java实现在线预览
- -之poi实现word、excel、ppt转html
###简介

java实现在线预览功能是一个大家在工作中也许会遇到的需求，如果公司有钱，直接使用付费的第三方软件或者云在线预览服务就可以了，例如永中office、office web 365(http://www.officeweb365.com/)他们都有云在线预览服务，就是要钱0.0

如果想要免费的，可以用openoffice，还需要借助其他的工具(例如swfTools、FlexPaper等)才行，可参考这篇文章http://blog.csdn.net/z69183787/article/details/17468039，写的挺细的，实现原理就是：

1.通过第三方工具openoffice，将word、excel、ppt、txt等文件转换为pdf文件；

2.通过swfTools将pdf文件转换成swf格式的文件；

3.通过FlexPaper文档组件在页面上进行展示。

当然如果装了Adobe Reader XI，那把pdf直接拖到浏览器页面就可以直接打开预览，这样就不需要步骤2、3了，前提就是客户装了Adobe Reader XI这个pdf阅读器。

我这里介绍通过poi实现word、excel、ppt转html，这样就可以放在页面上了。
###word转html
package wordToHtml;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.List;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.apache.commons.io.FileUtils;
import org.apache.poi.hwpf.HWPFDocument;
import org.apache.poi.hwpf.converter.PicturesManager;
import org.apache.poi.hwpf.converter.WordToHtmlConverter;
import org.apache.poi.hwpf.usermodel.Picture;
import org.apache.poi.hwpf.usermodel.PictureType;
import org.w3c.dom.Document;
public class PoiWordToHtml {
 public static void main(String[] args) throws Throwable {
  final String path = "D:\\poi-test\\wordToHtml\\";
  final String file = "人员选择系分.doc";
  InputStream input = new FileInputStream(path + file);
  HWPFDocument wordDocument = new HWPFDocument(input);
  WordToHtmlConverter wordToHtmlConverter = new WordToHtmlConverter(
    DocumentBuilderFactory.newInstance().newDocumentBuilder()
      .newDocument());
  wordToHtmlConverter.setPicturesManager(new PicturesManager() {
   public String savePicture(byte[] content, PictureType pictureType,
     String suggestedName, float widthInches, float heightInches) {
    return suggestedName;
   }
  });
  wordToHtmlConverter.processDocument(wordDocument);
  List pics = wordDocument.getPicturesTable().getAllPictures();
  if (pics != null) {
   for (int i = 0; i < pics.size(); i++) {
    Picture pic = (Picture) pics.get(i);
    try {
     pic.writeImageContent(new FileOutputStream(path
       + pic.suggestFullFileName()));
    } catch (FileNotFoundException e) {
     e.printStackTrace();
    }
   }
  }
  Document htmlDocument = wordToHtmlConverter.getDocument();
  ByteArrayOutputStream outStream = new ByteArrayOutputStream();
  DOMSource domSource = new DOMSource(htmlDocument);
  StreamResult streamResult = new StreamResult(outStream);
  TransformerFactory tf = TransformerFactory.newInstance();
  Transformer serializer = tf.newTransformer();
  serializer.setOutputProperty(OutputKeys.ENCODING, "utf-8");
  serializer.setOutputProperty(OutputKeys.INDENT, "yes");
  serializer.setOutputProperty(OutputKeys.METHOD, "html");
  serializer.transform(domSource, streamResult);
  outStream.close();
  String content = new String(outStream.toByteArray());
  FileUtils.writeStringToFile(new File(path, "人员选择系分.html"), content, "utf-8");
 }
}

###excel转html
package excelToHtml;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.apache.commons.io.FileUtils;
import org.apache.poi.hssf.converter.ExcelToHtmlConverter;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hwpf.converter.PicturesManager;
import org.apache.poi.hwpf.converter.WordToHtmlConverter;
import org.apache.poi.hwpf.usermodel.Picture;
import org.apache.poi.hwpf.usermodel.PictureType;
import org.w3c.dom.Document;


public class PoiExcelToHtml {
	final static String path = "D:\\poi-test\\excelToHtml\\";
	 final static String file = "exportExcel.xls";
 public static void main(String args[]) throws Exception {
	 
