Java
/
Basics
- 1 Basics 9
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Classes S
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Objects S
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Arrays S
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Variables S
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Loops S
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Numbers S
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Strings S
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Exceptions S
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Regexp S
- 2 OOP 9
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Inheritance
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Polymorphism
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Static S
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Abstract
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Interfaces
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Constructors S
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Packages
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Nested Classes
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Final
- 3 Compiler 2
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Sublime Text S
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Apache Ant
- 4 Collections 8
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Lists
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Comparable S
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Sets
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Maps
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Generics
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Properties
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Streams
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Json
- 5 Threads 4
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Create Thread S
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Sleep
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Lock
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Scheduler
- 6 Design Patterns 4
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Singleton
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Observer
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Strategy
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Mediator
- 7 Swing 12
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Frame
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Panel
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Listener
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Combo Box
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Label
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Image
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Menu
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Table
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Layout
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Drawing
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Timer
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Designer
- 8 I/O 7
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Streams IO
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Socket
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Watching Files
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Mail
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Logger
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Clipboard
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Encrypt S
- 9 Effective 7
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Constructors S
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Dependency Injection
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Composition
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Interfaces Default
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Import Static S
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Enums
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Lambdas
- 10 Junit 5
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About Junit S
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Test Case
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Suite Test
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Annotations
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Exceptions
- 11 Lambdas 7
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Expressions S
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Functional Interfaces
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Streams
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Common Operations
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Default Methods
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Static Methods S
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Single Responsibility
- 12 JavaFX 6
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Openjfx
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Scene Builder
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First App
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Jar Archive
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On Action
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Change Listener
- 13 Maven 4
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Demo
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Spring Boot
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Junit
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Guava
- 14 Spring Boot 13
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Quick start S
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Rest service S
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Consuming rest S
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Templates S
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Security auth S
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Command line S
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Scheduled task S
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Ajax S
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Jdbc mysql S
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Encrypt password S
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Https S
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Jwt S
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Post request S
S
R
Q
Java Basics Classes
In Java, everything goes into a class (.java file) A class is a blueprint for an object public class MyClass public static void main(String[] args)Hello
File
p9 In Java, everything goes into a class, into a file with .java extension.
/**
* In Java, everything goes into a class (.java file)
* JVM compiles the file, a .class file is created
*
* The program starts in main()
* The return type void means there is no returned value
* Every statement must end in semicolon
*/
package com.minte9.basics.classes;
public class Classes {
public static void main( String[] args ) {
System.out.println("Hello World!"); // Hello World!
}
}
Blueprint
p35 A class is a blueprint for an object.
/**
* A class is a blueprint for an object
*
* Instance variables (fields) is what an object knows
* Methods is what an object does
*/
package com.minte9.basics.classes;
public class Blueprint {
public static void main(String[] args) {
MyClass obj = new MyClass();
obj.setName("John");
System.out.println("Hello " + obj.name); // Hello John
}
}
class MyClass {
public String name;
public void setName(String name) {
this.name = name;
}
}
➥ Questions