import org.apache.commons.io.FileCleaningTracker; //导入依赖的package包/类
private static FileItemFactory getDefaultFileItemFactory(final int threshold)
{
    final DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();
    diskFileItemFactory.setFileCleaningTracker( new FileCleaningTracker() );
    diskFileItemFactory.setSizeThreshold( threshold );
    return diskFileItemFactory;
}
 

import org.apache.commons.io.FileCleaningTracker; //导入依赖的package包/类
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

    boolean isMultipart = ServletFileUpload.isMultipartContent(req);
    HttpSession session = req.getSession(false);
    Integer userId = (int)session.getAttribute("id_user");
    Integer orderId = (int)session.getAttribute("currentOrder");
    PrintWriter out = resp.getWriter();
    JsonObject jsonObject = new JsonObject();

    if(isMultipart && userId != -1 && orderId != -1){
        // Create a factory for disk-based file items
        DiskFileItemFactory factory = new DiskFileItemFactory();
        // Configure a repository (to ensure a secure temp location is used)
        ServletContext servletContext = this.getServletConfig().getServletContext();

        FileCleaningTracker tracker = FileCleanerCleanup.getFileCleaningTracker(servletContext);
        factory.setFileCleaningTracker(tracker);
        File repository = (File) servletContext.getAttribute("javax.servlet.context.tempdir");
        factory.setRepository(repository);

        // Create a new file upload handler
        ServletFileUpload upload = new ServletFileUpload(factory);

        try {
            List<FileItem> items = upload.parseRequest(req);

            for (FileItem imageFile : items){
                byte[] imageByte = imageFile.get();
                Order order = new Order();
                order.setId(orderId);
                Image image = new Image();
                image.setDataimage(imageByte);
                image.setOrder(order);
                new ImageDBManager().create(image);
            }
            jsonObject.addProperty("success", true);

        } catch (FileUploadException e) {
            jsonObject.addProperty("success", false);
            e.printStackTrace();
        }
    } else {
        jsonObject.addProperty("success", false);
    }

    out.append(jsonObject.toString());
    out.flush();


}
 

import org.apache.commons.io.FileCleaningTracker; //导入依赖的package包/类
/**
 * 设置临时文件跟踪器，参考：{@link DiskFileItemFactory#setFileCleaningTracker(FileCleaningTracker)}
 *
 * @param factoryCleaningTracker
 */
public void setFactoryCleaningTracker(
        FileCleaningTracker factoryCleaningTracker)
{
    this.factoryCleaningTracker=factoryCleaningTracker;
}
 

import org.apache.commons.io.FileCleaningTracker; //导入依赖的package包/类
/**
 * Sets the tracker, which is responsible for deleting temporary
 * files.
 *
 * @param pTracker An instance of {@link FileCleaningTracker},
 *   which will from now on track the created files, or null
 *   (default), to disable tracking.
 */
public void setFileCleaningTracker(FileCleaningTracker pTracker) {
    fileCleaningTracker = pTracker;
}
 

import org.apache.commons.io.FileCleaningTracker; //导入依赖的package包/类
/**
 * Create a new {@link org.apache.commons.fileupload.disk.DiskFileItem}
 * instance from the supplied parameters and the local factory
 * configuration.
 *
 * @param fieldName   The name of the form field.
 * @param contentType The content type of the form field.
 * @param isFormField <code>true</code> if this is a plain form field;
 *                    <code>false</code> otherwise.
 * @param fileName    The name of the uploaded file, if any, as supplied
 *                    by the browser or other client.
 *
 * @return The newly created file item.
 */
public FileItem createItem(String fieldName, String contentType,
        boolean isFormField, String fileName) {
    DiskFileItem result = new DiskFileItem(fieldName, contentType,
            isFormField, fileName, sizeThreshold, repository);
    FileCleaningTracker tracker = getFileCleaningTracker();
    if (tracker != null) {
        tracker.track(result.getTempFile(), result);
    }
    return result;
}
 

import org.apache.commons.io.FileCleaningTracker; //导入依赖的package包/类
/**
 * Returns the instance of {@link FileCleaningTracker}, which is
 * associated with the given {@link ServletContext}.
 *
 * @param pServletContext The servlet context to query
 * @return The contexts tracker
 */
public static FileCleaningTracker
        getFileCleaningTracker(ServletContext pServletContext) {
    return (FileCleaningTracker)
        pServletContext.getAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE);
}
 

import org.apache.commons.io.FileCleaningTracker; //导入依赖的package包/类
/**
 * Sets the instance of {@link FileCleaningTracker}, which is
 * associated with the given {@link ServletContext}.
 *
 * @param pServletContext The servlet context to modify
 * @param pTracker The tracker to set
 */
public static void setFileCleaningTracker(ServletContext pServletContext,
        FileCleaningTracker pTracker) {
    pServletContext.setAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE, pTracker);
}
 

import org.apache.commons.io.FileCleaningTracker; //导入依赖的package包/类
/**
 * Called when the web application is initialized. Does
 * nothing.
 *
 * @param sce The servlet context, used for calling
 *   {@link #setFileCleaningTracker(ServletContext, FileCleaningTracker)}.
 */
public void contextInitialized(ServletContextEvent sce) {
    setFileCleaningTracker(sce.getServletContext(),
            new FileCleaningTracker());
}
 

import org.apache.commons.io.FileCleaningTracker; //导入依赖的package包/类
/**
 * Returns the tracker, which is responsible for deleting temporary
 * files.
 *
 * @return An instance of {@link FileCleaningTracker}, or null
 *   (default), if temporary files aren't tracked.
 */
public FileCleaningTracker getFileCleaningTracker() {
    return fileCleaningTracker;
}
 

import org.apache.commons.io.FileCleaningTracker; //导入依赖的package包/类
/**
 * 获取临时文件跟踪器，参考：{@link DiskFileItemFactory#getFileCleaningTracker()}
 *
 * @return
 */
public FileCleaningTracker getFactoryCleaningTracker()
{
    return factoryCleaningTracker;
}