通过android向GAE上传文件
我在谷歌应用引擎上工作了三天，终于遇到了这个我无法解决的问题。我做了很多研究，但能找到任何令人信服的东西。M 在设置了我的Google app Engine帐户后，当我调用我的应用程序url“my-app-id.appspot.com/myservlet”时，GAE上的简单Servlet就能够在我的Google bucket中写入.txt文件。相同的代码段如下所示：通过android向GAE上传文件,android,google-app-engine,Android,Google App Engine,我在谷歌应用引擎上工作了三天，终于遇到了这个我无法解决的问题。我做了很多研究，但能找到任何令人信服的东西。M 在设置了我的Google app Engine帐户后，当我调用我的应用程序url“my-app-id.appspot.com/myservlet”时，GAE上的简单Servlet就能够在我的Google bucket中写入.txt文件。相同的代码段如下所示： fetchurl.java DefaultHttpClient hc=new DefaultHtt
fetchurl.java
DefaultHttpClient hc=new DefaultHttpClient();
ResponseHandler <String> res=new BasicResponseHandler();
HttpGet postMethod=new HttpGet("http://my-app-id.appspot.com/uploadservlet");
String response=hc.execute(postMethod,res);
urlString = "http://my-app-id.appspot.com/uploadservlet";
URL url = new URL(urlString);
// Open a HTTP connection to the URL
conn = (HttpURLConnection) url.openConnection();
conn.setConnectTimeout(90000);
// Allow Inputs
conn.setDoInput(true);
// Allow Outputs
conn.setDoOutput(true);
// Don't use a cached copy.
conn.setUseCaches(false);
// Use a post method.
conn.setRequestMethod("POST");
isOK = true;
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Content-Type",
"multipart/form-data;boundary=" + boundary);
DataOutputStream dos = new DataOutputStream(conn.getOutputStream());
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=param1;filename="
+ param1 + "" + lineEnd);
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + lineEnd);
Log.e(Tag, "Param1 are written");
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=param2;filename="
+ param2 + "" + lineEnd);
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + lineEnd);
Log.e(Tag, "Param2 are written");
FileInputStream fileInputStream = new FileInputStream(new File(
path));
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=uploadedfile;filename="
+ path + "" + lineEnd);
dos.writeBytes(lineEnd);
Log.e(Tag, "Headers are written");
// create a buffer of maximum size
int bytesAvailable = fileInputStream.available();
int maxBufferSize = 1000;
// int bufferSize = Math.min(bytesAvailable, maxBufferSize);
byte[] buffer = new byte[bytesAvailable];
// read file and write it into form...
int bytesRead = fileInputStream.read(buffer, 0, bytesAvailable);
while (bytesRead > 0)
{
dos.write(buffer, 0, bytesAvailable);
bytesAvailable = fileInputStream.available();
bytesAvailable = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bytesAvailable);
}
// send multipart form data necesssary after file data...
//dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
Servlet code to handle file upload and save to Google storage--
@MultipartConfig
@SuppressWarnings("serial")
public class SecondtrygoogleServlet extends HttpServlet
{
public static String BUCKETNAME = "androidbucket";
public static String FILENAME = "shikhatry.txt";
private static final long serialVersionUID = 1L;
private static final int THRESHOLD_SIZE = 1024 * 1024 * 3; // 3MB
private static final int MAX_FILE_SIZE = 1024 * 1024 * 40; // 40MB
private static final int REQUEST_SIZE = 1024 * 1024 * 50; // 50MB
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
// checks if the request actually contains upload file
if (!ServletFileUpload.isMultipartContent(request)) {
// if not, we stop here
return;
}
response.setContentType("text/plain");
response.getWriter().println("Hello, test1 world");
// configures some settings
DiskFileItemFactory factory = new DiskFileItemFactory();
factory.setSizeThreshold(THRESHOLD_SIZE);
factory.setRepository(new File(System.getProperty("java.io.tmpdir")));
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setFileSizeMax(MAX_FILE_SIZE);
upload.setSizeMax(REQUEST_SIZE);
java.io.PrintWriter out = response.getWriter( );
try {
// parses the request's content to extract file data