	 InputStream input=new FileInputStream(path+file);
	 HSSFWorkbook excelBook=new HSSFWorkbook(input);
	 ExcelToHtmlConverter excelToHtmlConverter = new ExcelToHtmlConverter (DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument() );
	 excelToHtmlConverter.processWorkbook(excelBook);
	 List pics = excelBook.getAllPictures();
     if (pics != null) {
         for (int i = 0; i < pics.size(); i++) {
             Picture pic = (Picture) pics.get (i);
             try {
                 pic.writeImageContent (new FileOutputStream (path + pic.suggestFullFileName() ) );
             } catch (FileNotFoundException e) {
                 e.printStackTrace();
             }
         }
     }
     Document htmlDocument =excelToHtmlConverter.getDocument();
     ByteArrayOutputStream outStream = new ByteArrayOutputStream();
     DOMSource domSource = new DOMSource (htmlDocument);
     StreamResult streamResult = new StreamResult (outStream);
     TransformerFactory tf = TransformerFactory.newInstance();
     Transformer serializer = tf.newTransformer();
     serializer.setOutputProperty (OutputKeys.ENCODING, "utf-8");
     serializer.setOutputProperty (OutputKeys.INDENT, "yes");
     serializer.setOutputProperty (OutputKeys.METHOD, "html");
     serializer.transform (domSource, streamResult);
     outStream.close();

     String content = new String (outStream.toByteArray() );

     FileUtils.writeStringToFile(new File (path, "exportExcel.html"), content, "utf-8");
 }
}

###ppt转html

其实只是ppt转图片，有了图片后放到页面上去，点击下一页就一张张显示就可以了。这里只介绍ppt转图片的过程。
package pptToImg;

import java.awt.Dimension;   
import java.io.File;   
import java.io.FileInputStream;   
import java.io.FileNotFoundException;   
import java.io.FileOutputStream;   
import java.io.IOException;   
  
import java.awt.Color;   
import java.awt.Dimension;   
import java.awt.Graphics2D;   
import java.awt.geom.Rectangle2D;   
import java.awt.image.BufferedImage;   
  
import org.apache.poi.hslf.model.TextRun;   
import org.apache.poi.hslf.record.Slide;   
import org.apache.poi.hslf.usermodel.RichTextRun;   
import org.apache.poi.hslf.usermodel.SlideShow;   
  
public class PPTtoImage {   
    public static void main(String[] args) {   
        // 读入PPT文件   
        File file = new File("D:/poi-test/pptToImg/test.ppt");   
        doPPTtoImage(file);   
    }   
  
    public static boolean doPPTtoImage(File file) {   
        boolean isppt = checkFile(file);   
        if (!isppt) {   
            System.out.println("The image you specify don't exit!");   
            return false;   
        }   
        try {   
  
            FileInputStream is = new FileInputStream(file);   
            SlideShow ppt = new SlideShow(is);   
            is.close();   
            Dimension pgsize = ppt.getPageSize();   
            org.apache.poi.hslf.model.Slide[] slide = ppt.getSlides();   
            for (int i = 0; i < slide.length; i++) {   
                System.out.print("第" + i + "页。");   
                   
                TextRun[] truns = slide[i].getTextRuns();      
                for ( int k=0;k<truns.length;k++){      
                   RichTextRun[] rtruns = truns[k].getRichTextRuns();      
                  for(int l=0;l<rtruns.length;l++){      
                       int index = rtruns[l].getFontIndex();      
                        String name = rtruns[l].getFontName();                
                        rtruns[l].setFontIndex(1);      
                        rtruns[l].setFontName("宋体");  
//                        System.out.println(rtruns[l].getText());
                   }      
                }      
                BufferedImage img = new BufferedImage(pgsize.width,pgsize.height, BufferedImage.TYPE_INT_RGB);   
  
