First knowledge of Java

A collection of ordered commands written to allow a computer to perform certain operations or solve a problem.

Introduction to the Java technology platform
Java SE: Standard Edition
The Foundation and core of Java technology.
Primarily used to develop desktop applications.
Java EE: Enterprise Edition
Provides a complete solution for enterprise-class application development
Many websites are developed using Java EE technology
Java ME

Java JDK
JDK (Java Development Kit) is the Java Development Kit
JRE (Java runtime enviroment) is the Java Runtime Environment
JVM (Java Virtual machine), Java VM
Java SE API, is the Java System Core Class library (to be used, including the network, Io,gui, etc.)

jdk[(Development Tools)
JRE (Java SE API)
(JVM)
]

Java language Programming Considerations
A. Case sensitive
B. After each code is written, the following semicolon ends (";")
C. In code, the appearance of parentheses is generally paired. such as: {}

Knowledge points
1.Java Project directory Structure
SRC directory: Storing source code in project
JRE System Library:java jar package for runtime environment
2. Create a new source file
SRC directory, new selects class and generates Java source files
Running programs in 3.myeclipse
After you run the-run As->java application program in the code area, right-click, the output is displayed in the console console.

Notes for Java programs
Knowledge Points:
Comments in Java: single-line comment, multiline comment, document comment
Single-line Comment://comment content, mainly on a single line of code, or variables are explained.
Multiline Comment:/* Comment content */, you can annotate multiple lines of code at once.
Document Comments:/** Comments * *, describe classes (class), or describe the method, and annotate the content to produce API documentation information.

Java Coding Specification
The necessity of coding specification, basic rules, specialization.
1. Class names are decorated with public
2. Write only one statement in a row.
The use and location of 3.{}.
4. Indent the code.

First knowledge of Java