Spring Boot-将文件上传到服务器

Question

The code belows prompts a user to select a file on his local repository, enter some input fields and then upload the file to a server. Currently, it will store it in a /tmp folder, as it is created by createTempFile. The file is successfully created, and an object is created with a reference to that file as needed by the business case. Yay!

However, I want to store all files in a seperate and organizable folder like "/uploadedFiles" on the server repository.

1. I have tried several things, from creating an empty file on the repository folder and then attempting an overwrite on to it, to just copying the uploaded file to the folder. None of what seemed to be easy fixes worked so far, unless I missed something obvious (which I probably did).

2. The files created all have a long sequence of numbers after the file extension in their names, like "testfile.xls1612634232432"; is this from the buffer of the inputstream?

The code below is how it currently works, with just writing the uploaded file to a temp file in the /tmp directory. I need to get it to any other directory of my choosing, and then eligibly pass it to the object constructor.

The method begins at newTestUpload.

@MultipartConfig
@RestController
@RequestMapping(value = "/Teacher", produces = "text/html;charset=UTF-8")
public class Teacher {
    TestController testcont = TestController.getInstance();

    @GetMapping("")
    @ResponseBody

    public String homePage(@RequestParam(value = "file", required = false) String name, HttpServletRequest request,
            HttpServletResponse response) {

        StringBuilder sb = new StringBuilder();

        sb.append("<p> <a href='/Teacher/NewTest'>New Test upload</a></p>\n"
                + "<p><a href='/SelectTest'>Select Test File</a> <button type='button'>Send Test</button></p>"
                + "\n \n \n" + "<p><a>Current Test for students:</a>\n <a href='/getCurrentTest'></a></p>");

        return sb.toString();
    }

    @PostMapping
    @RequestMapping("/NewTest")
    @ResponseBody

    public String newTestUpload(HttpServletRequest request, HttpServletResponse response) {
        StringBuilder sb = new StringBuilder();
        try {

            if (!request.getParameterNames().hasMoreElements()) {
                sb.append("<p><form action='' method='post' enctype='multipart/form-data'>"
                        + "<label>Enter file</label><input type='file' name='file'>"

                        + "<button type='submit'>Upload</button></p>"

                        + "<p><form action='/testName'>Test Name: <input type='text' name='name' value=''></p>"

                        + "<p><form action='/addInfo'>Comment: <input type='text' comment='comment' value=''></p>"

                        + "<p>Answer 1: <input type='text' Answer='answer1' value=''></p>"

                        + "<p>Answer 2: <input type='text' Answer='answer2' value=''></p>"

                        + "</form>"

                        + "<a href='/Teacher'>Back</a>\n");
                return sb.toString();
            } else if (request.getParameter("name") != "" && request.getParameter("comment") != ""
                    && request.getParameter("answer1") != "" && request.getParameter("answer2") != "") {

                try {
                    // This is where the magic happens

                    Part filePart = request.getPart("file");
                    String fileName = Paths.get(filePart.getSubmittedFileName()).getFileName().toString();

                    InputStream fileContent = filePart.getInputStream();

                    byte[] buffer = new byte[fileContent.available()];
                    fileContent.read(buffer);

                    File testExcel = File.createTempFile(fileName, "", null);

                    OutputStream outStream = new FileOutputStream(testExcel);
                    outStream.write(buffer);

                    // double ans1 =
                    // Double.parseDouble(request.getParameter("answer1"));
                    // double ans2 =
                    // Double.parseDouble(request.getParameter("answer2"));


                    Test test = new Test(testExcel, request.getParameter("name"), request.getParameter("comment"),
                            request.getParameter("answer1"), request.getParameter("answer2"));

                    testcont.addTest(test);

                    testExcel.deleteOnExit();
                    outStream.close();

                    sb.append("New test uploaded!<br/>\n<a href='/Teacher'>Back</a>\n" + testExcel.getPath()
                            + "<p>_________</p>" + test.getFile().getPath());
                    return sb.toString();

                } catch (Exception e) {
                    sb.append("<h1>Couldnt insert test</h1>\n" + e.getMessage() + e.getStackTrace() + e.getCause());
                    response.setStatus(HttpServletResponse.SC_OK);
                    e.printStackTrace();
                    return sb.toString();
                }

            } else {
                sb.append("failed<br/>\n<a href='/Teacher/NewTest'>Back</a>\n");
                response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
                return sb.toString();
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";

    }

}

Answer 1

Instead of creating a temp file, create file in the directory that you want to create.

OutputStream outStream = new FileOutputStream(new File("<fileName>"));

If you want to create file first without data. you can use below code, it will create directory as well if not already created:

    public static void saveToFile(String folderPath, String fileName) throws IOException {
        File directory = new File(folderPath);
        if (!directory.exists() && !directory.mkdirs()) {
            throw new IOException("Directory does not exist and could not be created");
        }
        String filePath = folderPath + File.separator + fileName;
        File theFile = new File(filePath);
        if (!theFile.exists()) {
            try {
                theFile.createNewFile();
            } catch (IOException e) {
                throw new IOException("Facing issues in creating file " + filePath, e);
            }
        }
    }

Answer 2

File testExcel = File.createTempFile(fileName, "", null);

replaced with:

File testExcel = new File("/tests/", fileName);
testExcel.getParentFile().mkdirs();

did the trick! Works like a charm now.