文件上传

最新推荐文章于 2022-09-08 20:06:52 发布

原创最新推荐文章于 2022-09-08 20:06:52 发布 · 1.0k 阅读

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文章标签：

#file #string #encoding #attributes #buffer #stream

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本文介绍了一个使用Struts框架进行文件上传的例子，详细展示了如何在页面上设置文件输入框及对应的action处理过程，包括获取文件名、指定上传路径、读取并保存文件等步骤。

在form里定义一个formfile的对象， protected FormFile file;
在页面里写： <tr>
        <th>
            <Myapp:label key="uploadForm.file"/>
        </th>
        <td>
            <html:file property="file" size="50" styleId="file" />
        </td>
    </tr>

action里：

public ActionForward save(ActionMapping mapping, ActionForm form,
                              HttpServletRequest request,
                              HttpServletResponse response)
    throws Exception {
        if (log.isDebugEnabled()) {
            log.debug("Entering 'save' method");
        }

        // Extract attributes and parameters we will need
        ActionMessages messages = new ActionMessages();
        DocumentForm documentForm = (DocumentForm) form;
        boolean isNew = ("".equals(documentForm.getDocumentid()) || documentForm.getDocumentid() == null);

        DocumentManager mgr = (DocumentManager) getBean("documentManager");



        String encoding = request.getCharacterEncoding();

        if ((encoding != null) && (encoding.equalsIgnoreCase("utf-8"))) {
            response.setContentType("text/html; charset=utf-8");
        }

        DocumentForm theForm = (DocumentForm) form;
        //retrieve the file representation
        FormFile file = theForm.getFile();

//retrieve the file name
String fileName = file.getFileName();

String location = null;

        // the directory to upload to
        String uploadDir =
            servlet.getServletContext().getRealPath("/resources") + "/"
            + request.getRemoteUser() + "/";

//write the file to the file specified
File dirPath = new File(uploadDir);

        if (!dirPath.exists()) {
            dirPath.mkdirs();
        }

//retrieve the file data
InputStream stream = file.getInputStream();

        //write the file to the file specified
        OutputStream bos = new FileOutputStream(uploadDir + fileName);
        int bytesRead = 0;
        byte[] buffer = new byte[8192];

        while ((bytesRead = stream.read(buffer, 0, 8192)) != -1) {
            bos.write(buffer, 0, bytesRead);
        }
        theForm.setPath(uploadDir);
        bos.close();

        location = dirPath.getAbsolutePath()
            + Constants.FILE_SEP + file.getFileName();
        System.out.println("location..................."+ location);
        //close the stream
        stream.close();

        //destroy the temporary file created
        file.destroy();


        Document document = (Document) convert(documentForm);
        mgr.saveDocument(document);
        // add success messages
        if (isNew) {
            messages.add(ActionMessages.GLOBAL_MESSAGE,
                         new ActionMessage("document.added"));

// save messages in session to survive a redirect
saveMessages(request.getSession(), messages);

            return mapping.findForward("search");
        } else {
            messages.add(ActionMessages.GLOBAL_MESSAGE,
                         new ActionMessage("document.updated"));
            saveMessages(request, messages);

            return mapping.findForward("edit");
        }
    }

其中上传时遇到一个问题：

javax.servlet.ServletException: BeanUtils.populate

查询后找到答案，在<html:form>是加上这一属性：

enctype="multipart/form-data"

还不知道为什么。

先总结这么多，暂时记一下，过几天来加多文档的上传。