For copy one file to another one, just run next code:
InputStream inStream = null;
OutputStream outStream = null;
try{
File firstfile =new File("firstfile.png");
File secondfile =new File("secondfile.txt");
inStream = new FileInputStream(firstfile);
outStream = new FileOutputStream(secondfile);
byte[] buffer = new byte[1024];
int length;
while ((length = inStream.read(buffer)) > 0){
outStream.write(buffer, 0, length);
}
inStream.close();
outStream.close();
}catch(IOException e){
e.printStackTrace();
}