NullPointerException when reading a properties file in Java
What is a NullPointerException, and how do I fix it?
Make 15 lines / ticks with Photoshop, each of them rotated of 20° I upgraded my Nexus 4 to Lollipop a few days ago but I don't like it. I'll leave out my reasons because they're not relevant here. I wiped my phone and installed a clean stock 4.2.2 version instead. I'm happy with this.  Not long after, Android automatically downloaded the 4.3 upgrade and notifies me with the choices "Later" and "Install". I don't want to do this upgrade.  How do I:   get rid of the notification, and  remove the downloaded update (to free up precious storage space).     I have already tried choosing "Later" but the same notification immediately reappears.    Based on Google search results, I also tried going to Settings &gt; Apps &gt; All &gt; Google Services Framework and unticked "show notifications" but it still appears. Force stop or disable also doesn't seem to help, so I've re-enabled the service including notifications. I didn't see any other apps in this list that sounded relevant - did I just not see it? How can I change wallpaper automatically? I have found a guide for that but doesn't sure if it will work or it is safe to use. The guide:  I am asking if is these introductions safe and will work? If not, is there any other solutions for that? I am using Ubuntu 20.04 LTS Thank you. Prove $\int_0^\infty \frac{\sin^4x}{x^4}dx = \frac{\pi}{3}$ I need to show that  $$ \int_0^\infty \frac{\sin^4x}{x^4}dx = \frac{\pi}{3} $$  I have already derived the result $\int_0^\infty \frac{\sin^2x}{x^2} = \frac{\pi}{2}$ using complex analysis, a result which I am supposed to start from.  Using a change of variable $ x \mapsto 2x $ :  $$ \int_0^\infty \frac{\sin^2(2x)}{x^2}dx = \pi $$  Now using the identity $\sin^2(2x) = 4\sin^2x - 4\sin^4x $, we obtain  $$ \int_0^\infty \frac{\sin^2x - \sin^4x}{x^2}dx = \frac{\pi}{4} $$ $$ \frac{\pi}{2} - \int_0^\infty \frac{\sin^4x}{x^2}dx = \frac{\pi}{4} $$ $$ \int_0^\infty \frac{\sin^4x}{x^2}dx = \frac{\pi}{4} $$  But I am now at a loss as to how to make $x^4$ appear at the denominator.  Any ideas appreciated.  Important: I must start from $ \int_0^\infty \frac{\sin^2x}{x^2}dx $, and use the change of variable and identity mentioned above What did Hisoka do in the Hunter Exam? In the first Hunter Exam of the series (Hisoka's second),  was introduced into the series removing another applicant's arms from his body for bumping into him and not apologizing.    What did he actually do? We know Hisoka's abilities are Bungee Gum and Texture Surprise, but they don't explain how the arms are converting into flower petals as seen above. How to compute the marginal likelihood given two multivariate Normal distribution? Given that $a$~$\mathcal{N}(\mu, \Sigma)$ and $\mu$~$\mathcal{N}(0, \sigma^2 I)$, Is $p(a|\Sigma, \sigma)=\int p(a|\mu, \Sigma)p(\mu|\sigma)d\mu$ again a Normal distribution? And how to estimate the mean and variance respectively? Thanks a lot! Oftentimes, I want to include code samples in a list, for example:   Item One Item Two, for example: private bool ItemTwo() {     return this.IFeelLucky; } Item Three   The problem is that there isn't a good and intuitive way to do this using . It's doable, but you have to do some formatting black-magic to get it that way, which is just not "nice" to deal with.  Source that produces this:  1. Item One 2. Item Two, for example: &lt;br/>&lt;br/>&lt;pre>&lt;code>private bool ItemTwo()     {         return this.IFeelLucky;     }&lt;/code>&lt;/pre> 3. Item Three    I would love to just be able to do it this way:  1. Item One 2. Item Two, for example:      private bool Test()     {         return this.IFeelLucky;     }  3. Item Three  Which results in, well, this:   Item One Item Two, for example:  private bool Test() {     return this.IFeelLucky; } Item Three Visa for European countries for US passport holder I'm a US passport holder. What documents do I need when I fly from the U.S. to Germany?  Assume I'm going for a few weeks of vacation.  Obviously I need my passport.  What about a "visa"?  Anything else? Why does a minimal prime ideal consist of zerodivisors? Let $A$ be a commutative ring. Suppose $P \subset A$ is a minimal prime ideal. Then it is a theorem that $P$ consists of zero-divisors.  This can be proved using localization, when $A$ is noetherian: $A_P$ is local artinian, so every element of $PA_P$ is nilpotent.  Hence every element of $P$ is a zero-divisor. (As Matt E has observed, when $A$ is nonnoetherian, one can still use a similar argument: $PA_P$ is the only prime in $A_P$, hence is the radical of $A_P$ by elementary commutative algebra.)  Can this be proved without using localization? How do I enable automatic updates? Sass Interpolation of Mixin, Function, and Variable names Make an object invisible to a specific camera? (Cycles) I'm trying to set up multiple cameras for a scene set in a room. Is there a way to link object visibility to a specific camera? Ideally, a wall or ceiling would not render if it were in the way of the specified camera.  I've tried to get around this by keyframing Restrict Rendering, but that gets difficult to keep track of. I've also tried adjusting the clipping plane, but that clips too much and would also need to be keyframed if the camera moves.   Thanks! OSX Server: should I use Open Directory? What does InitializeComponent() do, and how does it work in WPF? What does InitializeComponent() do, and how does it work in WPF?  In general first, but I would especially be interested to know the gory details of order of construction, and what happens when there are Attached Properties. Use the values of \title, \author and \date on a custom title page I am trying to create a title page of my own.  Is there a way to make use of the \title, \author and \date commands inside the title page?  For instance:  ... \title{Something Cool} \author{Cool Dude} \date{\today}  \begin{document} \begin{titlepage}  The title is \title It was written by \author on \date  \end{titlepage} \end{document}   Basically I just want to know if there is a way to leverage the information stored in \title, \author and \date inside the title page. I have been denied a visa several times in a row. How does one deal with such serial refusals? If $0 &lt; \alpha &lt; 1$, then       $$ (x + y)^{\alpha} &lt; x^{\alpha} + y^{\alpha} $$      for $x$, $y$ positive.   Is this inequality true in general?  I tried using Young's Inequality: For $z,t &gt; 0$, and for $n$, $m$ such that $n+m=1$, then   $$ z^n + t^m \leq nz + mt $$  So, using this we have   $$ (x+y)^{\alpha} \cdot 1^{1 - \alpha} \leq \alpha(x+y) + (1-\alpha) = \alpha x + \alpha y + (1-\alpha)$$  which is not as tight as I want. I am looking for a package to create bullet gauge graphs, but I couldn't find any.  A bullet graph looks like this:    and an ample description/specification can be found   It is available in Mathematica 9 ()  Is it possible create this kind of graphs in a easy way with TeX (like Matehmatica 9 or similar)? Returning from Dual-boot to just Windows I installed Ubuntu sometime back along side Vista, but later found that I rarely (if ever) use Ubuntu. How easy is it to return my computer to its initial state of having only one OS, and freeing up the hard-drive space used by the Ubuntu install? What’s the rule for using “who” and “whom” correctly? I can never figure out whether I should use who and whom. Most people use who for both colloquially, but some people say this is not correct.  What’s the rule for using who and whom correctly?