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Java 1.6 Encode Base64 inputStream of a Excel file byte[] stream

I have been searching the web for this particular problem. Maybe i'm doing something wrong or i'm missing something here...
So i'm trying to convert a File Stream ( an Excel file ) -> mimetype ( application/octet-stream or application/vnd.ms-excel ) doesn´t matter...to a Base64 encoded string.
The reason i'm doing this is because i want to provide the File in a REST API inside a JSON object for later decoding in the browser the base64 string and download the file.
When I receivethe InputStream and save to the disk everything works fine...
Even when i use POSTMAN to get the FILE if I save the file it opens in Excel with all the right data.
THE CODE -> Used this simple example to download a file from a URL
URL url = new URL(fileURL);
HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
//etc...i get response code OK(200) get file name etc
// opens input stream from the HTTP connection
InputStream inputStream = httpConn.getInputStream();
String saveFilePath1 = "C:\\test1.xlsx";
String saveFilePath2 = "C:\\test2.xlsx";
FileOutputStream outputStream = new FileOutputStream(saveFilePath1);
int bytesRead = -1;
byte[] buffer = new byte[BUFFER_SIZE];
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
//FOR TESTING PURPOSES AT THIS POINT I HAVE SAVED THE STREAM INTO
//**test1.xlsx** SUCCESSFULLY and opens into excel and everything
//is fine.
//THE PROBLEM RESIDES HERE IN THIS NEXT PIECE OF CODE
//import org.apache.commons.codec.binary.Base64;
//I try to encode the string to Base64
String encodedBytesBase64 = Base64.encodeBase64String(buffer);
//WHEN I DO THE DECODE AND WRITE THE BYTES into test2.xlsx this file doesn´t work...
FileOutputStream fos = new FileOutputStream(saveFilePath2);
byte[] bytes = Base64.decodeBase64(encodedBytesBase64);
fos.write(bytes);
//Close streams from saved file test2
fos.close();
//Close streams from saved file test1
outputStream.close();
inputStream.close();
I even took the string to check if it is a valid Base64 String, which it is accordind to this site -> Base64 Validator
But when i try to decode the string in the same website it tells me there's a different encoding:
Is it possible this is the problem ?

I think you can ignore those warnings. Rather, the issue is here:
int bytesRead = -1;
byte[] buffer = new byte[BUFFER_SIZE];
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
:
String encodedBytesBase64 = Base64.encodeBase64String(buffer);
As you can see in the first part, you are reusing buffer to read the input stream and write to the output stream. If this loops around more than once, buffer will be overwritten with the next chunk of data from the input stream. So, when you are encoding buffer, you are only using the last chunk of the file.
The next problem is that when you are encoding, you are encoding the full buffer array, ignoring the bytesRead.
One option might be to read the inputStream and write it to a ByteArrayOutputStream, and then encode that.
int bytesRead = -1;
byte[] buffer = new byte[BUFFER_SIZE];
ByteArrayOutputStream array = new ByteArrayOutputStream();
while ((bytesRead = inputStream.read(buffer)) != -1) {
array.write(buffer, 0, bytesRead);
}
String encoded = Base64.encodeBase64String(array.toByteArray());

Download large video file getting corrupted

In server side code, I have set buffer size and content length as File.length() and then Opened File using FileInputStream.
Later fetching output stream using HttpResponse.getOutputStream() and dumping bytes of data that is read using FileInputStream
I am using Apache Tomcat 7.0.52, Java 7
On Client
File Downloader.java
URL url = new URL("myFileURL");
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
con.setDoInput(true);
con.setConnectTimeout(10000);
con.setReadTimeout(10000);
con.setRequestMethod("GET");
con.setUseCaches(false);
con.setRequestProperty("User-Agent", "Mozilla/5.0");
con.connect();
FileOutputStream fos = new FileOutputStream("filename");
if(con.getResponseCode()==200){
InputStream is = con.getInputStream();
int readVal;
while((readVal=is.read())!=-1) fos.write(readVal);
}
fos.flush()
fos.close();
So above code failed to download large file.
On client using Java 7

Can You try this
FileOutputStream outputStream = new FileOutputStream(fileName);
int bytesRead;
byte[] buffer = new byte[1024];
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
Quoting from https://stackoverflow.com/a/45453874/4121845
Because you only want to write data that you actually read. Consider the case where the input consists of N buffers plus one byte. Without the len parameter you would write (N+1)*1024 bytes instead of N*1024+1 bytes. Consider also the case of reading from a socket, or indeed the general case of reading: the actual contract of InputStream.read() is that it transfers at least one byte, not that it fills the buffer. Often it can't, for one reason or another.

fos.flush();
} finally {
fos.close();
con.close();
}

How can I put a downloadable file into the HttpServletResponse?

