Why are you using Streams rather than Readers? Are you dealing with text files? Readers work better than Streams for text files.
Why have you got a 1000-member array? You don’t need to keep those Strings in memory if you are simply writing them to a file. What you want is a writing method; you can read the line and write it to the other file in byte[] format from inside the same loop.
You can get rid of the break, which I consider awkward, like this
Why have you got the
char for the linefeed character? You appear not to use it. Why did you call it str1?
Why are you not closing your streams? You ought to close them in a
finally, or use
try-with-resources, which only works in Java7.
If you are simply writing the String as a
byte[], you are not adding line-end characters, so you will get the output as one continuous line.