                Graphics2D graphics = img.createGraphics();   
                graphics.setPaint(Color.BLUE);   
                graphics.fill(new Rectangle2D.Float(0, 0, pgsize.width, pgsize.height));   
                slide[i].draw(graphics);   
  
                // 这里设置图片的存放路径和图片的格式(jpeg,png,bmp等等),注意生成文件路径   
                FileOutputStream out = new FileOutputStream("D:/poi-test/pptToImg/pict_"+ (i + 1) + ".jpeg");   
                javax.imageio.ImageIO.write(img, "jpeg", out);   
                out.close();   
  
            }   
            System.out.println("success!!");   
            return true;   
        } catch (FileNotFoundException e) {   
            System.out.println(e);   
            // System.out.println("Can't find the image!");   
        } catch (IOException e) {   
        }   
        return false;   
    }   
  
    // function 检查文件是否为PPT   
    public static boolean checkFile(File file) {   
  
        boolean isppt = false;   
        String filename = file.getName();   
        String suffixname = null;   
        if (filename != null && filename.indexOf(".") != -1) {   
            suffixname = filename.substring(filename.indexOf("."));   
            if (suffixname.equals(".ppt")) {   
                isppt = true;   
            }   
            return isppt;   
        } else {   
            return isppt;   
        }   
    }   
  
}  

ppt转图片有个缺陷，就是ppt里不是宋体的字有些可能会变成框框。

以上都需要引入poi的jar包。

要实现在线预览，只需把转换得到的html在新标签页打开或者镶嵌到某块区域就可以展现了。

poi 两种模式
1.用户模式
一次性加载excel(xml文档以一棵DOM树的形式存放在内存中) 数据量大会OOM
2.SAX模式(XSSF and SAX（event API）)
逐行读取xml解析(excel有03和07两种版本，两个版本数据存储方式截然不同，sax解析方式也各不一样 api复杂不利于实现)
EasyExcel
官网

https://www.yuque.com/easyexcel/doc/easyexcel

原理

1.对poi的封装和改版

2.文件解压文件读取通过文件形式(通过磁盘可以减少内存的使用)

3.采用sax模式一行一行解析，并将一行的解析结果以观察者的模式通知处理

4.抛弃不重要的数据(样式，字体，宽度)

使用这套API操作Excel时,将对Excel进行全程锁定,所以不能有其他程序访问同一文件.
package poi;
 
import java.io.FileOutputStream;
import java.util.Calendar;
import java.util.Date;
 
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFDataFormat;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.HSSFColor;
 
public class App {
 
    public static void main(String[] args) {
        try {
            FileOutputStream fos = new FileOutputStream("d:/poi.xls");
            // 建立工作空间
            HSSFWorkbook wb = new HSSFWorkbook();
            // 创建工作表
            HSSFSheet sheet = wb.createSheet("first Sheet");
            wb.createSheet("second Sheet");
            // 创建行
            HSSFRow row = sheet.createRow(0);
            // 创建单元格
            HSSFCell cell = row.createCell(0);
            // 设置不同的值进行比较
            cell.setCellValue(true);// boolean
            row.createCell(1).setCellValue(Calendar.getInstance());// 日历类型
            row.createCell(2).setCellValue(new Date());// date类型
            row.createCell(3).setCellValue(123456789.987654321);// double
            String str = "sadfasdfsadfsadfsdddddddddddffffffffffffffffdsadf";
            row.createCell(4).setCellValue(new HSSFRichTextString(str));// String
 
            // 格式化单元格数据
            HSSFCellStyle style = wb.createCellStyle();// 创建样式对象
            HSSFDataFormat format = wb.createDataFormat();// 创建数据格式对象
            style.setDataFormat(format.getFormat("yyyy-MM-dd hh:mm:ss"));
            row.getCell(1).setCellStyle(style);
            row.getCell(2).setCellStyle(style);
 
            style = wb.createCellStyle();
            style.setDataFormat(format.getFormat("#,###.0000"));
            row.getCell(3).setCellStyle(style);
 
