Java7 exception flow analysis

CallException.java

public class CallException
        implements Callable<Boolean>
{
    @Override
    public Boolean call()
            throws IOException
    {
        try {
            if (Math.random() > 0) {
                throw new IOException("random io failure");
            }
        }
        catch (Throwable e) {
            e.printStackTrace();
            throw e;
        }
        return true;
    }
}