大数据excel导入 sax

package com.h3c.oos.util;

/* ==================================================================== 
 Licensed to the Apache Software Foundation (ASF) under one or more 
 contributor license agreements.  See the NOTICE file distributed with 
 this work for additional information regarding copyright ownership. 
 The ASF licenses this file to You under the Apache License, Version 2.0 
 (the "License"); you may not use this file except in compliance with 
 the License.  You may obtain a copy of the License at 

 http://www.apache.org/licenses/LICENSE-2.0 

 Unless required by applicable law or agreed to in writing, software 
 distributed under the License is distributed on an "AS IS" BASIS, 
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 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 
 Also see
	 * Standard ECMA-376, 1st edition, part 4, pages 1928ff, at
	 * http://www.ecma-international.org/publications/standards/Ecma-376.htm
	 * 
 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 rows = new ArrayList();
		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 getRows() {
			return rows;
		}

		public void setRows(List 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 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 process() throws IOException, OpenXML4JException,
			ParserConfigurationException, SAXException {

		ReadOnlySharedStringsTable strings = new ReadOnlySharedStringsTable(
				this.xlsxPackage);
		XSSFReader xssfReader = new XSSFReader(this.xlsxPackage);
		List 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 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 list = xlsx2csv.process();
		p.close();
		return list;
	}

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

}