            // 设置列宽,单位int:是点的1/20
            sheet.setColumnWidth(1, 5000);
            sheet.autoSizeColumn((short) 2);// 自动列宽
            sheet.autoSizeColumn((short) 4);
 
            // 设置文本的对齐方式
            row = sheet.createRow(1);
            row.createCell(0).setCellValue(new HSSFRichTextString("左上"));
            row.createCell(1).setCellValue(new HSSFRichTextString("中中"));
            row.createCell(2).setCellValue(new HSSFRichTextString("右下"));
            // #左上
            style = wb.createCellStyle();
            style.setAlignment(HSSFCellStyle.ALIGN_LEFT);// 水平左
            style.setVerticalAlignment(HSSFCellStyle.VERTICAL_TOP);// 水平左
            row.getCell(0).setCellStyle(style);
            // #中中
            style = wb.createCellStyle();
            style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
            style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
            row.getCell(1).setCellStyle(style);
            // #左上
            style = wb.createCellStyle();
            style.setAlignment(HSSFCellStyle.ALIGN_RIGHT);
            style.setVerticalAlignment(HSSFCellStyle.VERTICAL_BOTTOM);
            row.getCell(2).setCellStyle(style);
 
            // 行高
            row.setHeight((short) 2000);
 
            // 字体颜色和大小
            HSSFFont font = wb.createFont();
            font.setFontHeightInPoints((short) 30);// 字体高度
            font.setItalic(true);// 斜体
            font.setColor(HSSFColor.RED.index);// 字体颜色
 
            style = row.getCell(0).getCellStyle();
            style.setFont(font);// 为单元格样式应用字体
            sheet.setColumnWidth(0, (short) 5000);
 
            // 设置旋转
            style.setRotation((short) 60);
 
            // 设置边框样式
            row = sheet.createRow(2);
            cell = row.createCell(0);
            style = wb.createCellStyle();
            style.setTopBorderColor(HSSFColor.RED.index);// 上边框
            style.setBorderTop(HSSFCellStyle.BORDER_MEDIUM_DASH_DOT_DOT);
            cell.setCellStyle(style);
 
            // 计算列
            row = sheet.createRow(3);
            row.createCell(0).setCellValue(12);
            row.createCell(1).setCellValue(13);
            row.createCell(2).setCellValue(14);
 
            cell = row.createCell(3);
            cell.setCellFormula("average(A4:C4)");
 
            row = sheet.createRow(4);
            row.createCell(0).setCellValue(22);
            row.createCell(1).setCellValue(23);
            row.createCell(2).setCellValue(24);
            cell = row.createCell(3);
            cell.setCellFormula("sum(A4:C5)");
 
            // 整体移动行
            // sheet.shiftRows(2, 4, -1);
 
            // 拆分窗格
            // 1000:x轴拆分距离 2000:y轴拆分距离
            // 1:右侧窗格开始显示的列的索引数 2:下策窗口开始显示的行的索引的数
            // 2:哪个面板去激活
            // sheet.createSplitPane(1000, 2000, 1, 2, 2);
 
            // 冻结窗格
            // 1:冻结的列数 2:冻结行数 3:右侧窗格从第几列开始显示 4:下侧窗格从第几行开始显示
            // sheet.createFreezePane(1, 2, 3, 4);
            wb.write(fos);
            fos.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Apache POI 与 Alibaba EasyExcel 的使用




