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(/)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/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 mons.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 mons.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。