1. 进行文件上传时, 表单需要做的准备:
1). 请求方式为 POST: <form action="uploadServlet" method="post" ... > 2). 使用 file 的表单域: <input type="file" name="file"/> 3). 使用 multipart/form-data 的请求编码方式: <form action="uploadServlet" method="post" enctype="multipart/form-data">
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=UTF-8"> <title>Insert title here</title> </head> <body> <form action="${pageContext.request.contextPath }/uploadServlet" method="post" enctype="multipart/form-data"> File:<input type="file" name="file" /> <br> desc:<input type="text" name="desc"> <br> <input type="submit"> </form> </body> </html> 4). 关于 enctype: > application/x-www-form-urlencoded：表单 enctype 属性的默认值。这种编码方案使用有限的字符集，当使用了非字母和数字时， 必须用”%HH”代替(H 代表十六进制数字)。对于大容量的二进制数据或包含非 ASCII 字符的文本来说，这种编码不能满足要求。 > multipart/form-data：form 设定了enctype=“multipart/form-data”属性后，表示表单以二进制传输数据
2.使用commons-fileupload组件上传文件
lib：
commons-fileupload-1.2.1.jar commons-io-2.0.jar
基本思想:
> commons-fileupload 可以解析请求, 得到一个 FileItem 对象组成的 List > commons-fileupload 把所有的请求信息都解析为 FileItem 对象, 无论是一个一般的文本域还是一个文件域. > 可以调用 FileItem 的 isFormField() 方法来判断是一个 表单域 或不是表单域(则是一个文件域) > 再来进一步获取信息
public class uploadServlet extends HttpServlet { private static final long serialVersionUID = -7199179697800254436L; @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { this.doPost(req, resp); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { //1、创建一个DiskFileItemFactory工厂 DiskFileItemFactory factory = new DiskFileItemFactory(); FileCleaningTracker fileCleaningTracker = FileCleanerCleanup.getFileCleaningTracker(getServletContext()); factory.setFileCleaningTracker(fileCleaningTracker); // 设置内存缓冲区，超过后写入临时文件 factory.setSizeThreshold(1024 * 1024 * 5); File tmpDirectory = new File("d:\\tempDirectory"); factory.setRepository(tmpDirectory); //2、创建一个文件上传解析器 ServletFileUpload upload = new ServletFileUpload(factory); //设置上传的单个文件最大字节数 upload.setSizeMax(1024 * 1024 * 5); try { List<FileItem> parseRequest = upload.parseRequest(req); for (FileItem fileItem : parseRequest) { // 2.遍历items：若是一般表单域，打印信息 if (fileItem.isFormField()) { String name = fileItem.getFieldName(); String value = fileItem.getString(); System.out.println(name + ":" + value); }else{ //若是文件域则把文件保存到 d:\\files 目录下. String fieldName = fileItem.getFieldName(); String name = fileItem.getName(); String contentType = fileItem.getContentType(); long size = fileItem.getSize(); System.out.println(fieldName); System.out.println(name); System.out.println(contentType); System.out.println(size); InputStream inputStream = fileItem.getInputStream(); byte[] buffer = new byte[1024]; int len = 0; fieldName ="d:\\files\\"+name; System.out.println(fieldName); FileOutputStream outputStream = new FileOutputStream(fieldName); while((len=inputStream.read(buffer))!=-1){ outputStream.write(buffer, 0, len); } outputStream.close(); inputStream.close(); } } } catch (FileUploadException e) { // TODO Auto-generated catch block e.printStackTrace(); } // ServletInputStream inputStream = req.getInputStream(); // Reader reader = new InputStreamReader(inputStream); // BufferedReader bufferedReader = new BufferedReader(reader); // String str = null; // while ((str = bufferedReader.readLine()) != null) { // System.out.println(str); // } } } 多文件上传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=UTF-8"> <title>Insert title here</title> <script type="text/javascript" src="${pageContext.request.contextPath }/scripts/jquery-1.7.2.js"></script> <script type="text/javascript"> $(function(){ var i = 2; $("#addFile").click(function(){ $(this).parent().parent().before("<tr class='file'><td>File" + i + ":</td><td><input type='file' name='file" + i + "'/></td></tr>" + "<tr class='desc'><td>Desc" + i + ":</td><td><input type='text' name='desc" + i + "'/><button id='delete" + i + "'>删除</button></td></tr>"); i++; //获取新添加的删除按钮 $("#delete" + (i-1)).click(function(){ var $tr = $(this).parent().parent(); $tr.prev("tr").remove(); $tr.remove(); //对 i 重写排序 $(".file").each(function(index){ var n = index + 1; $(this).find("td:first").text("File" + n); $(this).find("td:last input").attr("name", "file" + n); }); $(".desc").each(function(index){ var n = index + 1; $(this).find("td:first").text("Desc" + n); $(this).find("td:last input").attr("name", "desc" + n); }); i = i - 1; }); return false; }); }); </script> </head> <body> <font color="red">${msg }</font> <br><br> <form action="${pageContext.request.contextPath }/app/FileUploadServlet" method="post" enctype="multipart/form-data"> <table> <tr class="file"> <td>File1:</td> <td><input type="file" name="file1"/></td> </tr> <tr class="desc"> <td>Desc1:</td> <td><input type="text" name="desc1"/></td> </tr> <tr> <td><input type="submit" id="submit" value="提交"/></td> <td><button id="addFile">新增一个附件</button></td> </tr> </table> </form> </body> </html>upload.properties
exts=pptx,docx,doc,zip file.MaxSize=102400 total.file.max.size=512000 FileUploadAppProperties public class FileUploadAppProperties { private Map<String, String> properties = new HashMap<>(); private FileUploadAppProperties() { } private static FileUploadAppProperties instance = new FileUploadAppProperties(); public static FileUploadAppProperties getInstance() { return instance; } public void addProperties(String propertyName, String propertyValue) { properties.put(propertyName, propertyValue); } public String getProperties(String propertyName) { return properties.get(propertyName); } }
监听器加载配置文件
FileUploadAppLitener
@WebListener public class FileUploadAppLitener implements ServletContextListener { @Override public void contextInitialized(ServletContextEvent arg0) { InputStream in = getClass().getClassLoader().getResourceAsStream("/upload.properties"); Properties properties = new Properties(); try { properties.load(in); for (Map.Entry<Object, Object> pro : properties.entrySet()) { String propertName = (String) pro.getKey(); String propertValue = (String) pro.getValue(); FileUploadAppProperties.getInstance().addProperties(propertName, propertValue); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } @Override public void contextDestroyed(ServletContextEvent arg0) { // TODO Auto-generated method stub } }FileUploadBean public class FileUploadBean { private Integer id; // 文件名 private String fileName; // 文件路径 private String filePath; // 文件描述 private String fileDesc; public FileUploadBean() { } public FileUploadBean(String fileName, String filePath, String fileDesc) { super(); this.fileName = fileName; this.filePath = filePath; this.fileDesc = fileDesc; } setter ...getter .. } FileUploadServlet @WebServlet("/app/FileUploadServlet") public class FileUploadServlet extends HttpServlet { private static final long serialVersionUID = 1L; private static final String FILE_PATH = "/WEB-INF/files"; private static final String TEMP_DIR = "d:\\tempDirectory"; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String path; try { ServletFileUpload upload = getServletUpload(); String fileSaveDir = getServletContext().getRealPath(FILE_PATH); File file = new File(fileSaveDir); if (!file.exists()) { file.mkdirs(); } // 把需要上传的FileItem 都放入到该Map中 // 键：文件的待存放的路径，值：对应的FileItem对象 Map<String, FileItem> uploadFiles = new HashMap<>(); // 解析请求，得到FileItem 的集合 List<FileItem> items = upload.parseRequest(request); // 1.构建FileUploadBean 的集合,同时填充uploadFiles List<FileUploadBean> beans = buildFileUploads(items, uploadFiles); // 2.校验扩展名 vaidateExtName(beans); // 3.校验文件的大小：在解析时，已经检验了，我们只需通过异常得到结果 // 4.进行文件的上传操作 upload(uploadFiles); // 5.把上传的信息保存到数据库 saveBean(beans); //6. 删除临时文件夹的临时文件 FileUtils.delAllFile(TEMP_DIR); path = "/app/success.jsp"; } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); String msg = e.getMessage(); path = "/app/upload.jsp"; request.setAttribute("msg", msg); } request.getRequestDispatcher(path).forward(request, response); } private void saveBean(List<FileUploadBean> beans) { // TODO Auto-generated method stub } private void upload(Map<String, FileItem> uploadFiles) throws IOException { for (Map.Entry<String, FileItem> uploadFile : uploadFiles.entrySet()) { String filePath = uploadFile.getKey(); FileItem fileItem = uploadFile.getValue(); System.out.println(filePath); upload(filePath, fileItem.getInputStream()); } } private void upload(String filePath, InputStream