Apache POI

<dependencies>
  	<!-- xls(03) -->
  	<dependency>
  		<groupId>org.apache.poi</groupId>
  		<artifactId>poi</artifactId>
  		<version>3.9</version>
  	</dependency>
  	<!-- xls(07) -->
  	<dependency>
  		<groupId>org.apache.poi</groupId>
  		<artifactId>poi-ooxml</artifactId>
  		<version>3.9</version>
  	</dependency>
  	<!-- 日期格式化工具 -->
  	<dependency>
  		<groupId>joda-time</groupId>
  		<artifactId>joda-time</artifactId>
  		<version>2.10.1</version>
  	</dependency>
  	<dependency>
  		<groupId>junit</groupId>
  		<artifactId>junit</artifactId>
  		<version>4.12</version>
  	</dependency>
</dependencies>


测试写（03版）

String Path = "D:\\data\\";

@Test
public void testWrite03() throws Exception {
	// 创建工作簿对象 03
	Workbook workbook = new HSSFWorkbook();
	// 创建一个工作表
	Sheet sheet0 = workbook.createSheet("BLU测试表");
	// 创建一行
	Row row0 = sheet0.createRow(0);
	// 创建一个单元格
	Cell cell00 = row0.createCell(0);
	cell00.setCellValue("编号");
	Cell cell01 = row0.createCell(1);
	cell01.setCellValue("姓名");
	Row row1 = sheet0.createRow(1);
	Cell cell10 = row1.createCell(0);
	cell10.setCellValue(1);
	Cell cell11 = row1.createCell(1);
	cell11.setCellValue("BLU");
	Cell cell12 = row1.createCell(2);
	String time = new DateTime().toString("yyyy-MM-dd HH:mm:ss");
	cell12.setCellValue(time);
	FileOutputStream fos = new FileOutputStream(Path + "test03.xls");
	workbook.write(fos);
	fos.close();
	System.out.println("文件生成完毕");
}



测试写（07版）

String Path = "D:\\data\\";

@Test
public void testWrite07() throws Exception {
	Workbook workbook = new XSSFWorkbook();
	Sheet sheet0 = workbook.createSheet("BLU测试表");
	Row row0 = sheet0.createRow(0);
	Cell cell00 = row0.createCell(0);
	cell00.setCellValue("编号");
	Cell cell01 = row0.createCell(1);
	cell01.setCellValue("姓名");
	Row row1 = sheet0.createRow(1);
	Cell cell10 = row1.createCell(0);
	cell10.setCellValue(1);
	Cell cell11 = row1.createCell(1);
	cell11.setCellValue("BLU");
	Cell cell12 = row1.createCell(2);
	String time = new DateTime().toString("yyyy-MM-dd HH:mm:ss");
	cell12.setCellValue(time);
	FileOutputStream fos = new FileOutputStream(Path + "test07.xlsx");
	workbook.write(fos);
	fos.close();
	System.out.println("文件生成完毕");
}



测试大数据写入（03版）

String Path = "D:\\data\\";
	
/**
 * 65536行数据耗时：2.815s 
 * 最多只能创建65536行
 */
	
@Test
public void testWrite03BigData() throws Exception {
	long begin = System.currentTimeMillis();
	HSSFWorkbook workbook = new HSSFWorkbook();
	Sheet sheet = workbook.createSheet();
	for (int rowNum = 0; rowNum < 65536; rowNum++) {
		Row row = sheet.createRow(rowNum);
		for (int cellNum = 0; cellNum < 10; cellNum++) {
			Cell cell = row.createCell(cellNum);
			cell.setCellValue(cellNum);
		}
	}
	System.out.println("over");
	FileOutputStream fos = new FileOutputStream(Path + "testWrite03BigData.xls");
	workbook.write(fos);
	fos.close();
	long end = System.currentTimeMillis();
	System.out.println((double) (end - begin) / 1000);
}


测试大数据写入（07版）

String Path = "D:\\data\\";

