2012-12-12 6 views
6

Il mio progetto contiene solo un semplice modulo di caricamento file e il reindirizzamento per visualizzarlo. Posso caricare qualsiasi file inferiore a 50 KB, ma quando carico alcuni file più grandi di 100 KB, genera IO Eccezione dal motore dell'app. Non sono sicuro di dove sia il problema. Qualcuno sa come aumentare la dimensione del file che posso caricare sullo spazio di archiviazione di Google Cloud attraverso la registrazione di moduli nel motore di app? la dimensione del file correttamente inferiore a 10 MB è OK. Qualsiasi frammento di codice sarebbe apprezzato in modo particolare. Grazie.Perché non riesco a caricare file su Google Cloud Storage con dimensioni superiori a 100 KByte tramite il motore di app?

java.io.IOException 
    at com.google.appengine.api.files.FileServiceImpl.translateException(FileServiceImpl.java:615) 
    at com.google.appengine.api.files.FileServiceImpl.makeSyncCall(FileServiceImpl.java:588) 
    at com.google.appengine.api.files.FileServiceImpl.append(FileServiceImpl.java:535) 
    at com.google.appengine.api.files.FileServiceImpl.append(FileServiceImpl.java:289) 
    at com.google.appengine.api.files.FileWriteChannelImpl.write(FileWriteChannelImpl.java:57) 
    at com.google.appengine.api.files.FileWriteChannelImpl.write(FileWriteChannelImpl.java:46) 
    at java.nio.channels.Channels.write(Channels.java:80) 
    at java.nio.channels.Channels.access$000(Channels.java:64) 
    at java.nio.channels.Channels$1.write(Channels.java:151) 
    at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82) 
    at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140) 
    at storefile.StorageService.storeFile(StorageService.java:46) 
    at storefile.UploadServlet.doPost(UploadServlet.java:46) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) 

seguito è il mio codice: upload.html

<html> 
<head> 
<meta http-equiv="content-type" content="text/html; charset=UTF-8"> 
<title>Hello App Engine</title> 
</head> 

<body> 
    <h1>Hello App Engine!</h1> 
    <form action="/upload" method="post" enctype="multipart/form-data"> 
     <p>File<input type="file" name="file" /> </p> 
     <p> <input type="submit"value="upload" /> <input type="reset" value="reset"/> </p> 
    </form> 
    </body> 
</html> 

uploadServlet.java

import java.io.BufferedInputStream; 
import java.io.IOException; 
import java.io.InputStream; 

import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 

import org.apache.commons.fileupload.FileItemIterator; 
import org.apache.commons.fileupload.FileItemStream; 
import org.apache.commons.fileupload.servlet.ServletFileUpload; 

import com.google.appengine.api.blobstore.BlobKey; 


public class UploadServlet extends HttpServlet{ 

    private static final long serialVersionUID = 1L; 
    private StorageService storage = new StorageService(); 
    private static int BUFFER_SIZE =1024 * 1024* 10; 
    @Override 
    public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException { 

     resp.setContentType("text/plain"); 
     resp.getWriter().println("Now see here your file content, that you have uploaded on storage.."); 

     ServletFileUpload upload = new ServletFileUpload(); 
     FileItemIterator iter; 
    try { 
    iter = upload.getItemIterator(req); 
    while (iter.hasNext()) { 
      FileItemStream item = iter.next(); 
      String fileName = item.getName(); 
      String mime = item.getContentType(); 

      storage.init(fileName, mime); 
      InputStream is = new BufferedInputStream(item.openStream()); 

      byte[] b = new byte[BUFFER_SIZE]; 
      int readBytes = is.read(b, 0, BUFFER_SIZE); 

      while (readBytes != -1) { 
       storage.storeFile(b, readBytes); 
       readBytes = is.read(b, 0, readBytes); 
      } 

      is.close(); 
      storage.destroy(); 

     resp.getWriter().println("File uploading done"); 

      // resp.getWriter().println("READ:" + storage.readTextFileOnly(fileName)); 
      BlobKey key = storage.getBlobkey(fileName); 
      if (key != null) { 
       resp.sendRedirect("/serve?blob-key=" + key.getKeyString()); 
      } else { 
       resp.sendRedirect("/"); 
      } 


     } 
    } catch (Exception e) { 
    e.printStackTrace(resp.getWriter()); 
    System.out.println("Exception::"+e.getMessage()); 
    e.printStackTrace(); 
    } 
} 

