Java stack overflow error - how to increase the stack size in Eclipse?

It may be curable by increasing the stack size - but a better solution would be to work out how to avoid recursing so much. A recursive solution can always be converted to an iterative solution - which will make your code scale to larger inputs much more cleanly. Otherwise you'll really be guessing at how much stack to provide, which may not even be obvious from the input.

Are you absolutely sure it's failing due to the size of the input rather than a bug in the code, by the way? Just how deep is this recursion?

EDIT: Okay, having seen the update, I would personally try to rewrite it to avoid using recursion. Generally having a Stack<T> of "things still do to" is a good starting point to remove recursion.

Add the flag -Xss1024k in the VM Arguments.

You can also increase stack size in mb by using -Xss1m for example .

Open the Run Configuration for your application (Run/Run Configurations..., then look for the applications entry in 'Java application').

The arguments tab has a text box Vm arguments, enter -Xss1m (or a bigger parameter for the maximum stack size). The default value is 512 kByte (SUN JDK 1.5 - don't know if it varies between vendors and versions).