/**
 * 65536行数据耗时6.843s
 * 10万行数据耗时13.028s
 * 内存占用大
 */
	 
@Test
public void testWrite07BigData() throws Exception {
	long begin = System.currentTimeMillis();
	XSSFWorkbook workbook = new XSSFWorkbook();
	Sheet sheet = workbook.createSheet();
	for (int rowNum = 0; rowNum < 100000; rowNum++) {
		Row row = sheet.createRow(rowNum);
		for (int cellNum = 0; cellNum < 10; cellNum++) {
			Cell cell = row.createCell(cellNum);
			cell.setCellValue(cellNum);
		}
	}
	System.out.println("over");
	FileOutputStream fos = new FileOutputStream(Path + "testWrite07BigData.xlsx");
	workbook.write(fos);
	fos.close();
	long end = System.currentTimeMillis();
	System.out.println((double) (end - begin) / 1000);

}


使用 SXSSFWorkbook 测试大数据写入

String Path = "D:\\data\\";

/**
 * 10万行数据耗时1.916s
 */

@Test
public void testWrite07BigDataS() throws Exception {
	long begin = System.currentTimeMillis();
	SXSSFWorkbook workbook = new SXSSFWorkbook();
	Sheet sheet = workbook.createSheet();
	for (int rowNum = 0; rowNum < 100000; rowNum++) {
		Row row = sheet.createRow(rowNum);
		for (int cellNum = 0; cellNum < 10; cellNum++) {
			Cell cell = row.createCell(cellNum);
			cell.setCellValue(cellNum);
		}
	}
	System.out.println("over");
	FileOutputStream fos = new FileOutputStream(Path + "testWrite07BigDataS.xlsx");
	workbook.write(fos);
	fos.close();
	// 清除临时文件
	workbook.dispose();
	long end = System.currentTimeMillis();
	System.out.println((double) (end - begin) / 1000);
}


测试读（03版）

String Path = "D:\\data\\";

@Test
public void testRead03() throws Exception {
	FileInputStream fis = new FileInputStream(Path + "test03.xls");
	Workbook workbook = new HSSFWorkbook(fis);
	Sheet sheet = workbook.getSheetAt(0);
	Row row = sheet.getRow(1);
	Cell cell0 = row.getCell(0);
	double value0 = cell0.getNumericCellValue();
	System.out.println(value0);
	Cell cell1 = row.getCell(1);
	String value1 = cell1.getStringCellValue();
	System.out.println(value1);
	fis.close();
}

1.0
BLU


测试读（07版）

String Path = "D:\\data\\";

@Test
public void testRead07() throws Exception {
	FileInputStream fis = new FileInputStream(Path + "test07.xlsx");
	Workbook workbook = new XSSFWorkbook(fis);
	Sheet sheet = workbook.getSheetAt(0);
	Row row = sheet.getRow(1);
	Cell cell0 = row.getCell(0);
	double value0 = cell0.getNumericCellValue();
	System.out.println(value0);
	Cell cell1 = row.getCell(1);
	String value1 = cell1.getStringCellValue();
	System.out.println(value1);
	fis.close();
}

1.0
BLU


根据数据类型读取的示例：

BLU.xls文件：


String Path = "D:\\data\\";

@Test
public void testCellType() throws Exception {
	FileInputStream fis = new FileInputStream(Path + "BLU.xls");
	Workbook workbook = new HSSFWorkbook(fis);
	Sheet sheet = workbook.getSheetAt(0);
	Row rowTitle = sheet.getRow(0);
	if (rowTitle != null) {
		int cellCount = rowTitle.getPhysicalNumberOfCells();
		for (int cellNum = 0; cellNum < cellCount; cellNum++) {
			Cell cell = rowTitle.getCell(cellNum);
			if (cell != null) {
				String cellValue = cell.getStringCellValue();
				System.out.print(cellValue + " | ");
			}
		}
	}
	System.out.println();
	int rowCount = sheet.getPhysicalNumberOfRows();
	for (int rowNum = 1; rowNum < rowCount; rowNum++) {
		Row rowData = sheet.getRow(rowNum);
		if (rowData != null) {
			int cellCount = rowData.getPhysicalNumberOfCells();
			for (int cellNum = 0; cellNum < cellCount; cellNum++) {
				Cell cell = rowData.getCell(cellNum);
				if (cell != null) {
					int cellType = cell.getCellType();
					switch (cellType) {
					case HSSFCell.CELL_TYPE_STRING:
						System.out.print(cell.getStringCellValue());
						break;
					case HSSFCell.CELL_TYPE_BOOLEAN:
						System.out.print(String.valueOf(cell.getBooleanCellValue()));
						break;
					case HSSFCell.CELL_TYPE_BLANK:
						break;
					case HSSFCell.CELL_TYPE_NUMERIC:
						if(HSSFDateUtil.isCellDateFormatted(cell)) {
							Date date = cell.getDateCellValue();
							String s = new DateTime(date).toString("yyyy-MM-dd");
							System.out.print(s);
						}else {
							cell.setCellType(HSSFCell.CELL_TYPE_STRING);
							System.out.print(cell.toString());
						}
						break;
					case HSSFCell.CELL_TYPE_ERROR:
						break;
					}
					System.out.print(" | ");
				}
			}
			System.out.println();
		}
	}
	fis.close();
}

