File Download results with corrupted file. End of File problem

Question

Hello
I am tring to make a download program. I am tring to download an exe file from internet. Lets say the file in this website
http://www.oldversion.com/download/winrar154.exe
The part that helps me downloading is here, which is encapsulated with a "while" statement at an upper layer. So that code is a loop
                             byte buffer[];
                             if (size - downloaded > MAX_BUFFER_SIZE) {
                                 buffer = new byte[MAX_BUFFER_SIZE];
                             } else {
                                 buffer = new byte[size - downloaded];
                             // Read from server into buffer.
                             int read = inFromServer.read(buffer);
                             if (read == -1)
                                 break;
                             // Writing buffer to file below that partBut when there is no bytes left to download, it doesn't understand that end of file reached. The inFromServer.read method must return -1 whenever it reaches to an end of file, but in my code it continues looping within my "while" statement because it doesn't understand end of file has came, read becames 0 after there is no bytes left to download. It doesn't see that end of file is reached. And when download ends, the exe that I made is not working. By the way since this is my homework I am restricted to use many java classes like starts with http or url, so you don't need to suggest them. Here is my debug results for my integer read in the code: 1024 1024 1024 ....................... 512 0 0 0 0 0 ......, So till the end of the file it continues as 1024 which is my default buffer size, and at the end it continues as 0.
I would be happy if you help me.

Answer 1

There's a terrible amount of rubbish in this thread.
while(myStream.read(buffer) != -1){ //this will give the pretest you need for the eof.
//your stuff.
} This is rubbish because the return value isn't stored, so you don't know how much data was returned if EOS didn't occur.
If you're getting reads of length 0... you must have a bug in your code. read() methods do not return zero except via NIO in non-blocking mode.
if you get 10 0's in a rowYou can't even get one 0 in a row, see above.
int read = inFromServer.read(buffer);
if (read == 0)And again. This cannot occur.
The correct way to download a file, or indeed copy any input stream, is as follows:
int count;
byte[] buffe r= new byte[8192]; // or more
while ((count = in.read(buffer)) > 0)
  out.write(buffer, 0, count);
out.close();
in.close();