java文件上传

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所需Jar包

commons.fileupload-1.2.0.jar、commons.logging-1.1.1.jar、commons.beanutils-1.8.0.jar、commons.collections-3.2.0.jar、commons.io-1.4.0.jar、commons.lang-2.1.0.jar

实现效果

代码实现

首先编写核心代码，Javascript打开上传页面，并且从上传页获取返回参数，最后数据返回给回调函数callback：

<script>.......function openUpload_(){openUpload(null,'JPG,GIF,JPEG,PNG','5',callback);}/** * 回调函数,获取上传文件信息 * realName真实文件名 * saveName文件保存名 * maxSize文件实际大小 */function callback(realName,saveName,maxSize){$("#photo_").val(saveName);//回调后其它操作}</script><tr><td>头像：</td><td><input type="hidden" name="photo" id="photo_"></input><input type="button" onclick="openUpload_()" value="上传"/></td></tr>

文件上传的JSP代码，需要注意的是在head标签内添加<base target="_self">

以防止页面跳转时弹出新窗口，用户选择指定文件，点击上传时就提交表单访问指定后台代码

<%@ include file="/WEB-INF/jsp/header.jsp" %><%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><meta http-equiv="pragma" content="no-cache" /><base target="_self"><title>文件上传</title></head><body><h5>文件上传</h5><hr/><form id="file_upload_id" name="file_upload_name" action="<%=root%>/CommonController.jhtml?method=doFileUpload" method="post" enctype="multipart/form-data"><input type="hidden" name="functionId" value="${functionId}"/><input type="hidden" name="fileType" value="${fileType}"/><input type="hidden" name="maxSize" value="${maxSize}"/><div><input type="file" name="file_upload"/></div><c:if test="${maxSize!=null}"><div style="font: 12">文件最大不能超过${maxSize}MB</div></c:if><c:if test="${fileType!=null}"><div style="font: 12">文件格式必须是：${fileType}</div></c:if><div><input type="submit" value="上传"/></div></form></body></html>

CommonController目前有两个方法，一个是跳转到上传页面的方法，一个是执行上传操作的方法doFileUpload，上传方法运行的大概逻辑是：首先获取页面的请求参数，fileType用于限制上传文件格式，

maxSize用于限制上传文件最大值，随后创建上传目录上传即可。

public class CommonController extends BaseController {Log log = LogFactory.getLog(CommonController.class);Properties fileUploadPro = null;public CommonController(){fileUploadPro = PropertiesUtil.getPropertiesByClass("fileupload.properties");}@Overridepublic ModeAndView init(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {return null;}/** * 跳转到文件上传页 * @param request * @param response * @return * @throws ServletException * @throws IOException */public ModeAndView goFileUpload(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {String functionId = request.getParameter("functionId");String fileType = request.getParameter("fileType");String maxSize = request.getParameter("maxSize");ModeAndView mav = new ModeAndView("/WEB-INF/jsp/common/fileUpload.jsp");if(functionId!=null && !"".equals(functionId.trim())){mav.addObject("functionId", functionId);}if(fileType!=null && !"".equals(fileType.trim())){mav.addObject("fileType", fileType);}if(maxSize!=null && !"".equals(maxSize.trim())){mav.addObject("maxSize", maxSize);}return mav;}/** * 上传文件 * @param request * @param response * @return * @throws ServletException * @throws IOException */@SuppressWarnings("unchecked")public ModeAndView doFileUpload(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {//获取并解析文件类型和支持最大值String functionId = request.getParameter("functionId");String fileType = request.getParameter("fileType");String maxSize = request.getParameter("maxSize");//临时目录名String tempPath = fileUploadPro.getProperty("tempPath");//真实目录名String filePath = fileUploadPro.getProperty("filePath");FileUtil.createFolder(tempPath);FileUtil.createFolder(filePath);DiskFileItemFactory factory = new DiskFileItemFactory();//最大缓存factory.setSizeThreshold(5*1024);//设置临时文件目录factory.setRepository(new File(tempPath));ServletFileUpload upload = new ServletFileUpload(factory);if(maxSize!=null && !"".equals(maxSize.trim())){//文件最大上限upload.setSizeMax(Integer.valueOf(maxSize)*1024*1024);}try {//获取所有文件列表List<FileItem> items = upload.parseRequest(request);for (FileItem item : items) {if(!item.isFormField()){//文件名String fileName = item.getName();//检查文件后缀格式String fileEnd = fileName.substring(fileName.lastIndexOf(".")+1).toLowerCase();if(fileType!=null && !"".equals(fileType.trim())){boolean isRealType = false;String[] arrType = fileType.split(",");for (String str : arrType) {if(fileEnd.equals(str.toLowerCase())){isRealType = true;break;}}if(!isRealType){//提示错误信息:文件格式不正确super.printJsMsgBack(response, "文件格式不正确!");return null;}}//创建文件唯一名称String uuid = UUID.randomUUID().toString();//真实上传路径StringBuffer sbRealPath = new StringBuffer();sbRealPath.append(filePath).append(uuid).append(".").append(fileEnd);//写入文件File file = new File(sbRealPath.toString());item.write(file);//上传成功，向父窗体返回数据:真实文件名,虚拟文件名,文件大小StringBuffer sb = new StringBuffer();sb.append("window.returnValue='").append(fileName).append(",").append(uuid).append(".").append(fileEnd).append(",").append(file.length()).append("';");sb.append("window.close();");super.printJsMsg(response, sb.toString());log.info("上传文件成功,JS信息："+sb.toString());}//end of if}//end of for}catch (Exception e) {//提示错误:比如文件大小super.printJsMsgBack(response, "上传失败,文件大小不能超过"+maxSize+"M!");log.error("上传文件异常!",e);return null;}return null;}}

至此一个文件上传即已实现，而且能够基本满足不同模块的上传通用性，我还留着个functionId参数用于以后针对不同模块上传文件到不同目录。

转载至：http://blessht.iteye.com/blog/1405057

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