package framework.fileUpload;

import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileUpload;
import org.apache.commons.fileupload.FileUploadBase;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.springframework.web.multipart.MaxUploadSizeExceededException;
import org.springframework.web.multipart.MultipartException;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;

/**
 * 文件上传
 * 
 * @author liuyajun, 8384503@qq.com
 * @date 2016年1月19日
 * @time 下午4:34:06
 */
public class MyMultipartResolver extends CommonsMultipartResolver {

	private HttpServletRequest request;

	protected FileUpload newFileUpload(FileItemFactory fileItemFactory) {
		ServletFileUpload upload = new ServletFileUpload(fileItemFactory);
		upload.setSizeMax(-1);
		if (request != null) {
			HttpSession session = request.getSession();
			FileUploadProgressListener progressListener = 
					new FileUploadProgressListener(session);
			upload.setProgressListener(progressListener);
		}
		return upload;
	}

	public MultipartHttpServletRequest resolveMultipart(
			HttpServletRequest request) throws MultipartException {
		// 获取到request,要用到session
		this.request = request;
		return super.resolveMultipart(request);
	}

	@Override
	public MultipartParsingResult parseRequest(
			HttpServletRequest request) throws MultipartException {
		HttpSession session = request.getSession();
		String encoding = determineEncoding(request);
		FileUpload fileUpload = prepareFileUpload(encoding);
		FileUploadProgressListener progressListener = 
				new FileUploadProgressListener(session);
		fileUpload.setProgressListener(progressListener);
		try {

			List<FileItem> fileItems = 
					((ServletFileUpload) fileUpload).parseRequest(request);
			return parseFileItems(fileItems, encoding);
		} catch (FileUploadBase.SizeLimitExceededException ex) {
			progressListener.tooMax(fileUpload.getSizeMax());
			throw new MaxUploadSizeExceededException(fileUpload.getSizeMax(), ex);
		} catch (FileUploadException ex) {
			throw new MultipartException("Could not parse multipart servlet request", ex);
		}
	}
}