Dropwizard文件上传

Question

我必须从我的网站上传一个文件，但cnt似乎可以使用drop wizard。

这是我网站上的表格。

   <form enctype="multipart/form-data" method="POST" action="UploadFile">
     <input type="file" id="fileUpload" name="file"/>
     <input type="hidden" id="fileName" name="fileName"/>
     <input type="submit" value="Upload"/>
   </form>

如何在后端接收文件？

解决办法是

    @POST
    @Consumes(MediaType.MULTIPART_FORM_DATA)
    public Response uploadFile(
        @FormDataParam("file") final InputStream fileInputStream,
        @FormDataParam("file") final FormDataContentDisposition contentDispositionHeader) {


    String filePath = uploadLocation + newFileName;
    saveFile(fileInputStream, filePath);
    String output = "File can be downloaded from the following location : " + filePath;

    return Response.status(200).entity(output).build();

}

private void saveFile(InputStream uploadedInputStream,
        String serverLocation) {
    try {
            OutputStream outputStream = new FileOutputStream(new      File(serverLocation));
            int read = 0;
            byte[] bytes = new byte[1024];

            outputStream = new FileOutputStream(new File(serverLocation));
            while ((read = uploadedInputStream.read(bytes)) != -1) {
                outputStream.write(bytes, 0, read);
            }
            outputStream.flush();
            outputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }   

Answer 1

确保将dropwizard表单依赖项添加到pom.xml

<dependency>
    <groupId>io.dropwizard</groupId>
    <artifactId>dropwizard-forms</artifactId>
    <version>${dropwizard.version}</version>
    <type>pom</type>
</dependency>

您的资源似乎不错，无论如何，我已经上传了一个示例项目，用于使用Dropwizard上传文件 - https://github.com/juanpabloprado/dw-multipart

@POST
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response uploadFile(
        @FormDataParam("file") InputStream uploadedInputStream,
        @FormDataParam("file") FormDataContentDisposition fileDetail) throws MessagingException, IOException {

    String uploadedFileLocation = "C:/Users/Juan/Pictures/uploads/" + fileDetail.getFileName();

    // save it
    writeToFile(uploadedInputStream, uploadedFileLocation);
    String output = "File uploaded to : " + uploadedFileLocation;
    return Response.ok(output).build();
}

// save uploaded file to new location
private void writeToFile(InputStream uploadedInputStream, String uploadedFileLocation) throws IOException {
    int read;
    final int BUFFER_LENGTH = 1024;
    final byte[] buffer = new byte[BUFFER_LENGTH];
    OutputStream out = new FileOutputStream(new File(uploadedFileLocation));
    while ((read = uploadedInputStream.read(buffer)) != -1) {
        out.write(buffer, 0, read);
    }
    out.flush();
    out.close();
}

Answer 2

使用Dropwizard 0.9.2，您必须添加依赖项：

<dependency>
    <groupId>io.dropwizard</groupId>
    <artifactId>dropwizard-forms</artifactId>
    <version>${dropwizard.version}</version>
    <type>pom</type>
</dependency>

以及注册多部分功能：

    environment.jersey().register(MultiPartFeature.class);

Answer 3

您可以使用 nio 在较少的行数中保存到服务器

java.nio.file.Path outputPath = FileSystems.getDefault().getPath(<upload-folder-on-server>, fileName);
Files.copy(fileInputStream, outputPath);

此外，如果您使用的是0.7.0-rc2，那么您的pom.xml中将需要这种依赖性

<dependency>
<groupId>com.sun.jersey.contribs</groupId>
<artifactId>jersey-multipart</artifactId>
<version>1.18</version>
</dependency>