手机号 | 日期 | 订单号 | 商品编号 | 商品名称 | 价格 | 销售数量 | 销售金额 | 已发货 | 
15651776666 | 2020-09-30 | 000001 | 1 | 蒙牛 | 65.5 | 1 | 65.5 | true | 
15651776666 | 2020-10-01 | 000002 | 2 | 脑白金 | 100 | 10 | 1000 | false | 


读取计算函数的示例：

func.xls文件：


String Path = "D:\\data\\";

@Test
public void testFormula() throws Exception {
	FileInputStream fis = new FileInputStream(Path + "func.xls");
	Workbook workbook = new HSSFWorkbook(fis);
	Sheet sheet = workbook.getSheetAt(0);
	Row row = sheet.getRow(4);
	Cell cell = row.getCell(0);
	FormulaEvaluator formulaEvaluator = new HSSFFormulaEvaluator((HSSFWorkbook) workbook);
	int cellType = cell.getCellType();
	switch(cellType) {
	case Cell.CELL_TYPE_FORMULA:
		String formula = cell.getCellFormula();
		System.out.println(formula);
		CellValue evaluate = formulaEvaluator.evaluate(cell);
		String cellValue = evaluate.formatAsString();
		System.out.println(cellValue);
		break;
	}

}

SUM(A2:A4)
600.0



Alibaba EasyExcel

<dependencies>
  	<dependency>
  		<groupId>com.alibaba</groupId>
  		<artifactId>easyexcel</artifactId>
  		<version>2.2.0-beta2</version>
  	</dependency>
  <!-- 日期格式化工具 -->
  <dependency>
  	<groupId>joda-time</groupId>
  	<artifactId>joda-time</artifactId>
  	<version>2.10.1</version>
  </dependency>
  <dependency>
  	<groupId>org.projectlombok</groupId>
  	<artifactId>lombok</artifactId>
  	<version>1.18.12</version>
  </dependency>
  <dependency>
  	<groupId>com.alibaba</groupId>
  	<artifactId>fastjson</artifactId>
  	<version>1.2.62</version>
  </dependency>
  <dependency>
  	<groupId>junit</groupId>
  	<artifactId>junit</artifactId>
  	<version>4.12</version>
  </dependency>	
 </dependencies>


实体类：

package com.blu.easy;

import java.util.Date;
import com.alibaba.excel.annotation.ExcelIgnore;
import com.alibaba.excel.annotation.ExcelProperty;
import lombok.Data;

@Data
public class DemoData {
    @ExcelProperty("字符串标题")
    private String string;
    @ExcelProperty("日期标题")
    private Date date;
    @ExcelProperty("数字标题")
    private Double doubleData;
    /**
     * 忽略这个字段
     */
    @ExcelIgnore
    private String ignore;
}


