Question

这里我上传文件，我想读取文件类型和文件扩展名，但是当我给文件在FileUtils.copyFile（this.uploadFile，fileToCreate）附近获得nullpointer异常时;任何人都可以解决这个问题...

public class ImportAction extends ActionSupport implements ServletRequestAware {

    private static final long serialVersionUID = 1L;
    private File uploadFile;
    private String uploadFileName;
    private String uploadContentType;
    private HttpServletRequest servletRequest;

    public File getUploadFile() {
        return uploadFile;
    }

    public void setUploadFile(File uploadFile) {
        this.uploadFile = uploadFile;
    }

    public String getUploadFileName() {
        return uploadFileName;
    }

    public void setUploadFileName(String uploadFileName) {
        this.uploadFileName = uploadFileName;
    }

    public String getUploadContentType() {
        return uploadContentType;
    }

    public void setUploadContentType(String uploadContentType) {
        this.uploadContentType = uploadContentType;
    }
    RegisterDAO dao = new RegisterDAO();

    /**
     *
     * @return
     * @throws
     * Exception
     */
    @SuppressWarnings("unchecked")
    @Override
    public String execute() throws Exception {
        try {
            String filePath = servletRequest.getSession().getServletContext().getRealPath("/");
            System.out.println("Server path:" + filePath);
            File fileToCreate = new File(filePath, this.uploadFileName);
            FileUtils.copyFile(this.uploadFile, fileToCreate);
        } catch (Exception e) {
            e.printStackTrace();
            addActionError(e.getMessage());
            return INPUT;
        }
        Model m = new Model();
        String result = m.fileimport(uploadFile, uploadFileName);
        if (result.equals(SUCCESS)) {
            return SUCCESS;
        } else {
            addActionError(getText(result));
            return "failure";
        }
    }

    @Override
    public void validate() {
        System.out.println("inside validate of LA");
    }

    @Override
    public void setServletRequest(HttpServletRequest hsr) {
        this.servletRequest = hsr; //To change body of generated methods, choose Tools | Templates.
    }
}

这是我的jsp页面

<s:form method="post" action="file" enctype="multipart/form-data">
            <s:file label="choose file" name="uploadFile"></s:file>
            <s:submit></s:submit>
        </s:form>

我打印我的文件路径就像这样 filepathD：\兰芝斯\ ranjithdemo3 \构建\网络\

Answer 1

这是在不到24小时内使用此代码的第三个问题......这是由在线arcticle拍摄的吗？你能在这报告吗？

BTW，主要问题是在使用Struts2上传文件时，通过fileUploadInterceptor，你必须尊重以下结构

private File   <filevarname>;
private String <filevarname>FileName;
private String <filevarname>ContentType;

所以如果您的<filevarname>是“uploadFile”，那么您应该

private File uploadFile;
private String uploadFileFileName;
private String uploadFileContentType;

如果您将其更改为“上传”，则应为

private File upload;
private String uploadFileName;
private String uploadContentType;

对我来说更具可读性。

Answer 2

请检查;

关于ActionServlet的html格式的字段名称
使用html-form

Answer 3

检查您的操作类中的内容类型字段是否从uploadContentType重命名为uploadFileContentType。同时将uploadFileName更改为uploadFileFileName。

也改变相应的getter和setter。我不确定它是否导致了这个问题。所以这是一种更多的试错建议。

更新：看来你正在接受GET行动的NPE。

在尝试阻止之前添加以下代码：

if(!servletRequest.getMethod().equalsIgnoreCase("POST")){
   return INPUT;
}

这不是很优雅，但应该适用于此示例。我检查了一下。：）

我使用struts2获取空指针异常上传文件

3 个答案: