Java for AnyLogic

An introduction to the basic concepts we will be covering in this section

We will be covering the following concepts.

• Variables – What are they and how can you use them

• Functions - or as they are known in Java “Methods”

• The if-statement – How do you make things occur only under specific conditions

• The ternary operator (The little brother of the if-statement)

• The for loop – how do you make code execution iterative

What is an AnyLogic variable and how does it match its Java counterpart?

Aspects covered in this lecture:

• What is a variable?

• Creating Variables in AnyLogic

• Naming of variables

• AnyLogic Specific settings

• Data types

• Initial value

• Access

• Constant

• Java docs or descriptions

• Variables versus parameters

• Variable types

• Creating your own variables

At each section we will compare standard Java versus the setup in AnyLogic and use examples where applicable

How to use java functions, or methods as they are known in Java.

Aspects covered in this lecture:

• What is a function?

• Creating functions in AnyLogic

• Naming of functions

• AnyLogic Specific

• Return type

• Arguments

• Function body

• Access

• Java docs or descriptions

• Creating your own functions

• Overloading

• Behind the scenes

At each section we will compare standard Java versus the setup in AnyLogic and use examples where applicable

The most common, and essential, building blocks of any programming language... The If-Statement

An if statement is used to execute a block of code only if a specific condition is met.

A ternary operator is a special form of a single if statement

Aspects covered in this lecture:

• The If Statement

• Ternary operator

Some simple examples for each type

The student will learn how to repeat the same piece of logic by using a loop.

For loop is a special control statement that executes a block of code several times.

Preferred if the number of iterations is predefined or can be calculated

Aspects covered in this lecture:

• For each based loops

• Counter based loops

• How to exit a loop prematurely

• How to skip an iteration in a loop

Examples under each section

In this section we discuss Java objects that save a reference to multiple pieces of data in a structured format, also called collections.

• We will be covering the following concepts.

• Lists

• ArrayList

• LinkedList

• Sets

• HashSet

• LinkedHashSet

• TreeSet

• Maps

• HashMap

• LinkedHashMap

• TreeMap

There are examples where applicable

Learn how to efficiently store data in a more complex data structure.

Two main types of list we use:

• LinkedList: fast for adding and deleting elements, but slow to access a specific element.

• ArrayList: fast for accessing a specific element but can be slow to add to either end, and especially slow to delete in the middle

Aspects covered in this lecture:

• ArrayLists

• Sorting Lists

• Create your own list in function

• Some useful List functions

Examples under each section

Learn how to efficiently store unique data in a collection and how Set differs from Lists.

There are three main types of sets:

• HashSet: no order of the items and future order might change

• LinkedHashSet: An order based on the sequence of adding them

• TreeSet: Order based on some characteristics of the objects in the set

  
  

The main difference to lists:

• Can only contain one single reference to an object (No duplicates)

• Sets have no index, you can't access the objects by index.

• Very efficient in checking if an object exists within a set

Aspects covered in this lecture:

• LinkedHashSet

• Why we don’t use HashSet

• Key benefits of Set

• TreeSet

• Sorting sets

• Create your own set in function

Examples under each section

Lecture on how to properly store key/value pairs in a collection and how to use them efficiently in AnyLogic

Map is a unique collection of objects, stored as keys, but with corresponding values.

Two main types of maps we use in simulation models:

• LinkedHashMap: keys are ordered based on the sequence of adding them

• TreeMap: Keys are ordered based on some characteristics of the objects in the keyset

Similar to Sets there is an unordered version of Map, HashMap rarely used in simulation models since the order is not guaranteed.

Like Sets Maps have no index, you cant get the i’th element, but you can efficiently return a value for a given key

Aspects covered in this lecture:

• LinkedHashMap

• TreeMap

• Looping through a map and other useful functions

• Create your own map

Examples under each section

Why use a while loop when you have for loops? Learn why with this lecture.

Two loop types, While and Do While

Loops can be dangerous, if conditions are not set properly loops becomes infinite, causing your model to freeze

Aspects covered in this lecture:

• while loop

• do while loop

• How to prematurely exit a loop

Examples under each section

A more user-friendly if statement. Learn how to take advantage of the switch statement.

Switch is a special conditional, control statement

Aspects covered in this lecture:

• switch statement

• Using switch with Option Lists (enumerators)

• “if” vs “switch”

Examples under each section

Here we learn how to use a fundamental part of Object-Oriented Programming, classes. How to create classes and how do these compare to Agents in Anylogic

Aspects covered in this lecture:

• Creating a Java Class in AnyLogic

• Fields (Variables)

• Constructors

• Methods (Functions)

• Converting a Java class into an Agent

• Classes vs Agents

Examples under each section

How to make your models extendable by using class inheritance. What are the benefits and pitfalls?

Inheritance = where one object inherits all the properties of another

An important aspect of Object Orientated programming

Great for reusing code and sharing between multiple objects, allows for better organization and management of code

Aspects covered in this lecture:

• Inheritance in AnyLogic

• Inheritance in Java Class

• Overriding a method

• Polymorphism and casting

Examples under each section

Here the student learns about a special class, the Java Interface, and how it will improve the model development speed through the power of abstraction.

Interface = a set of abstract methods (methods without a body) and final or static variables

Aspects covered in this lecture:

• Interfaces in AnyLogic

• Default methods

• Interfaces in Java Class

• Polymorphism and casting

Examples under each section

In any simulation model, the ability to efficiently compare different objects/agents is a must. We often use this when prioritizing agents or within certain algorithms. This lecture teaches how to do this efficiently.

Objects in Java can be compared to each other through standard interfaces

Aspects covered in this lecture:

• Implementing Comparable in agents

• Creating a Comparator

Examples under each section

Learn about Java Enumerators, why they are important and how to use them in AnyLogic. Learn also some neat tricks to make your modeling experience more pleasant and bug-free.

Option List in AnyLogic = Enum Class in Java

List of a fixed set of constant values

Aspects covered in this lecture:

• Why do we use predefined lists

• Using option list

• Using Enum class

Examples under each section

Use access levels modifiers to your and your team's advantage by better structuring your code.

Aspects covered in this lecture:

• Example of access level

Why do we have multiple ways of checking if object A is the same as object B? When to use == or the method equals()?

Aspects covered in this lecture:

• Example of testing different data types

• Why String is such a special non-primitive type