in) throws IOException { FileOutputStream outputStream = new FileOutputStream(filePath); byte[] buffer = new byte[1024]; int len = 0; while ((len = in.read(buffer)) != -1) { outputStream.write(buffer, 0, len); } outputStream.close(); in.close(); } /** * 校验扩展名是否合法 * * @param beans */ private void vaidateExtName(List<FileUploadBean> beans) { String exts = FileUploadAppProperties.getInstance().getProperties("exts"); List<String> extList = Arrays.asList(exts.split(",")); for (FileUploadBean bean : beans) { String fileName = bean.getFileName(); String extName = fileName.substring(fileName.lastIndexOf(".") + 1); if (!extList.contains(extName)) { throw new InvalidExtNameException(fileName + "文件的扩展名不合法"); } } } private List<FileUploadBean> buildFileUploads(List<FileItem> items, Map<String, FileItem> uploadFiles) throws UnsupportedEncodingException { List<FileUploadBean> beans = new ArrayList<>(); // 1.遍历FileItem的集合，先得到的desc的Map<String,String>,其中键：fileName(desc1,desc2...) // 值表单域对应字段的值 Map<String, String> descs = new HashMap<>(); for (FileItem item : items) { if (item.isFormField()) { descs.put(item.getFieldName(), item.getString()); } } // 2/再遍历FileItem集合，得到文件域的FileItem对象 // 每个得到一个FileItem对象都创建一个FileUploadBean 对象 // 得到 fileName,构建filePath,从1的Map中得到当前FileItem对应的那个desc // 使用fileName后面的数字匹配 for (FileItem item : items) { if (!item.isFormField()) { String fieldName = item.getFieldName(); String index = fieldName.substring(fieldName.length() - 1); // 上传文件名 String fileName = item.getName(); System.out.println(fileName); String desc = descs.get("desc" + index); String filePath = getFilePath(fileName); FileUploadBean fileUploadBean = new FileUploadBean(fileName, filePath, desc); beans.add(fileUploadBean); uploadFiles.put(filePath, item); } } return beans; } private String getFilePath(String fileName) { String extName = fileName.substring(fileName.lastIndexOf(".")); // 生成随机数，防止filePath相同 Random random = new Random(); int randomNumber = random.nextInt(10000); String filePath = getServletContext().getRealPath(FILE_PATH) + File.separator + System.currentTimeMillis() + randomNumber + extName; return filePath; } private ServletFileUpload getServletUpload() { String exts = FileUploadAppProperties.getInstance().getProperties("exts"); String maxSize = FileUploadAppProperties.getInstance().getProperties("file.MaxSize"); String total = FileUploadAppProperties.getInstance().getProperties("total.file.max.size"); System.out.println(exts); DiskFileItemFactory factory = new DiskFileItemFactory(); // 设置内存缓冲区，超过后写入临时文件 factory.setSizeThreshold(1024 * 5); File tmpDirectory = new File(TEMP_DIR); factory.setRepository(tmpDirectory); // Create a new file upload handler ServletFileUpload upload = new ServletFileUpload(factory); // 解决路径或者文件名为乱码的问题 upload.setHeaderEncoding("UTF-8"); // Set overall request size constraint upload.setSizeMax(Long.parseLong(total));//设置整个表单的上传文件最大字节数 upload.setFileSizeMax(Long.parseLong(maxSize));//设置上传的单个文件最大字节数 return upload; } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); } } public class FileUtils { /** * 删除文件夹 * @param folderPath: 文件夹完整绝对路径 */ public static void delFolder(String folderPath) { try { // 删除完里面所有内容 delAllFile(folderPath); String filePath = folderPath; filePath = filePath.toString(); java.io.File myFilePath = new java.io.File(filePath); // 删除空文件夹 myFilePath.delete(); } catch (Exception e) { e.printStackTrace(); } } /** * 删除指定文件夹下所有文件 * @param path: 文件夹完整绝对路径 * @return */ public static boolean delAllFile(String path) { boolean flag = false; File file = new File(path); if (!file.exists()) { return flag; } if (!file.isDirectory()) { return flag; } String[] tempList = file.list(); File temp = null; for (int i = 0; i < tempList.length; i++) { if (path.endsWith(File.separator)) { temp = new File(path + tempList[i]); } else { temp = new File(path + File.separator + tempList[i]); } if (temp.isFile()) { temp.delete(); } if (temp.isDirectory()) { // 先删除文件夹里面的文件 delAllFile(path + "/" + tempList[i]); // 再删除空文件夹 delFolder(path + "/" + tempList[i]); flag = true; } } return flag; } }
http://www.cnblogs.com/lj821022/p/5720605.html
