Google App Engine 文件上传的代码

以前写的Google App Engine上传程序，贴出来上传这部分代码给大家分享下。
不知道现在Google还有没有限制，我以前测试的能上传10M左右。否则就会超时错误。

1. 上传的代码

 

 

    public void  uploadAction(HttpServletRequest req, Page p)
		throws IOException, ServletException {    	
		String path = getHomeUrl(req);
		boolean isMultipart = ServletFileUpload.isMultipartContent(req);
		long id = -1;
		if (isMultipart) {
			ServletFileUpload uploader = new ServletFileUpload();
			uploader.setFileSizeMax(MAX_FILE_SIZE);
			
			try {
				FileItemIterator it = uploader.getItemIterator(req);
				DataFile df = new DataFile();
				df.setDownloadTimes(0);
				
				while (it.hasNext()) {
					FileItemStream item = it.next();

					if(item.isFormField()){
						String value = readString(item.openStream());						
						if(item.getFieldName().equals("categoryId"))
							df.setCategoryId(Integer.valueOf(value));
						else if(item.getFieldName().equals("title"))
							df.setTitle(value);
						else if(item.getFieldName().equals("description"))
							df.setDescription(new Text(value));
					}else{					
						String filename = getFileName(item.getName());
						if(isBlank(filename))
							break;
						
						df.setFilename(filename);
						df.setContentType(ContentType.fetchMatchContentType(filename));
						df.setPostDate(new Date(System.currentTimeMillis()));
						service.add(df);												
						id = df.getId();
						saveFile(item.openStream(), df);
						service.update(df);
					}
				}
								
				if(df.getId() != null){
					String url = path+ "/" + df.getId() + "/show.html";
	    			FileCategory cat = catService.get(df.getCategoryId());
	    			p.put("category", cat == null?"":cat.getName());	    			
					p.put("durl", getHomeUrl(req)+"/file/"+df.getId()+"_"+df.getFilename());    			
					p.put("url", url);
					p.put("file", df);
					p.put("message", "文件上传成功！");
					p.setTemplate("filedata_show.ftl");
				}else{
					p.put("message", "文件上传失败！");
					uploadformAction(req, p);			
				}
			} 
			catch (Exception e) {
				e.printStackTrace();
				p.put("message", "文件上传失败!文件大小不能超过10M!");
				if(id>-1){
					service.delete(id);
					blockService.deleteBlocksOfFile(id);				
				}
				uploadformAction(req, p);			
			}
		}    	
    }
    
	private void saveFile(InputStream in, DataFile df) throws IOException{
		int len, size = 0, totalSize = 0;
		int sn = 1;
		if(in.available() > MAX_FILE_SIZE){
			System.out.println("file to big!");
			throw new IOException("Too Large");		
		}
		while ((len = in.read(buffer)) != -1) {
			if((size + len) > Block_SIZE){//save this block
				DataBlock block = new DataBlock();
				block.setSize(size);
				block.setFileId(df.getId());
				block.setSn(sn++);
				
				byte[] byt = Arrays.copyOf(data, size);
				Blob bo = new Blob(byt);
				block.setData(bo);
				blockService.add(block);
				size = 0;
			}
			
			System.arraycopy(buffer, 0, data, size, len);
			size += len;
			totalSize += len;
		}
		
		if(size > 0){
			DataBlock block = new DataBlock();
			block.setSize(size);
			block.setFileId(df.getId());
			block.setSn(sn++);
			
			byte[] byt = Arrays.copyOf(data, size);
			Blob bo = new Blob(byt);
			block.setData(bo);
			blockService.add(block);			
		}
		
		df.setSize(totalSize);
		in.close();
	}

 

 

2. 下载的代码

 

	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {		
		HttpSession session = req.getSession();
		String seStr = (String)session.getAttribute(Constants.VERIFY_CODE);
		String inputStr = req.getParameter("verify_code");
		
		if(inputStr != null && inputStr.equals(seStr)){
			String url = req.getRequestURI();
			int ind = url.lastIndexOf("/");
			if(ind == -1)
				return;
			
			String temp[] = url.split("/");
			String filename = temp[temp.length - 1];
			ind = filename.indexOf("_");
			String id = filename.substring(0, ind);
			filename = filename.substring(ind + 1);
			
			if(id != null){			
				DataFile df = fservice.get(Long.valueOf(id), false);
				if(df != null){
					resp.setContentType(df.getContentType());
					ServletOutputStream os = resp.getOutputStream();					
					List dbs = service.blocksOfFile(Long.valueOf(id));
					for(DataBlock db : dbs)
						os.write(db.getData().getBytes());
				
					fservice.updateDownloadTimes(Long.valueOf(id));
				}else{
			        Page page = new Page();
			        page.put("home", getHomeUrl(req));
			        page.put("message", "要下载的文件不存在!");
	    			page.setTemplate("filedata_error.ftl");
	    	        Template t = cfg.getTemplate(page.getTemplate());
	                
