java實現在線預覽--poi實現word、excel、ppt轉html

java實現在線預覽

- -之poi實現word、excel、ppt轉html

###簡介
java實現在線預覽功能是一個大家在工作中也許會遇到的需求，如果公司有錢，直接使用付費的第三方軟件或者雲在線預覽服務就可以了，例如永中office、office web 365(http://www.officeweb365.com/)他們都有云在線預覽服務，就是要錢0.0
如果想要免費的，可以用openoffice，還需要藉助其他的工具(例如swfTools、FlexPaper等)才行，可參考這篇文章http://blog.csdn.net/z69183787/article/details/17468039，寫的挺細的，實現原理就是：
1.通過第三方工具openoffice，將word、excel、ppt、txt等文件轉換爲pdf文件；
2.通過swfTools將pdf文件轉換成swf格式的文件；
3.通過FlexPaper文檔組件在頁面上進行展示。
當然如果裝了Adobe Reader XI，那把pdf直接拖到瀏覽器頁面就可以直接打開預覽，這樣就不需要步驟2、3了，前提就是客戶裝了Adobe Reader XI這個pdf閱讀器。
我這裏介紹通過poi實現word、excel、ppt轉html，這樣就可以放在頁面上了。

###word轉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 = "人員選擇系分.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, "人員選擇系分.html"), content, "utf-8");
 }
}

###excel轉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轉html
其實只是ppt轉圖片，有了圖片後放到頁面上去，點擊下一頁就一張張顯示就可以了。這裏只介紹ppt轉圖片的過程。

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) {   
        // 讀入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 + "頁。");   
                   
                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("宋體");  
//                        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);   
  
                // 這裏設置圖片的存放路徑和圖片的格式(jpeg,png,bmp等等),注意生成文件路徑   
                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 檢查文件是否爲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轉圖片有個缺陷，就是ppt裏不是宋體的字有些可能會變成框框。
以上都需要引入poi的jar包。
要實現在線預覽，只需把轉換得到的html在新標籤頁打開或者鑲嵌到某塊區域就可以展現了。