\documentclass[10pt,a4paper]{article}

% Packages
\usepackage{fancyhdr}           % For header and footer
\usepackage{multicol}           % Allows multicols in tables
\usepackage{tabularx}           % Intelligent column widths
\usepackage{tabulary}           % Used in header and footer
\usepackage{hhline}             % Border under tables
\usepackage{graphicx}           % For images
\usepackage{xcolor}             % For hex colours
%\usepackage[utf8x]{inputenc}    % For unicode character support
\usepackage[T1]{fontenc}        % Without this we get weird character replacements
\usepackage{colortbl}           % For coloured tables
\usepackage{setspace}           % For line height
\usepackage{lastpage}           % Needed for total page number
\usepackage{seqsplit}           % Splits long words.
%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
\usepackage[normalem]{ulem}     % For underlining links
% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
\usepackage{amsmath}            % Symbols
\usepackage{MnSymbol}           % Symbols
\usepackage{wasysym}            % Symbols
%\usepackage[english,german,french,spanish,italian]{babel}              % Languages

% Document Info
\author{CommanderJak}
\pdfinfo{
  /Title (java.pdf)
  /Creator (Cheatography)
  /Author (CommanderJak)
  /Subject (Java Cheat Sheet)
}

% Lengths and widths
\addtolength{\textwidth}{6cm}
\addtolength{\textheight}{-1cm}
\addtolength{\hoffset}{-3cm}
\addtolength{\voffset}{-2cm}
\setlength{\tabcolsep}{0.2cm} % Space between columns
\setlength{\headsep}{-12pt} % Reduce space between header and content
\setlength{\headheight}{85pt} % If less, LaTeX automatically increases it
\renewcommand{\footrulewidth}{0pt} % Remove footer line
\renewcommand{\headrulewidth}{0pt} % Remove header line
\renewcommand{\seqinsert}{\ifmmode\allowbreak\else\-\fi} % Hyphens in seqsplit
% This two commands together give roughly
% the right line height in the tables
\renewcommand{\arraystretch}{1.3}
\onehalfspacing

% Commands
\newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour
\newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols
\newcolumntype{x}[1]{>{\raggedright}p{#1}} % New column types for ragged-right paragraph columns
\newcommand{\tn}{\tabularnewline} % Required as custom column type in use

% Font and Colours
\definecolor{HeadBackground}{HTML}{333333}
\definecolor{FootBackground}{HTML}{666666}
\definecolor{TextColor}{HTML}{333333}
\definecolor{DarkBackground}{HTML}{A30000}
\definecolor{LightBackground}{HTML}{FCF7F7}
\renewcommand{\familydefault}{\sfdefault}
\color{TextColor}

% Header and Footer
\pagestyle{fancy}
\fancyhead{} % Set header to blank
\fancyfoot{} % Set footer to blank
\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
    \SetRowColor{DarkBackground}
    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
    }
\end{tabulary}
\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Java Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{CommanderJak} via \textcolor{DarkBackground}{\uline{cheatography.com/121316/cs/22168/}}}
\end{tabulary}
\end{multicols}}

\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}CommanderJak \\
  \uline{cheatography.com/commanderjak} \\
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 26th March, 2020.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
  \SetRowColor{white}
  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

% Set font size to small. Switch to any value
% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.