List<?> formItems = upload.parseRequest(request);
out.println("Number of fields: " + formItems.size());
Iterator<?> iter = formItems.iterator();
// iterates over form's fields
while (iter.hasNext())
{
out.println("Inside while loop");
FileItem item = (FileItem) iter.next();
// processes only fields that are not form fields
if (!item.isFormField())
{
String temp = item.getFieldName();
out.println("Parameter Name"+temp);
if(temp.equals("uploadedfile"))
{
String fileName = new File(item.getName()).getName();
FILENAME = fileName+".txt";
out.println("Filename"+fileName);
FileService fileService = FileServiceFactory.getFileService();
GSFileOptionsBuilder optionsBuilder = new GSFileOptionsBuilder()
.setBucket(BUCKETNAME)
.setKey(FILENAME)
.setMimeType("text/html") //audio/mp3 text/html
.setAcl("public_read")
.addUserMetadata("myfield1", "my field value");
AppEngineFile writableFile =
fileService.createNewGSFile(optionsBuilder.build());
// Open a channel to write to it
boolean lock = false;
FileWriteChannel writeChannel =
fileService.openWriteChannel(writableFile, lock);
// Different standard Java ways of writing to the channel
// are possible. Here we use a PrintWriter:
InputStream inputStream = item.getInputStream();
int readBytes = 0;
byte[] buffer = new byte[10000];
while ((readBytes = inputStream.read(buffer, 0, 10000)) != -1)
{
writeChannel.write(ByteBuffer.wrap(buffer));
}
inputStream.close();
writeChannel.closeFinally();
response.getWriter().println("Done writing...");
}
else if(temp.equals("param1"))
{
out.println("Inside param1");
//String param1Val = new File(item.getName()).getName();
//BUCKETNAME = param1Val;
}
else if(temp.equals("param2"))
{
out.println("Inside param2");
//String param2Val = new File(item.getName()).getName();
//BUCKETNAME = param2Val;
}
}
}
request.setAttribute("message", "Upload has been done successfully!");
} catch (Exception ex) {
request.setAttribute("message", "There was an error: " + ex.getMessage());
}
}
Servlet处理文件上传和保存到Google存储的代码--
@多重配置
@抑制警告（“串行”）
公共类SecondtrygoogleServlet扩展了HttpServlet
{
公共静态字符串BUCKETNAME=“androidbucket”；
公共静态字符串FILENAME=“shikhatry.txt”；
私有静态最终长serialVersionUID=1L；
私有静态最终整数阈值\u SIZE=1024*1024*3；//3MB
私有静态最终int MAX_FILE_SIZE=1024*1024*40；//40MB
私有静态最终整数请求_SIZE=1024*1024*50；//50MB
public void doPost（HttpServletRequest请求、HttpServletResponse响应）
抛出ServletException、IOException
{
//检查请求是否确实包含上载文件
如果（！ServletFileUpload.isMultipartContent（请求））{
//如果不是，我们就到此为止
返回；
}
response.setContentType（“文本/普通”）；
response.getWriter（）.println（“您好，test1 world”）；
//配置一些设置
DiskFileItemFactory=新的DiskFileItemFactory（）；
factory.setSizeThreshold（阈值大小）；
setRepository（新文件（System.getProperty（“java.io.tmpdir”））；
ServletFileUpload upload=新的ServletFileUpload（工厂）；
upload.setFileSizeMax（最大文件大小）；
upload.setSizeMax（请求大小）；
java.io.PrintWriter out=response.getWriter（）；
试一试{
//解析请求的内容以提取文件数据
List formItems=upload.parseRequest（请求）；
out.println（“字段数：+formItems.size（））；
迭代器iter=formItems.Iterator（）；
//迭代窗体的字段
while（iter.hasNext（））
{
out.println（“内部while循环”）；
FileItem=（FileItem）iter.next（）；
//仅处理非表单字段的字段
如果（！item.isFormField（））
{
字符串temp=item.getFieldName（）；
out.println（“参数名称”+temp）；
if（临时等于（“上载文件”））
{
字符串文件名=新文件（item.getName（））.getName（）；
文件名=文件名+“.txt”；
out.println（“文件名”+文件名）；
FileService FileService=fileservicecfactory.getFileService（）；
gsfileoptionsbuilderoptionsbuilder=新的GSFileOptionsBuilder（）
.setBucket（BUCKETNAME）
.setKey（文件名）
.setMimeType（“text/html”）//音频/mp3文本/html
.setAcl（“公开阅读”）
.addUserMetadata（“myfield1”、“我的字段值”）；
AppEngineFile可写文件=
fileService.createNewGSFile（optionsBuilder.build（））；
//打开一个通道写入它
布尔锁=假；
文件写入通道写入通道=
openWriteChannel（可写文件，锁）；
//写入通道的不同标准Java方式
//都是可能的。这里我们使用PrintWriter：
InputStream InputStream=item.getInputStream（）；
int readBytes=0；
字节[]缓冲区=新字节[10000]；
而（（readBytes=inputStream.read（缓冲区，0，10000））！=-1）
{
writeChannel.write（ByteBuffer.wrap（缓冲区））；
}
inputStream.close（）；
writeChannel.closeFinally（）；
response.getWriter（）.println（“完成写入…”）；
}
else if（温度等于（“参数1”））
{
out.println（“内部参数1”）；
//字符串param1Val=新文件（item.getName（））.getName（）；
//BUCKETNAME=param1Val；
}
else if（温度等于（“参数2”））
{
out.println（“内部参数2”）；
//字符串param2Val=新文件（item.getName（））.getName（）；
//BUCKETNAME=param2Val；
}
}
}
setAttribute（“消息”，“上传成功！”）；
}捕获（例外情况除外）{
setAttribute（“消息”，“出现错误：”+ex.getMessage（））；
}
}
c、 使用直接写入GCS，然后将上载的文件名发布到您的应用程序。此外，我曾尝试在Amazon Bucket S3和Windows Azure上上载文件，它们提供了直接的方式来完成相同的操作。我在Google上最难找到这一点。奇怪！！感谢您的回复@Stuart..我无法
Servlet code to handle file upload and save to Google storage--
@MultipartConfig
@SuppressWarnings("serial")
public class SecondtrygoogleServlet extends HttpServlet
{
public static String BUCKETNAME = "androidbucket";
public static String FILENAME = "shikhatry.txt";
private static final long serialVersionUID = 1L;
private static final int THRESHOLD_SIZE = 1024 * 1024 * 3; // 3MB
private static final int MAX_FILE_SIZE = 1024 * 1024 * 40; // 40MB
private static final int REQUEST_SIZE = 1024 * 1024 * 50; // 50MB
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
// checks if the request actually contains upload file
if (!ServletFileUpload.isMultipartContent(request)) {
// if not, we stop here
return;
}
response.setContentType("text/plain");
response.getWriter().println("Hello, test1 world");
// configures some settings
DiskFileItemFactory factory = new DiskFileItemFactory();
factory.setSizeThreshold(THRESHOLD_SIZE);
factory.setRepository(new File(System.getProperty("java.io.tmpdir")));
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setFileSizeMax(MAX_FILE_SIZE);
upload.setSizeMax(REQUEST_SIZE);
java.io.PrintWriter out = response.getWriter( );
try {
// parses the request's content to extract file data
List<?> formItems = upload.parseRequest(request);
out.println("Number of fields: " + formItems.size());
Iterator<?> iter = formItems.iterator();
// iterates over form's fields
while (iter.hasNext())
{
out.println("Inside while loop");
FileItem item = (FileItem) iter.next();
// processes only fields that are not form fields
if (!item.isFormField())
{
String temp = item.getFieldName();
out.println("Parameter Name"+temp);
if(temp.equals("uploadedfile"))
{
String fileName = new File(item.getName()).getName();
FILENAME = fileName+".txt";
out.println("Filename"+fileName);
FileService fileService = FileServiceFactory.getFileService();
GSFileOptionsBuilder optionsBuilder = new GSFileOptionsBuilder()
.setBucket(BUCKETNAME)
.setKey(FILENAME)
.setMimeType("text/html") //audio/mp3 text/html
.setAcl("public_read")
.addUserMetadata("myfield1", "my field value");
AppEngineFile writableFile =
fileService.createNewGSFile(optionsBuilder.build());
// Open a channel to write to it
boolean lock = false;
FileWriteChannel writeChannel =
fileService.openWriteChannel(writableFile, lock);
// Different standard Java ways of writing to the channel
// are possible. Here we use a PrintWriter:
InputStream inputStream = item.getInputStream();
int readBytes = 0;
byte[] buffer = new byte[10000];
while ((readBytes = inputStream.read(buffer, 0, 10000)) != -1)
{
writeChannel.write(ByteBuffer.wrap(buffer));
}
inputStream.close();
writeChannel.closeFinally();
response.getWriter().println("Done writing...");
}
else if(temp.equals("param1"))
{
out.println("Inside param1");
//String param1Val = new File(item.getName()).getName();
//BUCKETNAME = param1Val;
}
else if(temp.equals("param2"))
{
out.println("Inside param2");
//String param2Val = new File(item.getName()).getName();
//BUCKETNAME = param2Val;
}
}
}
request.setAttribute("message", "Upload has been done successfully!");
} catch (Exception ex) {
request.setAttribute("message", "There was an error: " + ex.getMessage());
}
}