上傳程式碼分為web端和後端,注意事項已標明

<!-- web端程式碼 -->
<!-- 注意 input必須有name屬性,名字無所謂。form中必須加上enctype這個屬性,且方法為post -->
<form action="檔案上傳路徑" method="post" enctype="multipart/form-data">
    <input type="file" name="upload">
</form>

//Java後端程式碼
//需要的jar包 commons-fileupload-1.2.2.jar,commons-io-2.0.1.jar
    //初始化工具
    DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();
    ServletFileUpload servletFileUpload = new ServletFileUpload(diskFileItemFactory);
    FileOutputStream fileOutputStream = null;
    InputStream inputStream = null;
    String imagePath = null;
        try {
            @SuppressWarnings("unchecked")
            //解析請求
            List fileItems = servletFileUpload.parseRequest(request);
            for (FileItem fileItem : fileItems) {
                if (fileItem.isFormField()) {
                    // 普通form表單域
                    String fieldName = fileItem.getFieldName();//得到表單中input的name
                    if("username".equals(fieldName)){
                        user.setUsername(fileItem.getString());
                    }else if("age".equals(fieldName)){
                        System.out.println("age" + fileItem.getString());
                            if(fileItem.getString() != null){
                                user.setAge(new Integer(fileItem.getString()));
                            }
                    }else if("gender".equals(fieldName)){
                        user.setGender(new Integer(fileItem.getString()));
                    }else if("mail".equals(fieldName)){
                        user.setMail(fileItem.getString());
                    }else if("tel".equals(fieldName)){
                        user.setTel(fileItem.getString());
                    }
                } else {
                    // 不是普通表單域,上傳的檔案
                    inputStream = fileItem.getInputStream();//獲取檔案輸入流
                    byte[] bytes = new byte[1024];//緩衝區
                    Date date = new Date();
                    imagePath = request.getServletContext().getRealPath("images") + "\\" + date.getTime() + ".jpg";
                    File file = new File(imagePath);
                    fileOutputStream = new FileOutputStream(file);
                    int flag2 = 0;
                    while ((flag2 = inputStream.read(bytes)) != -1) {
                        fileOutputStream.write(bytes);
                    }
                }
            }
            imagePath = imagePath.substring(imagePath.lastIndexOf("\\") + 1, imagePath.length());
            //設定檔案路徑
            user.setImage(imagePath);
            //更新使用者資訊
            int updateFlag = userService.update(user);
            //關閉輸入輸出流
            fileOutputStream.close();
            inputStream.close();

            } catch (org.apache.commons.fileupload.FileUploadException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }