java实现在线预览--poi实现word、excel、ppt转html
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，
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，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。