监听器：

package com.blu.easy;


import java.util.ArrayList;
import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.alibaba.fastjson.JSON;

public class DemoDataListener extends AnalysisEventListener<DemoData> {
	
    private static final Logger LOGGER = LoggerFactory.getLogger(DemoDataListener.class);
    private static final int BATCH_COUNT = 5;
    List<DemoData> list = new ArrayList<DemoData>();

    private DemoDAO demoDAO;
    
    public DemoDataListener() {
        demoDAO = new DemoDAO();
    }

    public DemoDataListener(DemoDAO demoDAO) {
        this.demoDAO = demoDAO;
    }
    
    @Override
    public void invoke(DemoData data, AnalysisContext context) {
    	System.out.println(JSON.toJSONString(data));
        list.add(data);
        // 达到BATCH_COUNT了，需要去存储一次数据库，防止数据几万条数据在内存，容易OOM
        if (list.size() >= BATCH_COUNT) {
            saveData();
            // 存储完成清理 list
            list.clear();
        }
    }
    /**
     * 所有数据解析完成了 都会来调用
     *
     * @param context
     */
    @Override
    public void doAfterAllAnalysed(AnalysisContext context) {
        // 这里也要保存数据，确保最后遗留的数据也存储到数据库
        saveData();
        LOGGER.info("所有数据解析完成！");
    }
    /**
     * 加上存储数据库
     */
    private void saveData() {
        LOGGER.info("{}条数据，开始存储数据库！", list.size());
        demoDAO.save(list);
        LOGGER.info("存储数据库成功！");
    }
}


DAO：

package com.blu.easy;

import java.util.List;

/**
 * 假设这个是你的DAO存储。当然还要这个类让spring管理，当然你不用需要存储，也不需要这个类。
 **/
public class DemoDAO {
    public void save(List<DemoData> list) {
    	// 持久化操作
        // 如果是mybatis,尽量别直接调用多次insert,自己写一个mapper里面新增一个方法batchInsert,所有数据一次性插入
    }
}


测试：

package com.blu.easy;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import org.junit.Test;

import com.alibaba.excel.EasyExcel;

public class EasyTest {
	
	String Path = "D:\\data\\";
	
	private List<DemoData> data() {
        List<DemoData> list = new ArrayList<DemoData>();
        for (int i = 0; i < 10; i++) {
            DemoData data = new DemoData();
            data.setString("字符串" + i);
            data.setDate(new Date());
            data.setDoubleData(0.56);
            list.add(data);
        }
        return list;
    }
	
	/**
     * 最简单的写
     */
    @Test
    public void simpleWrite() {
        String fileName = Path + "easyTest.xlsx";
        EasyExcel.write(fileName, DemoData.class).sheet("模板").doWrite(data());

    }
    
    /**
     * 最简单的读
     */
    @Test
    public void simpleRead() {
        // 有个很重要的点 DemoDataListener 不能被spring管理，要每次读取excel都要new,然后里面用到spring可以构造方法传进去
    	String fileName = Path + "easyTest.xlsx";
        // 这里 需要指定读用哪个class去读，然后读取第一个sheet 文件流会自动关闭
        EasyExcel.read(fileName, DemoData.class, new DemoDataListener()).sheet().doRead();
    }

}

写入结果：



读取结果：
{"date":1601434567000,"doubleData":0.56,"string":"字符串0"}
{"date":1601434567000,"doubleData":0.56,"string":"字符串1"}
{"date":1601434567000,"doubleData":0.56,"string":"字符串2"}
{"date":1601434567000,"doubleData":0.56,"string":"字符串3"}
{"date":1601434567000,"doubleData":0.56,"string":"字符串4"}
{"date":1601434567000,"doubleData":0.56,"string":"字符串5"}
{"date":1601434567000,"doubleData":0.56,"string":"字符串6"}
{"date":1601434567000,"doubleData":0.56,"string":"字符串7"}
{"date":1601434567000,"doubleData":0.56,"string":"字符串8"}
{"date":1601434567000,"doubleData":0.56,"string":"字符串9"}