我知道我可以使用multipart / form POST请求一次将1个文件上传到AppEngine. AppEngine也支持uploading multiple files,但你必须做一些运行的JSP东西才能工作.

我有一个应用程序,要求我上传一些表单数据,2个图像和3个文本字段.这可以通过AppEngine完成吗？我一直在努力寻找有关这方面的信息,但这很难解决我需要的灵活性.我将把数据存储在blob存储/数据存储中.

我需要一个Java解决方案.

这是我的POST方法的签名：

import javax.ws.rs.Consumes;

import javax.ws.rs.POST;

@POST

@Consumes(MediaType.MULTIPART_FORM_DATA)

public void post(

@Context HttpServletRequest request,

@Context HttpServletResponse response)

throws FileUploadException, IOException {}

如果确实需要,可以复制和粘贴Java Servlet.以上是问题和相关的servlet片段.

import java.io.BufferedReader;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.nio.channels.Channels;

import java.util.Iterator;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.ws.rs.Consumes;

import javax.ws.rs.POST;

import javax.ws.rs.Path;

import javax.ws.rs.core.Context;

import javax.ws.rs.core.MediaType;

import org.apache.commons.fileupload.FileItemHeaders;

import org.apache.commons.fileupload.FileItemIterator;

import org.apache.commons.fileupload.FileItemStream;

import org.apache.commons.fileupload.FileUploadException;

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

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;

@Path("/upload")

public class FileUploadServlet {

private BlobstoreService blobstoreService = BlobstoreServiceFactory

.getBlobstoreService();

@POST

@Consumes(MediaType.MULTIPART_FORM_DATA)

public void post(@Context HttpServletRequest request,

@Context HttpServletResponse response) throws FileUploadException,

IOException {

final ServletFileUpload upload = new ServletFileUpload();

final FileItemIterator fileIter = upload.getItemIterator(request);

while (fileIter.hasNext()) {

final FileItemStream item = fileIter.next();

String name = item.getName();

String fieldName = item.getFieldName();

String contentType = item.getContentType();

Log.d("Name = " + name);

Log.d("Field-Name = " + fieldName);

Log.d("Content-Type = " + contentType);

FileItemHeaders headers = item.getHeaders();

if(headers != null) {

Iterator it = (Iterator)headers.getHeaderNames();

while(it.hasNext()) {

String h = it.next();

Log.d(h + " = " + headers.getHeader(h));

}

}

if (item.isFormField()) {

// Nothing

} else {

RawImageData data = new RawImageData();

data.load(item.openStream());

// RawImageData reads the stream and stores it into a large byte[] called data.imageData

ByteBuffer bb = ByteBuffer.wrap(data.imageData);

FileService fs = FileServiceFactory.getFileService();

AppEngineFile file = fs.createNewBlobFile(contentType);

FileWriteChannel write = fs.openWriteChannel(file, true);

write.write(bb);

write.closeFinally();

String path = file.getFullPath();

Log.d(path);

// Later, read from the file using the file API

boolean lock = false; // Let other people read at the same time

FileReadChannel readChannel = fs.openReadChannel(file,

false);

// CRASHES WITH java.nio.charset.IllegalCharsetNameException: image/jpeg

// contentType = "image/jpeg"

// Again, different standard Java ways of reading from the

// channel.

BufferedReader reader = new BufferedReader(Channels.newReader(readChannel, contentType));

readChannel.close();

}

}

response.setContentType("text/html");

response.getOutputStream().write("success".getBytes());

}

}

完全例外：

WARNING: /api/upload

java.nio.charset.IllegalCharsetNameException: image/jpeg

at java.nio.charset.Charset.checkName(Charset.java:284)

at java.nio.charset.Charset.lookup2(Charset.java:458)

at java.nio.charset.Charset.lookup(Charset.java:437)

at java.nio.charset.Charset.forName(Charset.java:502)

at java.nio.channels.Channels.newReader(Channels.java:381)

at com.futonredemption.starstarstar.FileUploadServlet.post(FileUploadServlet.java:96)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

blah blah blah