How do I peek at the first two bytes in an InputStream?

java inputstream bufferedinputstream
Epaga picture Epaga · Sep 29, 2008 · Viewed 19.2k times · Source

Should be pretty simple: I have an InputStream where I want to peek at (not read) the first two bytes, i.e. I want the "current position" of the InputStream to stil be at 0 after my peeking. What is the best and safest way to do this?

Answer - As I had suspected, the solution was to wrap it in a BufferedInputStream which offers markability. Thanks Rasmus.

Answer

Rasmus Faber picture Rasmus Faber · Sep 29, 2008

For a general InputStream, I would wrap it in a BufferedInputStream and do something like this:

BufferedInputStream bis = new BufferedInputStream(inputStream);
bis.mark(2);
int byte1 = bis.read();
int byte2 = bis.read();
bis.reset();
// note: you must continue using the BufferedInputStream instead of the inputStream

Related questions

How to read all of Inputstream in Server Socket JAVA

I am using Java.net at one of my project. and I wrote a App Server that gets inputStream from a client. But some times my (buffered)InputStream can not get all of OutputStream that client sent to my server. …

Read More
Adding characters to beginning and end of InputStream in Java

I have an InputStream which I need to add characters to the beginning and end of, and should end up with another variable of type InputStream. How could I easily do this?

Read More
How to clone an inputstream in java in minimal time

Can someone tell me how to clone an inputstream, taking as little creation time as possible? I need to clone an inputstream multiple times for multiple methods to process the IS. I've tried three ways and things don't work for …

Read More