Android MediaPlayer Service NullPointerException
What is a NullPointerException, and how do I fix it?
I don't understand this..maybe there is something wrong with my understanding of battery or electricity.  I am learning about electricity more deeply this time. So please bear with me.  So lets begin with what I know:   follow of current occurs when there is voltage drop. voltage drop happens when there is imbalance in charge. a battery is basically two separated chemicals. One side with electrons to spare and other side that needs electron to balance itself. which is imbalance in charge. When both sides are connected + side snatches electrons from - side. (And if there is a medium, conductor, then first electrons are taken from conductor that in turn snatches from - side, which not being able to keep electrons lose them and give up those electrons, we label it as excessive.)   The analogy i was taught with used marbles in pipe... When one side has excessive marbles And this pipe is connected to other side that has no marbles the marbles will instantaneously start falling out so even though marbles from container with excessive marbles haven't traveled there yet, they still start falling because filled side marbles are pushing marbles in pipe and which in turn push the last marbles in pipe out.   1st, Aren't electrons pulled by atoms that can use more electrons, and not move because one side is overfilled with electrons so they can't wait to push some out.  Questions:    if I connect a conductor to positive side of a battery, shouldn't it make all electrons/marbles fall into empty container as empty container will pull marbles as atoms need electrons? if I connect two batteries' only opposite sides to each other shouldn't they drain (balance the each other out, cancelling all - &amp; + charges)? How to bond two different internet connections I have two internet connection, each with 4mbps bandwidth. I want to join/merge both of them to get 8mbps speed, both routers have WLAN and LAN capability.    How to Double my speed using two routers? Can I bond two connections in Windows and double my internet connection speed? Any download manager that accepts two internet connection to download? Java: Detect duplicates in ArrayList? How could I go about detecting (returning true/false) whether an ArrayList contains more than one of the same element in Java?  Many thanks, Terry  Edit Forgot to mention that I am not looking to compare "Blocks" with each other but their integer values. Each "block" has an int and this is what makes them different. I find the int of a particular Block by calling a method named "getNum" (e.g. table1[0][2].getNum(); How do I pre-populate a jQuery Datepicker textbox with today's date? Excel multiple FIND formula I am no expert with excel so any help is appreciated!   I am trying to make one cell do multiple searches within another.  I know that to search one cell for a specific word you would use  =FIND(Blue,C2)   But I need to find multiple different words in one cell. Heres an example of what im trying to do:    I need to show all the allergens in the ingredients cell eg peanuts, gluten, milk, sesame seeds etc   How do I get the result to list all the allergens?   I know that I can do a single find function in separate cells and then concatenate them, but there must be a more simple way?  Thanks What's the hardest or most misunderstood aspect of LINQ? In my past experiences, I have almost never typeset my manuscripts according to the formats required by the journals to which I would like to submit. I leave my manuscripts as produced by the LaTeX article documentclass.  Recently I am wondering: Would such a behavior generally give handling editors a negative first impression? What is the correct name for a "product function" on a monoid? I'm fairly certain this has happened to all of us at some point: You go into a room to get something, but once you're there, you can't remember what you intended to get. It seems like a specific, common phenomenon like this must have a name, but I can't think of it. Does anyone know a name (either formal or slang) for this?  I don't want a general term like forgetfulness or absent-mindedness, which could apply to all sorts of forgetting, or a term for not being able to remember a certain word. I'm looking for a word or phrase that describes this one specific situation of forgetting what you need to get as soon as you go to get it. When I sum up the sizes of my files, I get one figure. If I run du, I get another figure. If I run du on all the files on my partition, it doesn't match what df claims is used. Why are there so many different figures for the total size of my files? Can't computers add?  Speaking of adding: when I add the “Used” and “Available” columns of df, I don't get the total figure. And that total figure is smaller than the size of my partition. And if I add up my partition sizes I don't get my disk size! What gives? How to split strings into text and number? I'd like to split strings like these  'foofo21' 'bar432' 'foobar12345'   into  ['foofo', '21'] ['bar', '432'] ['foobar', '12345']   Does somebody know an easy and simple way to do this in python? How long does it take for reputation on Stack Overflow Careers to be updated? Just curious how this works:  My Stack Overflow reputation on my Stack Overflow CV shows an amount X, which is less than my actual Stack Overflow reputation Y. It's been this way for a few days. In addition, some of my 'favorite answers' on my CV have a lower # of votes than they do in reality.  How long does it take for this (I assume cached) value to be updated? Is there a way to display a player name in /tellraw command? like the title says, I'm looking for a way to display a player name in a /tellraw command which is run by a command block. Example:  /tellraw @a {"text":"","extra":[{"text":"A player has won the game!","color":"blue"}]}   And the output is something like this:  A player has won the game!   But I want the output to be something like  JasonSPQR has won the game!   Using the @p parameter I installed clang-format on Ubuntu 18.04 LTS with sudo apt install clang-format and the installation was successful. I can execute clang-format-6.0 now, but when I use ClangFormat in vim, it tells me that "clang-format is not found". How can I fix the problem? Title does not specify "On Hold" Testing the app, I noticed the title does not specify if a question is "On Hold" ... I haven't checked specifically, but would assume it doesn't specify as "Duplicate" either ... Or am I missing it somewhere? Is it not in the title but located/displayed some other way? If it is, this could be very confusing to users. If it isn't there, it's definitely confusing to users :-)  Using: Version 1.0.1.125 on iPad3 with iOS8 Adding Layer Files (.lyr, .lyrx) to QGIS At college we use ArcGIS Desktop 10, but that does not function on my Mac so I have QGIS there instead.  I want to do my exercises with QGIS, but in ArcGIS Desktop we use .lyr files with ArcMap and .lyrx files with ArcGIS Pro, and they are not supported by QGIS.  Does anyone know, how I can connect the *.lyr files to my *.shp files to use them on my Mac with QGIS? What's the Pythonic way to combine two sequences into a dictionary? Is there a more concise way of doing this in Python?:  def toDict(keys, values):   d = dict()   for k,v in zip(keys, values):     d[k] = v    return d Adding Basemaps from Google or Bing in QGIS I have a list of Line_item__c which is storing my line items as  List&lt;Line_Item__c&gt; toInsertList = new List&lt;Line_Item__c&gt;();   I am inserting these records in database using the below statement :  List&lt;Database.Saveresult&gt; insertResults=Database.insert(toInsertList, false);   Now the result is stored in insertResults which is of Database.Saveresult type but i want the result in a list of Line_Item__c. How do i do this. If anyone has a idea, it will be of great use. Missing files (basic sty files) when TEXINPUTS is set Below is my files tree:  .../Doc/Tex/book.tex .../Doc/Tex/images/im.jpg .../Doc/TexBase/myTemplate.sty .../Doc/TexBase/baseImages/logo.jpg   On Windows it was enough to set TEXINPUTS evironment variable with some paths and then I was able to compile with:  pdflatex Tex/book.tex   my document book.tex which uses package myTemplate.sty And now im trying to do teh same on Ubuntu 18.04. When i move all things to one folder (book.tex and myTemplate.sty and folder with images) then compilation is succesfull. But i would like to keep my foder structure as it is more clearly. So i tried to export TEXINPUTS:  export TEXTINPUTS=.:./TexBase/   but my compilation fail because of unfound many sty-files wchich are part of texlive-latex-extra that i already installed. When i UNSET this variable - it compiles ok. So my question is: Am i correctly set TEXINPUTS variable? Maybe i should add some other paths? What is the path to those "latex basic STY files"?