java - 尝试在 java 中上传图像时出现 NoSuchFileException

Question

当我尝试使用 post 方法通过表单上传文件时，会发生 NoSuchFileException 类型的错误，但我不知道为什么。

这是代码:

if (req.getPart("file") != null) {
            Part file = req.getPart("file");
            String fileName = file.getSubmittedFileName();
            DiskFileItemFactory factory = new DiskFileItemFactory();
            File repository = new File("./uploads");
            factory.setRepository(repository);
            try {
                File thisFile = new File(repository, fileName);
                try (InputStream input = file.getInputStream()) {
                    Files.copy(input, thisFile.toPath());
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            UserDao.getInstance().addPicture("./uploads" + fileName, oldUser);
            UserDao.getInstance().update(user, oldUser);
        }

我确信出了什么问题，但我看不到它......有人可以帮助我吗？

一开始我有这个代码，但试图解决错误我改变了它:

 Part file = req.getPart("file");
    String filename = file.getSubmittedFileName();
    DiskFileItemFactory factory = new DiskFileItemFactory();
    File repository = new File("./uploads");
    factory.setRepository(repository);
    ServletFileUpload upload = new ServletFileUpload(factory);
    try {
        List<FileItem> items = upload.parseRequest(req);

        File thisFile = new File(repository, filename);

        try (InputStream input = file.getInputStream()) {
            Files.copy(input, thisFile.toPath());
        }
    } catch (FileUploadException e) {
        e.printStackTrace();
    }

这是堆栈跟踪:

java.nio.file.NoSuchFileException: ./uploads/photo.jpeg
java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:92)
java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111)
java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:116)
java.base/sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:219)
java.base/java.nio.file.spi.FileSystemProvider.newOutputStream(FileSystemProvider.java:478)
java.base/java.nio.file.Files.newOutputStream(Files.java:223)
java.base/java.nio.file.Files.copy(Files.java:3143)
com.marcosvalens.controller.UserFormController.doPost(UserFormController.java:82)
javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
com.marcosvalens.interceptor.RequestLoginFilter.doFilter(RequestLoginFilter.java:39)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)

Answer 1

您创建了一个DiskFileItemFactory，然后，显然，您祈祷它能做一些事情。这不是您使用此 API 的方式；您必须将 factory 变量传递给构造函数:new ServletFileUpload(factory)。您的代码片段不包含此内容；想必它会比您粘贴的内容更高。