	    	        Writer out = new BufferedWriter(
	    	        		new OutputStreamWriter(
	    	        				resp.getOutputStream(), t.getEncoding()));
	    	        resp.setContentType("text/html; charset=" + t.getEncoding());
	    	        resp.setHeader("Cache-Control", "no-cache");
	    	        resp.setHeader("Pragma", "no-cache");
	    	        resp.setHeader("Expires", "Thu, 01 Dec 2010 00:00:00 GMT");
	    	            
	    	        try {
	    	        	t.process(page.getRoot(), out);
	    	        	out.flush();
	    	        } catch (TemplateException e) {
	    	        	e.printStackTrace();
	    	        	resp.sendRedirect("error.htm");
	    	        }	    			
				}
			}			
		}else{
			doGet(req, resp);
		}
						
	}

 3. 和freemarker集成的Controller

 

import java.io.*;
import java.lang.reflect.Method;

import javax.servlet.*;
import javax.servlet.http.*;

import com.hchen.pubshare.service.FileCategoryService;
import com.hchen.pubshare.service.impl.FileCategoryServiceImpl;
import com.hchen.pubshare.util.Page;

import freemarker.template.*;

public abstract class ControllerServlet extends HttpServlet {
	private static final long serialVersionUID = -754687385885208233L;
	private Configuration cfg; 
	private FileCategoryService catService = new FileCategoryServiceImpl();
	
    public void init() {
        cfg = new Configuration();
        cfg.setServletContextForTemplateLoading(
                getServletContext(), "WEB-INF/templates");
        // - Set update dealy to 0 for now, to ease debugging and testing
        cfg.setTemplateUpdateDelay(0);
        // - Set error handler for debugging HTML templates
//        cfg.setTemplateExceptionHandler(
//                TemplateExceptionHandler.HTML_DEBUG_HANDLER);
        // - Use beans wrapper
        cfg.setObjectWrapper(ObjectWrapper.BEANS_WRAPPER);
        // - Set default charset
        cfg.setDefaultEncoding("UTF-8");
        cfg.setDateTimeFormat("yyyy-MM-dd HH:mm:ss");
        cfg.setNumberFormat("############");
    }
    
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        doGet(req, resp);
    }
    
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {
    	try{
    		String action = req.getServletPath();
    		if (action == null) action = "index";
    		if (action.lastIndexOf("/") != -1) action = action.substring(action.lastIndexOf("/") + 1);
    		if (action.lastIndexOf(".") != -1) action = action.substring(0, action.lastIndexOf("."));

    		Method actionMethod = getClass().getMethod(action + "Action",
        						new Class[]{HttpServletRequest.class, Page.class});
    		Page page = new Page();
    		page.put("message", "");
    		page.put("home", getHomeUrl(req));
    		processRequestParameters(req.getServletPath(), action, page);
    		actionMethod.invoke(this, new Object[]{req, page});
        
    		if (page.getTemplate() != null) { // show a page with a template
    			Template t = cfg.getTemplate(page.getTemplate());
    			Writer out = new BufferedWriter(
                    new OutputStreamWriter(
                            resp.getOutputStream(), t.getEncoding()));
    			resp.setContentType("text/html; charset=" + t.getEncoding());
    			resp.setHeader("Cache-Control", "no-cache");
    			resp.setHeader("Pragma", "no-cache");
    			resp.setHeader("Expires", "Thu, 01 Dec 2010 00:00:00 GMT");
            
                t.process(page.getRoot(), out);
                out.flush();
    		} else if (page.getForward() != null) { // forward request
    			if(page.isDispatch()){
    				RequestDispatcher rd = req.getRequestDispatcher(page.getForward());
    				rd.forward(req, resp);            
    			}else{
    				resp.sendRedirect(page.getForward());
    			}
    		} else { // Ops!
    			throw new ServletException("The action didn't specified command.");
    		}
    	}catch(Exception ex){
    		ex.printStackTrace();
    		resp.sendRedirect("error.htm");
    	}    	
    }
    
    public static String noNull(String s) {
        return s == null ? "" : s;
    }
    
    public static boolean isBlank(String s) {
        return s == null || s.trim().length() == 0; 
    }    
    
    public String getHomeUrl(HttpServletRequest req){
		String path = null;
		if (req.getServerPort() == 80 )
			path="http://"+req.getServerName();
		else 
			path="http://"+req.getServerName()+":"+req.getServerPort();    	
		
		return path;
    }
    
	public void processRequestParameters(String path, String action, Page page){
		if(isBlank(action))
			return;
		String temps[] = path.split("/");
		int len = temps.length;
		if(action.equals("show")){
			if(temps.length > 2) page.addReqParameter("id", temps[len - 2]);
		}else if(action.equals("list")){
			if(temps.length > 3){
				page.addReqParameter("dir", temps[len - 3]);
				page.addReqParameter("offset", temps[len - 2]);
			}
		}
	}
}

 

完整代码上传到 google code了，以前做的一个文件上传的Google App，现在不弄这个了。

 

svn checkout http://pubshare.googlecode.com/svn/trunk/ pubshare-read-only