HTML代码:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <link href="../css/bootstrap.min.css" rel="stylesheet"> </head> <body> <input type="file" id="file" name="file"/><br> <button id="uploadBtn" class="btn btn-primary" type="button" >上传</button><br> <img src="../img/9.jpg" class="img-circle" style="height: 255px; 255px"> </body> <script src="../js/jquery-1.7.1.min.js"></script> <!--想要使用ajaxFileUpload插件必须引入这个js--> <script src="../js/ajaxfileupload.js"></script> <script> $(()=>{ $('#uploadBtn').click(function () { $.ajaxFileUpload({ url:'../uploadFile', type:'post', fileElementId: "file", //需要上传的文件域的ID，即<input type="file">的ID dataType:'String', success: function(result) { alert(result); $(".img-circle").attr("src","../upload/" + result); } }) }) }) </script> </html>
后台servlet代码:
@WebServlet(name = "UploadFileServlet",value = "/uploadFile") //必须加此注解 重要! @MultipartConfig public class UploadFileServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Part part = request.getPart("file"); String header = part.getHeader("content-disposition"); //获得上传文件名 String path = header.substring(header.indexOf("filename=") + 10, header.length() - 1); // 获取文件的真实路径 String realPath = this.getServletContext().getRealPath("/upload"); String newFileName = generateUploadFileName(getRealName(path)); File file = new File(realPath); //文件夹不存在则创建 if (!file.exists()) { file.mkdirs(); } // 获取输入流 InputStream inputStream = part.getInputStream(); // 定义输出流 FileOutputStream outputStream = new FileOutputStream(new File(file, newFileName)); // 从输入流中读入数据并写到输出字节流中 int len = -1; byte[] bytes = new byte[1024]; while ((len = inputStream.read(bytes)) != -1) { outputStream.write(bytes, 0, len); } // 关闭资源 outputStream.close(); inputStream.close(); // 删除临时文件 part.delete(); //向服务器返回新文件名 response.getWriter().print(newFileName); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public static String getRealName(String path) { int index = path.lastIndexOf("\"); if (index == -1) { index = path.lastIndexOf("/"); } return path.substring(index + 1); } //传入旧文件名，获得新的文件名 public static String generateUploadFileName(String name){ String suffixName = name.substring(name.lastIndexOf(".")); return System.currentTimeMillis() + "_" +(int)(Math.random() * 100000) +suffixName; } }