How to retrieve image from database and display in JSP via Servlet?
How to retrieve and display images from a database in a JSP page?
Create unique number from 2 numbers is there some way to create unique number from 2 positive integer numbers? Result must be unique even for these pairs: 2 and 30, 1 and 15, 4 and 60. In general, if I take 2 random numbers result must be unique(or with very high probability unique)  Thanks a lot  EDIT: calculation is for computer program,so computational complexity is important One click shutdown Ubuntu and load into alternative bootup This is Exercise 26 from Chapter V Algebraic Extensions in Lang's Algebra.  $F$ is finite normal extension over $k$ and $f(x)$ is irreducible in $k[x]$. If $f(x)=g(x)h(x)k(x) \in F[x]$ where $g(x),h(x)$ are monic irreducible factors in $F[x]$, I need to show that there exists an automorphism of $F$ which takes $g(x)$ to $h(x)$.  Any hints would be appreciated.  Sending one root to another is okay but how to do that for a collection of roots? When can I use a forward declaration? I am looking for the definition of when I am allowed to do forward declaration of a class in another class's header file:  Am I allowed to do it for a base class, for a class held as a member, for a class passed to member function by reference, etc. ? If I did  \setcounter{chapter}{-1} \chapter{Introduction}   then I get Chapter 0 Introduction. I just want the word Introduction, and I want it also in the contents when I use   \tableofcontents   How can I do that? Space of bounded continuous functions is complete How to use the keyboard to drag and drop? Solving infinite sums with primes. Let $p_n$ denote the $n$'th prime number.  How would one go about proving that infinite products like: $$\prod_{k=1}^\infty1 - \frac{1}{(p_k)^2} = \frac{6}{\pi^2}$$  or  $$\prod_{k=1}^\infty\frac{{p_k}^2}{{p_k}^2 - 1} = \frac{\pi^2}{6}$$ are correct?  Is there any way to prove it except by exhaustion? I just installed a new version of Ubuntu and I want to roll it back to the previous version.  How can I do that? Is that even possible? Variance of the distribution of difference scores Array versus List: When to use which? found a 1994 uncashed profit sharing retirement plan check I found an old un-cashed check dated 1994 for $487 from my Xerox Retirement plan with no expiration date. Can I still cash it? Can you have a class in a struct? This is a question of the book Linear Algebra of Kenneth Hoffman.  Describe explicitly all inner products on $\mathbb{R}$ and on $\mathbb{C}$.  I think that if $&lt;,&gt;$ is one inner product on $\mathbb{R}$ (or $\mathbb{C}$) then $&lt; ,&gt;=K[,]$, where $[,]$ is the standard inner product. Is that correct? Prove that if 51 positive integers between 1 and 100 are chosen, then one of them must divide another. Given $51$ integers $a_1, a_2, \ldots, a_{51}$ satisfying $1 \leq a_i \leq 100$. Prove that there exist $i$ and $j$ such that $a_i \mid a_j$.   I'm a little unsure how to approach this problem. Thanks for any help. Add warning when changing display name The policy on changing one's display name :  only one display name change is allowed every 30 days  However, there is no warning whatsoever when actually changing one's display name.  Thus, it came as quite a bit of a shock to me when I found out today that I might be stuck as &quot;Unicorns are Yummy&quot; on Stack Overflow for the next freakin' month. I would like to recommend that a warning be added to the &quot;Edit Profile&quot; page to warn people. Or, at least make the policy concerning display name changes more obvious. Workaround I was able to change my display name back (phew!) by copying my profile from Meta Stack Overflow. I still think a warning should be implemented, though. Significance of the second focus in elliptical orbits prove that : $\cos x \cdot \cos(x-60^{\circ}) \cdot \cos(x+60^{\circ})= \frac14 \cos3x$ I should prove this trigonometric identity. I think I should get to this point : $\cos(3x) = 4\cos^3 x - 3\cos x $ But I don't have any idea how to do it (I tried solving $\cos(x+60^{\circ})\cos(x-60^{\circ})$ but I got nothing) TeXstudio not large enough to use on a 4k display How to reset evolution settings to defaults? I have not used Evolution for long time now and I would like to reset all the settings and start from scratch. How would I be able to do this?