Glassfish 似乎在我也想保存图像文件的路径中添加了额外的内容，是否有某种方法可以仅使用我的 servlet 获得的绝对路径

String appPath = request.getServletContext().getRealPath("");?

我花了几天时间尝试不同的方法来上传图像文件并让 servlet 将其保存到磁盘。

我用了这个例子：http://www.codejava.net/java-ee/servlet/how-to-write-upload-file-servlet-with-servlet-30-api http://www.codejava.net/java-ee/servlet/how-to-write-upload-file-servlet-with-servlet-30-api

使用调试我可以看到文件名和路径信息已正确收集，但代码在“part.write(savePath + File.separator + fileName);”处失败

glassfish的异常报告是：

exception

java.io.FileNotFoundException: C:\Program Files\glassfish-3.1.2.2\glassfish\domains\domain1\generated\jsp\com.onemore_onemore-web_war_1.0-SNAPSHOT\D:\Dropbox\Git\Brian_JEE\onemore\onemore\onemore-web\target\onemore-web-1.0-SNAPSHOT\image\screengrab_all_products.jpg (The filename, directory name, or volume label syntax is incorrect)

我可以看到正确的路径作为此异常的一部分D:\Dropbox\Git\Brian_JEE\onemore\onemore\onemore-web\target\onemore-web-1.0-SNAPSHOT\image\screengrab_all_products.jpg

JSP

<form action="${pageContext.request.contextPath}/imageupload" method="post" enctype="multipart/form-data" name="productForm" id="productForm">
<input type="file" name="file" id="file">
<input type="submit" name="Submit" value="Submit"></td>
</form>

Servlet

@WebServlet(name = "UploadImageServlet", urlPatterns = {"/imageupload"})
@MultipartConfig(fileSizeThreshold = 1024 * 1024 * 2, // 2MB 
maxFileSize = 1024 * 1024 * 10, // 10MB
maxRequestSize = 1024 * 1024 * 50)   // 50MB
public class UploadImageServlet extends HttpServlet {

    /**
     * Name of the directory where uploaded files will be saved, relative to the
     * web application directory.
     */
    private static final String SAVE_DIR = "image";

    /**
     * handles file upload
     */
    @Override
    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
      // gets absolute path of the web application
        String appPath = request.getServletContext().getRealPath("");
        // constructs path of the directory to save uploaded file
        String savePath = appPath + File.separator + SAVE_DIR;

        // creates the save directory if it does not exists
        File fileSaveDir = new File(savePath);
        if (!fileSaveDir.exists()) {
            fileSaveDir.mkdir();
        }

        for (Part part : request.getParts()) {
            String fileName = extractFileName(part);
            part.write(savePath + File.separator + fileName);
        }

        request.setAttribute("message", "Upload has been done successfully!");
        getServletContext().getRequestDispatcher("/WEB-INF/jsp/newproduct.jsp").forward(
                request, response);
    }

    /**
     * Extracts file name from HTTP header content-disposition
     */
    private String extractFileName(Part part) {
        String contentDisp = part.getHeader("content-disposition");
        String[] items = contentDisp.split(";");
        for (String s : items) {
            if (s.trim().startsWith("filename")) {
                return s.substring(s.indexOf("=") + 2, s.length() - 1);
            }
        }
        return "";
    }
}

切勿使用 getRealPath()

您不应将上传的文件保存在部署文件夹中。我之前已经解释过很多次了。这些解释之一可以在这个答案中找到：上传的图片仅在刷新页面后可用 https://stackoverflow.com/questions/8885201/uploaded-image-only-available-after-refreshing-the-page/8889096#8889096.

在某些博客/文章中找到的任何使用过的 JSP/Servlet 代码片段getRealPath()方法应与一大袋盐一起服用。它的质量和作者的知识应该受到强烈质疑。也就是说，该方法在现实世界中没有合理的用例 https://stackoverflow.com/questions/12160639/what-does-mean-in-the-function-servletcontext-getrealpath/12160863#12160863.

将上传的文件保存在部署文件夹之外的固定路径中。也可以看看如何使用 Commons FileUpload 设置存储文件上传的文件夹 https://stackoverflow.com/questions/13528081/how-do-i-set-the-folder-for-storing-file-uploads-using-commons-fileupload/13532453#13532453.