簡單封裝sax的讀取方式，沒有含金量，因為完全沒看懂。。。

只讀第一頁

package com.cuimi.auth.utils;

/* ====================================================================
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.InputStream;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.xml.parsers.ParserConfigurationException;

import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.openxml4j.opc.PackageAccess;
import org.apache.poi.util.SAXHelper;
import org.apache.poi.xssf.eventusermodel.XSSFReader;
import org.apache.poi.xssf.model.SharedStringsTable;
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;

/**
 * XSSF and SAX (Event API) basic example. See {@link XLSX2CSV} for a fuller
 * example of doing XSLX processing with the XSSF Event code.
 */
public class ReadExcelBySAX {
	static List<List<String>> dataList = null;
	static List<String> rowList = null;
	static String flag = "0";// 用於區分 當前的資料是第幾行的

	public void processFirstSheet(String filename) throws Exception {
		try (OPCPackage pkg = OPCPackage.open(filename, PackageAccess.READ)) {
			XSSFReader r = new XSSFReader(pkg);
			SharedStringsTable sst = r.getSharedStringsTable();

			XMLReader parser = fetchSheetParser(sst);

			// process the first sheet
			try (InputStream sheet = r.getSheetsData().next()) {
				InputSource sheetSource = new InputSource(sheet);
				parser.parse(sheetSource);
			}
		}
	}

	// public void processAllSheets(String filename) throws Exception {
	// try (OPCPackage pkg = OPCPackage.open(filename, PackageAccess.READ)) {
	// XSSFReader r = new XSSFReader(pkg);
	// SharedStringsTable sst = r.getSharedStringsTable();
	//
	// XMLReader parser = fetchSheetParser(sst);
	//
	// Iterator<InputStream> sheets = r.getSheetsData();
	// while (sheets.hasNext()) {
	// System.out.println("Processing new sheet:\n");
	// try (InputStream sheet = sheets.next()) {
	// InputSource sheetSource = new InputSource(sheet);
	// parser.parse(sheetSource);
	// }
	// System.out.println("");
	// }
	// }
	// }

	public XMLReader fetchSheetParser(SharedStringsTable sst) throws SAXException, ParserConfigurationException {
		XMLReader parser = SAXHelper.newXMLReader();
		ContentHandler handler = new SheetHandler(sst);
		parser.setContentHandler(handler);
		return parser;
	}

	/**
	 * See org.xml.sax.helpers.DefaultHandler javadocs
	 */
	private static class SheetHandler extends DefaultHandler {
		private final SharedStringsTable sst;
		private String lastContents;
		private boolean nextIsString;
		private boolean inlineStr;
		private final LruCache<Integer, String> lruCache = new LruCache<>(50);

		private static class LruCache<A, B> extends LinkedHashMap<A, B> {
			private final int maxEntries;

			public LruCache(final int maxEntries) {
				super(maxEntries + 1, 1.0f, true);
				this.maxEntries = maxEntries;
			}

			@Override
			protected boolean removeEldestEntry(final Map.Entry<A, B> eldest) {
				return super.size() > maxEntries;
			}
		}

		private SheetHandler(SharedStringsTable sst) {
			this.sst = sst;
		}

		// 獲取結尾的數字
		static String getMatchValue(String str) {
			// 按指定模式在字串查詢
			String pattern = "(\\d+$)";
			// 建立 Pattern 物件
			Pattern r = Pattern.compile(pattern);
			// 現在建立 matcher 物件
			Matcher m = r.matcher(str);
			if (m.find()) {
				return m.group();
			} else {
				return null;
			}
		}

		@Override
		public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException {
			// c => cell
			if (name.equals("c")) {
				// Print the cell reference
				String value = attributes.getValue("r");
				String columnNumber = getMatchValue(value);
				if (CmUtil.isValidString(columnNumber)) {
					if (!flag.equals(columnNumber)) {
						if (!rowList.isEmpty()) {
							dataList.add(rowList);
						}
						rowList = new ArrayList();
						flag = columnNumber;
					}
				}

				// System.out.print(value + " - ");

				// Figure out if the value is an index in the SST
				String cellType = attributes.getValue("t");
				nextIsString = cellType != null && cellType.equals("s");
				inlineStr = cellType != null && cellType.equals("inlineStr");
			}
			// Clear contents cache
			lastContents = "";
		}

		@Override
		public void endElement(String uri, String localName, String name) throws SAXException {
			// Process the last contents as required.
			// Do now, as characters() may be called more than once
			if (nextIsString) {
				Integer idx = Integer.valueOf(lastContents);
				lastContents = lruCache.get(idx);
				if (lastContents == null && !lruCache.containsKey(idx)) {
					lastContents = new XSSFRichTextString(sst.getEntryAt(idx)).toString();
					lruCache.put(idx, lastContents);
				}
				nextIsString = false;
			}

			// v => contents of a cell
			// Output after we've seen the string contents
			if (name.equals("v") || (inlineStr && name.equals("c"))) {
				// System.out.println(lastContents);// 值
				rowList.add(lastContents);
			}
		}

		@Override
		public void characters(char[] ch, int start, int length) throws SAXException { // NOSONAR
			lastContents += new String(ch, start, length);
		}
	}

	public static List<List<String>> getListForExcel(String filePath) {
		dataList = new ArrayList<List<String>>();
		rowList = new ArrayList<String>();

		ReadExcelBySAX howto = new ReadExcelBySAX();
		try {
			howto.processFirstSheet(filePath);
		} catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException("讀取excel資料失敗！");
		}
		return dataList;
	}

	public static void main(String[] args) throws Exception {
		dataList = getListForExcel("H:\\Desktop\\測試.xlsx");
		 System.out.println(dataList);
		// howto.processAllSheets(filename);
	}
}