FileInputStream读取的文件不断返回0

Question

I am using FileInputStream to read a file on android phone. But when I used the FileInputStream.read to read data into array, the return value is always 0. I have checked that the path and file name is correct. Whats the possible reasons?

in = new FileInputStream(inFilename)
int readsize = 0;//Read size keep returning 0. 
do{
    readsize = in.read(data);
    Log.d(Constants.TAG, "Readsize:"+readsize);
    out.write(data);
} while(readsize > 0 );

Answer 1

This is only possible if you supplied a zero-length buffer, or a zero count in the case of the three-argument read.

NB The write line should be

out.write(data, 0, readsize);

and the loop should be written as

while ((readsize = in.read(data)) > 0)
{
    out.write(data, 0, readsize);
}

The way you have it, you're calling write() at end of stream, which isn't correct.

You don't need to initialize readsize either.