\begin{multicols*}{3}

\begin{tabularx}{5.377cm}{x{2.68758 cm} x{2.28942 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Primitives - raw data types}}  \tn
% Row 0
\SetRowColor{LightBackground}
int (32-bits) & short (16) \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
float (32) & double (64) \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
char (16) & long (64) \tn 
% Row Count 3 (+ 1)
% Row 3
\SetRowColor{white}
byte (8) & boolean (1) \tn 
% Row Count 4 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{5.377cm}}{Wrapper Class - object version of primitive, can convert by un/autoboxing \newline Literal - represents a primitive value (d, f, ' ', " ", L)}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{2.4885 cm} x{2.4885 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Strings - immutable, final sequence of chars}}  \tn
% Row 0
\SetRowColor{LightBackground}
String Pool & area in Heap that stores String literals to save memory \tn 
% Row Count 3 (+ 3)
% Row 1
\SetRowColor{white}
`String s1 = "hi";\{\{nl\}\}String s2 =  "hi";\{\{nl\}\}String s3 = {\bf{new}} String ("hi");` & draws from same memory address\{\{nl\}\} \{\{nl\}\}stored in heap not pool \tn 
% Row Count 8 (+ 5)
% Row 2
\SetRowColor{LightBackground}
StringBuilder & mutable \tn 
% Row Count 9 (+ 1)
% Row 3
\SetRowColor{white}
StringBuffer & +threadsafe \tn 
% Row Count 10 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{5.377cm}}{Integer Pool - range -128 to 127}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Array - object holding elements of one type}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{`int{[}{]} numbers = \{1, 2, 3\};`} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{`int{[}{]} numbers = new int{[}size{]};`} \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{`int{[}{]}{[}{]} 2dArray = new int{[}rows{]}{[}columns{]}`} \tn 
% Row Count 3 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{1.59264 cm} x{3.38436 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Object Class - everything inherits from}}  \tn
% Row 0
\SetRowColor{LightBackground}
\seqsplit{`.toString();`} & prints memory address \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\seqsplit{`.equals();`} & checks for same memory address \tn 
% Row Count 4 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\seqsplit{`.hashCode();`} & id not guaranteed to be unique \tn 
% Row Count 6 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{5.377cm}}{Object - an instance of a class \newline Class - blueprint for object}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{1.4931 cm} x{3.4839 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Exceptions/Errors}}  \tn
% Row 0
\SetRowColor{LightBackground}
Error & cannot recover from\{\{nl\}\}stackoverflow, syntax... \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\seqsplit{Checked/Compile} & cannot compile, compiler sees\{\{nl\}\}FiloIO, SQLException... \tn 
% Row Count 5 (+ 3)
% Row 2
\SetRowColor{LightBackground}
\seqsplit{Unchecked/Runtime} & not required to be handled\{\{nl\}\}NullPointer, Arithmetic... \tn 
% Row Count 8 (+ 3)
% Row 3
\SetRowColor{white}
`throws` & throws e to method caller \tn 
% Row Count 9 (+ 1)
% Row 4
\SetRowColor{LightBackground}
`throw` & commands e be thrown\{\{nl\}\}useful for testing\{\{nl\}\}`throw new {\emph{ExceptionType}}();` \tn 
% Row Count 12 (+ 3)
% Row 5
\SetRowColor{white}
Create Exception & by extending `Exception` class\{\{nl\}\}`public Money Exception\{\{\{nl\}\}super("Error Message")\};` \tn 
% Row Count 16 (+ 4)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{5.377cm}}{`try\{{\emph{must have try \& catch/finally not just try}}\}` \newline `catch({\emph{ExceptionType}} e)\{{\emph{catches+ but only 1 runs}}\}` \newline `finally\{{\emph{always executes}}\};` \newline {\emph{Catches go from specific exception to general}}}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{1.34379 cm} x{3.63321 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Advanced Operators}}  \tn
% Row 0
\SetRowColor{LightBackground}
+ \seqsplit{Concatenation} & only operator overloading in Java \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\% Modulus & returns reminder (7 \% 5 = 2) \tn 
% Row Count 3 (+ 1)
% Row 2
\SetRowColor{LightBackground}
! Not & returns opposite boolean \tn 
% Row Count 4 (+ 1)
% Row 3
\SetRowColor{white}
++/-{}- Increment & pre (`println(++5)`=6)\{\{nl\}\}post (`println(5++)`=5) \tn 
% Row Count 6 (+ 2)
% Row 4
\SetRowColor{LightBackground}
\&\&/|| And/Or & short-circuit evaluates {\bf{one}} side \tn 
% Row Count 8 (+ 2)
% Row 5
\SetRowColor{white}
\& / | And/Or & evaluates {\bf{both}} sides \tn 
% Row Count 10 (+ 2)
% Row 6
\SetRowColor{LightBackground}
\textasciicircum{} Exclusive Or & both cannot be true \tn 
% Row Count 12 (+ 2)
% Row 7
\SetRowColor{white}
? Ternary & (if condition)? return:else return \tn 
% Row Count 14 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{2.28942 cm} x{2.68758 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Access Modifiers}}  \tn
% Row 0
\SetRowColor{LightBackground}
`Public` & all \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
`Private` & only class \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
`Protected` & also children \tn 
% Row Count 3 (+ 1)
% Row 3
\SetRowColor{white}
(Default) & only package \tn 
% Row Count 4 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{p{2.14011 cm} x{2.83689 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Scopes - where does reference extend}}  \tn
% Row 0
\SetRowColor{LightBackground}
Class & static \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
Object & instance \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
Method & local \tn 
% Row Count 3 (+ 1)
% Row 3
\SetRowColor{white}
Block & local \tn 
% Row Count 4 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{5.377cm}}{`Static \{{\emph{block runs at beginning when class first accessed, initialization}}\};`}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{2.83689 cm} x{2.14011 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{File I/O - data access outside JRE}}  \tn
% Row 0
\SetRowColor{LightBackground}
FileInput/OutputSteam & read/write bytes \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
FileReader/Writer & by characters \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
BufferedReader/Writer & line by line \tn 
% Row Count 3 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{5.377cm}}{`BufferedWriter bw = new BufferedWriter (new \seqsplit{FileWriter(".../java/src/main/resources.io.text"));`}}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{1.44333 cm} x{3.53367 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{`final` Keyword}}  \tn
% Row 0
\SetRowColor{LightBackground}
Class & cannot be extended \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
Method & cannot be overridden \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
Variable & cannot change value \tn 
% Row Count 3 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{1.29402 cm} x{3.68298 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Terms}}  \tn
% Row 0
\SetRowColor{LightBackground}
Java & classed-based object-oriented programming (OOP), write once run anywhere (WORA), automatic memory management, pass by value or copy reference, strong types \tn 
% Row Count 6 (+ 6)
% Row 1
\SetRowColor{white}
IDE & Integrated Development Environment \tn 
% Row Count 8 (+ 2)
% Row 2
\SetRowColor{LightBackground}
Linter & auto compiles and catches errors in IDE \tn 
% Row Count 10 (+ 2)
% Row 3
\SetRowColor{white}
\seqsplit{Reflection} API & allows java to write code at runtime where classes, fields, methods are treated as objects \tn 
% Row Count 14 (+ 4)
% Row 4
\SetRowColor{LightBackground}
Recursion & calling a method within itself \tn 
% Row Count 16 (+ 2)
% Row 5
\SetRowColor{white}
Code Coverage & how much reachable tested code \tn 
% Row Count 18 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{1.19448 cm} x{3.78252 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Memory}}  \tn
% Row 0
\SetRowColor{LightBackground}
\seqsplit{MetaSpace} & unchanging info \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\seqsplit{HeapSpace} & variable content \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\seqsplit{StackSpace} & method calls/variable references \tn 
% Row Count 4 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}