急，action类上传文件时报空指针错误，错误如下，专家们帮我看看

错误显示如下：
java.lang.NullPointerException
java.io.File.(File.java:360)
com.action.uploadtAction.execute(uploadtAction.java:131)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

出错行：
FileUtils.copyFile(upload, new File(file, uploadFileName));

源码：
public class uploadtAction extends ActionSupport {
private File uploadt;
private String uploadContentType;
private String uploadFileName;
private String result;
private String className;
private int id;
private String title;
private String descri;
private String time;
private String pic;

public String getClassName() {
    return className;
}

public void setClassName(String className) {
    this.className = className;
}

public Integer getId() {
    return id;
}

public void setId(Integer id) {
    this.id = id;
}

public String getDescri() {
    return descri;
}

public void setDescri(String descri) {
    this.descri = descri;
}

public String getTitle() {
    return title;
}

public void setTitle(String title) {
    this.title = title;
}

public String getTime() {
    return time;
}

public void setTime(String time) {
    this.time = time;
}

public String getPic() {
    return pic;
}

public void setPic(String pic) {
    this.pic = pic;
}

public File getUploadt() {
    return uploadt;
}

public void setUploadt(File upload) {
    this.uploadt = upload;
}

public String getUploadContentType() {
    return uploadContentType;
}

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

public String getUploadFileName() {
    return uploadFileName;
}

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

public String getResult() {
    return result;
}

public void setResult(String result) {
    this.result = result;
}

// 实现execute方法
public String execute() throws Exception {
    HttpServletRequest reqeust = ServletActionContext.getRequest();
    HttpServletResponse response = ServletActionContext.getResponse();

    String path = ServletActionContext.getServletContext().getRealPath(
            "/img");
    File file = new File(path);
    if (!file.exists()) {
        file.mkdir();

    }
    FileUtils.copyFile(uploadt, new File(file, uploadFileName));
    result = "上传成功";

    news n = new news();
    newsDao nDao = new newsDao();
    Date date = new Date();

    DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
    String time = format.format(date);
    String className = (String) reqeust.getParameter("r");
    String title = (String) reqeust.getParameter("title");
    String descri = (String) reqeust.getParameter("descri");
    String pic = "img/" + uploadFileName;; // 获取表单传过来的数据

    n.setClassName(className);
    n.setTitle(title);
    n.setTime(time);
    n.setDescri(descri);
    n.setPic(pic);

    try {
        // 执行数据库查询操作
        nDao.addNews(n);

    } catch (SQLException e) {
        e.printStackTrace();
    }
    // }

    return SUCCESS;

}

struts.xml

uploadNews.jsp
error.jsp

jpg,jpeg,JPG,JPEG
10M

        <interceptor-ref name="defaultStack"></interceptor-ref>

    </action>

struts.xml如下：

uploadNews.jsp
error.jsp

jpg,jpeg,JPG,JPEG
10M

        <interceptor-ref name="defaultStack"></interceptor-ref>

    </action>

为什么xml显示不了