I have the following problem: I have an HttpServlet that create a file and return it to the user that have to receive it as a download
byte[] byteArray = allegato.getFile();
InputStream is = new ByteArrayInputStream(byteArray);
Base64InputStream base64InputStream = new Base64InputStream(is);
int chunk = 1024;
byte[] buffer = new byte[chunk];
int bytesRead = -1;
OutputStream out = new ByteArrayOutputStream();
while ((bytesRead = base64InputStream.read(buffer)) != -1) {
out.write(buffer, 0, bytesRead);
}
As you can see I have a byteArray object that is an array of bytes (byte[] byteArray) and I convert it into a file in this way:
First I convert it into an InputStream object.
Then I convert the InputStream object into a Base64InputStream.
Finally I write this Base64InputStream on a ByteArrayOutputStream object (the OutputStream out object).
I think that up to here it should be ok (is it ok or am I missing something in the file creation?)
Now my servlet have to return this file as a dowload (so the user have to receive the download into the browser).
So what have I to do to obtain this behavior? I think that I have to put this OutputStream object into the Servlet response, something like:
ServletOutputStream stream = res.getOutputStream();
But I have no idea about how exactly do it? Have I also to set a specific MIME type for the file?

It's pretty easy to do.
byte[] byteArray = //your byte array
response.setContentType("YOUR CONTENT TYPE HERE");
response.setHeader("Content-Disposition", "filename=\"THE FILE NAME\"");
response.setContentLength(byteArray.length);
OutputStream os = response.getOutputStream();
try {
os.write(byteArray , 0, byteArray.length);
} catch (Exception excp) {
//handle error
} finally {
os.close();
}
EDIT:
I've noticed that you are first decoding your data from base64, the you should do the following:
OutputStream os = response.getOutputStream();
byte[] buffer = new byte[chunk];
int bytesRead = -1;
while ((bytesRead = base64InputStream.read(buffer)) != -1) {
os.write(buffer, 0, bytesRead);
}
You do not need the intermediate ByteArrayOutputStream

With org.apache.commons.compress.utils.IOUtils you can just "copy" from one file or stream (e.g. your base64InputStream) to the output stream:
response.setContentType([your file mime type]);
IOUtils.copy(base64InputStream, response.getOutputStream());
response.setStatus(HttpServletResponse.SC_OK);
You'll find that class here https://mvnrepository.com/artifact/org.apache.commons/commons-compress
A similar class (also named IOUtils) is also in Apache Commons IO (https://mvnrepository.com/artifact/commons-io/commons-io).

Transfering file over a socket in ftp protocol

I have a problem to send a file(not necessarily a txt file) over a socket.I have 2 classes:Server,Client.When I read from a socket output stream and want to write the bytes in a file,it looks working but when i open the file it has nothing.(corrupted showing the size=0 kb).I also want it to transfer all kind of file over a socket.I don't want to use appache commons net.
Here is my code
Server class
FileOutputStream toFile1 = new FileOutputStream(f);
BufferedOutputStream toFile= new BufferedOutputStream(toFile1);
BufferedInputStream bis=new BufferedInputStream(incoming.getInputStream());
byte[]buffer=new byte[2048];
int bytesRead=0;
while((bytesRead = bis.read(buffer)) >= 0)
{
toFile.write(buffer, 0, bytesRead);
}
toFile.close();
toFile1.close();
bis.close();
out.println("226 Connection Closed");
out.flush();
}
Client class
BufferedOutputStream output = new BufferedOutputStream(socket.getOutputStream());
byte[] buffer = new byte[60*2024];
int bytesRead = 0;
while ((bytesRead = input.read(buffer,0,60*1024)) != -1) {
output.write(buffer, 0, bytesRead);
}

The only way that can happen with that code is if you are sending a zero length file, or maybe reading from a file input stream that is already positioned at EOF, or else you are looking at the wrong file afterwards.

Download file from ftp server

i am writing a small android application which requires some data which is stored on my web server. The file is a .txt file curretly less than 1 MB. Is it advisable to set up a ftp server to get the data or can i just use a http get method to get the contents on a file. If i am using a http get can someone please tell me the java code required for this operation.

This is out of my head (so an error could have sneaked in):
URL url = new URL("http://www.yourserver.com/some/path");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
try {
InputStream in = new BufferedInputStream(urlConnection.getInputStream());
FileOutputStream out = new FileutputStream("/path/to/your/output/file");
byte[] buffer = new byte[16384];
int len;
while((len = in.read(buffer)) != -1){
out.write(buffer, 0, len);
}
finally {
urlConnection.disconnect();
}