DWR 3.0 上传文件

conkeyn · 发表于 2013-1-23 02:23:35

第一步：需要文件包，其实就是dwr 3.0中例子所需要的包，dwr.jar、commons-fileupload-1.2.jar、commons-io-1.3.1.jar。

第二步：编辑web.xml，添加dwr-invoke
<servlet><display-name>DWR Sevlet</display-name><servlet-name>dwr-invoker</servlet-name><servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class><init-param><description>是否打开调试功能</description><param-name>debug</param-name><param-value>true</param-value></init-param><init-param><description>日志级别有效值为： FATAL, ERROR, WARN (the default), INFO and DEBUG.</description><param-name>logLevel</param-name><param-value>DEBUG</param-value></init-param><init-param><description>是否激活反向Ajax</description><param-name>activeReverseAjaxEnabled</param-name><param-value>true</param-value></init-param><init-param>    <description>在WEB启动时是否创建范围为application的creator</description>    <param-name>initApplicationScopeCreatorsAtStartup</param-name>    <param-value>true</param-value>  </init-param>  <init-param><description>在WEB启动时是否创建范围为application的creator</description>    <param-name>preferDataUrlSchema</param-name> <param-value>false</param-value> </init-param> <load-on-startup>1</load-on-startup>  </servlet><servlet-mapping><servlet-name>dwr-invoker</servlet-name><url-pattern>/dwr/*</url-pattern></servlet-mapping> 第三步：创建上传类FileUpload.java，编辑代码，内容如下：
package learn.dwr.upload_download;import java.awt.Color;import java.awt.Font;import java.awt.Graphics2D;import java.awt.geom.AffineTransform;import java.awt.image.AffineTransformOp;import java.awt.image.BufferedImage;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import org.directwebremoting.WebContext;import org.directwebremoting.WebContextFactory;/** * title: 文件上传 * @author Administrator * @时间 2009-11-22:上午11:40:22 */public class FileUpload {/** * @param uploadImage 圖片文件流 * @param uploadFile 需要用简单的文本文件，如：.txt文件，不然上传会出乱码 * @param color * @return */public BufferedImage uploadFiles(BufferedImage uploadImage,String uploadFile, String color) {// uploadImage = scaleToSize(uploadImage);// uploadImage =grafitiTextOnImage(uploadImage, uploadFile, color);return uploadImage;}/** * 文件上传时使用InputStream类进行接收，在DWR官方例中是使用String类接收简单内容 *  * @param uploadFile * @return */public String uploadFile(InputStream uploadFile, String filename)throws Exception {WebContext webContext = WebContextFactory.get();String realtivepath = webContext.getContextPath() + "/upload/";String saveurl = webContext.getHttpServletRequest().getSession().getServletContext().getRealPath("/upload");File file = new File(saveurl + "/" + filename);// if (!file.exists()) {// file.mkdirs();// }int available = uploadFile.available();byte[] b = new byte[available];FileOutputStream foutput = new FileOutputStream(file);uploadFile.read(b);foutput.write(b);foutput.flush();foutput.close();uploadFile.close();return realtivepath + filename;}private BufferedImage scaleToSize(BufferedImage uploadImage) {AffineTransform atx = new AffineTransform();atx.scale(200d / uploadImage.getWidth(), 200d / uploadImage.getHeight());AffineTransformOp atfOp = new AffineTransformOp(atx,AffineTransformOp.TYPE_BILINEAR);uploadImage = atfOp.filter(uploadImage, null);return uploadImage;}private BufferedImage grafitiTextOnImage(BufferedImage uploadImage,String uploadFile, String color) {if (uploadFile.length() < 200) {uploadFile += uploadFile + " ";}Graphics2D g2d = uploadImage.createGraphics();for (int row = 0; row < 10; row++) {String output = "";if (uploadFile.length() > (row + 1) * 20) {output += uploadFile.substring(row * 20, (row + 1) * 20);} else {output = uploadFile.substring(row * 20);}g2d.setFont(new Font("SansSerif", Font.BOLD, 16));g2d.setColor(Color.blue);g2d.drawString(output, 5, (row + 1) * 20);}return uploadImage;}} 第四步：添加到dwr.xml
<create creator="new"><param name="class" value="learn.dwr.upload_download.FileUpload" /></create> 第五步：添加前台html代码
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>二进制文件处理，文件上传</title><script type='text/javascript' src='/learnajax/dwr/interface/FileUpload.js'></script><script type='text/javascript' src='/learnajax/dwr/engine.js'></script><script type='text/javascript' src='/learnajax/dwr/util.js'></script><script type='text/javascript' >function uploadFiles(){var uploadImage = dwr.util.getValue("uploadImage"); FileUpload.uploadFiles(uploadImage, "", "", function(imageURL) {alert(imageURL); dwr.util.setValue('image', imageURL);  });}function uploadFile(){var uploadFile = dwr.util.getValue("uploadFile");//var uploadFile =document.getElementById("uploadFile").value;var uploadFile_temp = uploadFile.value.replace("\\","/");var filenames = uploadFile.value.split("/");var filename = filenames[filenames.length-1];//var extension = e[e.length-1];FileUpload.uploadFile(uploadFile,filename,function(data){var file_a= document.getElementById("file_a");file_a.href=data;file_a.innerHTML=data;document.getElementById("filediv").style.display="";});}</script></head><body><table border="1" cellpadding="3" width="50%"><tr> <td>Image</td>       <td><input type="file" id="uploadImage" /></td>       <td><input type="button"  value="upload"/><div id="image.container">&nbsp;</div></td> </tr> <tr> <td>File</td>       <td><input type="file" id="uploadFile" /></td>       <td><input type="button"  value="upload"/><div id="file.container">&nbsp;</div></td> </tr> <tr> <td colspan="3"></td> </tr></table><img id="image" src="javascript:void(0);"/><div id="filediv" style="display:none;"><a href="" id="file_a">上传的文件</a></div></body></html> 添加进度条么，就需要用reverse ajax 进行配合使用了。

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