} 

StorageService.java

import java.io.BufferedOutputStream; 
import java.io.BufferedReader; 
import java.nio.channels.Channels; 
import java.util.logging.Logger; 

import com.google.appengine.api.blobstore.BlobKey; 
import com.google.appengine.api.blobstore.BlobstoreService; 
import com.google.appengine.api.blobstore.BlobstoreServiceFactory; 
import com.google.appengine.api.files.AppEngineFile; 
import com.google.appengine.api.files.FileReadChannel; 
import com.google.appengine.api.files.FileService; 
import com.google.appengine.api.files.FileServiceFactory; 
import com.google.appengine.api.files.FileWriteChannel; 
import com.google.appengine.api.files.GSFileOptions.GSFileOptionsBuilder; 

public class StorageService { 

public static final String BUCKET_NAME = "aaaa"; 

private FileWriteChannel writeChannel = null; 
FileService fileService = FileServiceFactory.getFileService(); 

private BufferedOutputStream bos = null; 
private static final Logger log = Logger.getLogger(StorageService.class.getName()); 
private BlobstoreService blobstoreService = BlobstoreServiceFactory.getBlobstoreService(); 
public void init(String fileName, String mime) throws Exception { 
System.out.println("Storage service:init() method: file name:"+fileName+" and mime:"+mime); 
log.info("Storage service:init() method: file name:"+fileName+" and mime:"+mime); 

    GSFileOptionsBuilder builder = new GSFileOptionsBuilder() 
      .setAcl("public_read") 
      .setBucket(BUCKET_NAME) 
      .setKey(fileName) 
      .setMimeType(mime); 
    AppEngineFile writableFile = fileService.createNewGSFile(builder.build()); 

    boolean lock = true; 
    writeChannel = fileService.openWriteChannel(writableFile, lock); 
    bos = new BufferedOutputStream(Channels.newOutputStream(writeChannel)); 
} 

public void storeFile(byte[] b, int readSize) throws Exception { 
    bos.write(b,0,readSize); 
    bos.flush(); 
} 

    public void destroy() throws Exception { 
    log.info("Storage service: destroy() method"); 
     bos.close(); 
     writeChannel.closeFinally(); 
    } 
    public BlobKey getBlobkey (String filename) { 
     BlobKey bk = blobstoreService.createGsBlobKey("/gs/aaaa/"+filename); 
     return bk; 
    } 

} 

fileserve.java

import java.io.IOException; 

import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 

import com.google.appengine.api.blobstore.BlobKey; 
import com.google.appengine.api.blobstore.BlobstoreService; 
import com.google.appengine.api.blobstore.BlobstoreServiceFactory; 

public class fileserve extends HttpServlet { 
    private BlobstoreService blobstoreService = BlobstoreServiceFactory.getBlobstoreService(); 

public void doGet(HttpServletRequest req, HttpServletResponse res) 
    throws IOException { 
     BlobKey blobKey = new BlobKey(req.getParameter("blob-key")); 
     blobstoreService.serve(blobKey, res); 
    } 
} 

web.xml

<?xml version="1.0" encoding="utf-8" standalone="no"?><web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.5" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> 
    <servlet> 
     <servlet-name>upload</servlet-name> 
     <servlet-class>storefile.UploadServlet</servlet-class> 
    </servlet> 
    <servlet-mapping> 
     <servlet-name>upload</servlet-name> 
     <url-pattern>/upload</url-pattern> 
    </servlet-mapping> 
    <servlet> 
     <servlet-name>serve</servlet-name> 
     <servlet-class>storefile.fileserve</servlet-class> 
    </servlet> 
    <servlet-mapping> 
     <servlet-name>serve</servlet-name> 
     <url-pattern>/serve</url-pattern> 
    </servlet-mapping> 
    <welcome-file-list> 
     <welcome-file>index.jsp</welcome-file> 
    </welcome-file-list> 

risposta

7

Provare a cambiare la seconda is.read da:

readBytes = is.read(b, 0, readBytes); 

a:

readBytes = is.read(b, 0, BUFFER_SIZE); 

Se ad un certo punto si sta leggendo più veloce dei dati è disponibile, readBytes è impostato su 0 e rimane per sempre a questo valore, perché in pratica sta facendo is.read(b, 0, 0).

Ancora meglio - si dovrebbe verificare se ci sono dati da scrivere:

while (readBytes != -1) { 
    if(readBytes > 0) 
     storage.storeFile(b, readBytes); 
    readBytes = is.read(b, 0, BUFFER_SIZE); 
}