader.readerExcel("F:\\test.xlsx", "Sheet1", 17);
		for (String[] record : list) {
			for (String cell : record) {
				System.out.print(cell + "  ");
			}
			System.out.println();
		}
	}

}