Which i/o approach is better and why?

Question

can someone please explain which i/o approach is better for obtain the data from the InputStream and why? and consequences for reading streams that contain 2-byte characters?
thank you.
InputStream in = conn.openInputStream();
approach 1
byte[] byteData = new byte[(int)conn.getLength()];
in.read(byteData);
String rawdata = new String(byteData);
approach 2
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buf = new byte[128];
int t;
while( (t=in.read(buf)) != -1) {
baos.write(buf,0,t);
String rawdata = new String(baos.toByteArray());

Answer 1

First way will be best in terms of performance: you do all the reading procedure in one sentence, avoiding the chequing of the loop condition check and invoking less times the method read, and you too sabe the memory space required for the object baos you employ in the second approach.
In performance terms I would say second option saves CPU and memory, so it's better.
Abraham.