文件上载与Restlet中的描述

时间:2015-02-03 06:14:44

标签: java file-upload restlet

我需要使用 restlet 上传文件以及其他一些数据。所以我创建了一个示例html页面,如下所示。

<html>
<body>
    <h1>*****Upload File with RESTFul WebService*****</h1>
    <form action="http://localhost:8080/test/api/streams/sample.json" method="post" enctype="multipart/form-data">


        <fieldset>
            <legend>Upload File</legend>

            <input type="file" name="fileToUpload"/><br />  
            <br /><br />
            Party ID<input type="text" name="mybody"  /><br />


            <input type="submit" name="Upload" id="Upload" value="Upload" />
        </fieldset>
    </form>
</body>

我需要读取输入字段中的值以及文件数据。现在可以读取文件内容。我可以在同一个api调用中从该输入框中获取值。

@Post
public Representation accept(Representation entity) throws Exception {
Representation result = null;


if (entity != null) {
  if (MediaType.MULTIPART_FORM_DATA.equals(entity.getMediaType(), true)) {
    // 1/ Create a factory for disk-based file items
    DiskFileItemFactory factory = new DiskFileItemFactory();
    factory.setSizeThreshold(1000240);

    // 2/ Create a new file upload handler based on the Restlet
    // FileUpload extension that will parse Restlet requests and
    // generates FileItems.
    RestletFileUpload upload = new RestletFileUpload(factory);

    // 3/ Request is parsed by the handler which generates a
    // list of FileItems
    FileItemIterator fileIterator = upload.getItemIterator(entity);

    // Process only the uploaded item called "fileToUpload"
    // and return back
    boolean found = false;
    while (fileIterator.hasNext() && !found) {
      FileItemStream fi = fileIterator.next();
      Extractor extractor = new Extractor(getContext());

      if (fi.getFieldName().equals("fileToUpload")) {
        found = true;
        // consume the stream immediately, otherwise the stream
        // will be closed.
        StringBuilder sb = new StringBuilder("media type: ");
        sb.append(fi.getContentType()).append("\n");
        sb.append("file name : ");
        sb.append(fi.getName()).append("\n");
        BufferedReader br = new BufferedReader(new InputStreamReader(fi.openStream()));
        String line = null;
        while ((line = br.readLine()) != null) {
          sb.append(line);
        }
        sb.append("\n");
        result = new StringRepresentation(sb.toString(), MediaType.TEXT_PLAIN);
      }
    }
  } else {
    setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
  }
  System.out.println("result==" + result);
}


return result;

}

1 个答案:

答案 0 :(得分:1)

首先,您需要了解请求的内容。如果您查看已发送的请求(firebug或其他内容),您将看到以下内容:

-----------------------------2003194375274723921294130757
Content-Disposition: form-data; name="fileToUpload";
filename="mysql.sql" Content-Type: application/sql 

<<YOUR FILE CONTENT>>
-----------------------------2003194375274723921294130757
Content-Disposition: form-data; name="mybody"

my value
-----------------------------2003194375274723921294130757
Content-Disposition: form-data; name="Upload"

Upload
-----------------------------2003194375274723921294130757--

正如您所看到的,您的请求中有几个部分。这意味着您可以在服务器资源中迭代这些部分。在您提供的代码中,您只查找名称为fileToUpload的条目,如果找到,则会中断循环。

您可以更新代码以执行完整循环,并检查输入字段的值mybody,如下所述:

while (fileIterator.hasNext()) {
    FileItemStream fi = fileIterator.next();

    if ("mybody".equals(fi.getFieldName())) {
        BufferedReader br = new BufferedReader(
                 new InputStreamReader(fi.openStream()));
        String fieldValue = null;
        if ((line = br.readLine()) != null) {
            fieldValue = line;
        }
    } else if ("fileToUpload".equals(fi.getFieldName())) {
        (...)
    }
    (...)
}

希望它有所帮助, 亨利