JAVA SE -01 basis Synopsis: Introduction and environmental structures

0x01.JAVA SE Overview

SUN JAVA language is American Company (Stanford University Network) in 1995 launched the high-level programming language, an object-oriented programming language.
JAVA Classification:
1: JAVA SE, also known as J2SE, JAVA standard version is mainly used for desktop applications programming software.
2: JAVA ME, it is a miniature version JAVA2 platform, mainly used in embedded systems development, such as set-top boxes, mobile phones and PDA's embedded consumer electronic devices.
3: JAVA EE, enterprise version JAVA2 platform, developers are mainly used in the distributed network programs, such as e-commerce sites and ERP systems.

Language characteristics 0X02.JAVA

Cross-platform:

JVM (Java Vitual Machine): Java virtual machine environment is directly run Java programs.
Written in Java software can run on different operating systems, such as windows system, linux system, mac system, this feature is implemented by the JVM, java program run on JVM, and JVM running on the operating system, developers made JVM under different operating systems, so Java program can run on different operating systems.

safety:

Java's security can be guaranteed in two ways. On the one hand, in the Java language, delete the pointer and release memory and other C ++ function, to avoid illegal memory operations. On the other hand, to ensure the security of Java code through the Java security architecture. When we download Java code is executed locally from the Internet, Java security architecture ensures that malicious code can not freely access our local computer resources, such as: deleting files, access to local network resources and other operations are prohibited.

Object-oriented:

Support inheritance, overloading, properties such as object-oriented polymorphism, Java language is completely object-oriented design.

0X03.JAVA build environment (IDEA)

JDK与JRM：

JRE (Java Runtime Environment): JAVA runtime environment is required contains the runtime libraries and core JVM.
JDK (Java Development Kit): Java is a development kit contains the tools needed when JRE and SDK.

IDEA installation and use:

IDEA stands for IntelliJ IDEA, a java programming language integrated development environment. IntelliJ in the industry is recognized as the best java development tools, especially in the intelligent code assist, code tips, reconstruction, J2EE support, various versions of tools (git, svn, etc.), JUnit, CVS integration, code analysis, innovations GUI design and other aspects of the function can be said to be exceptional.
Description: IDEA No official Chinese version is recommended to use the English original, not the Baidu.
Download: Click here to download
Once there click on IDEA, beginners can download the free community version.
IDEA main interface:
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common shortcuts:

Alt +`Enter`:导入包，自动修正代码
Alt +`Ins`:自动生成代码，适用于toString,get,set等
Alt +`光标上下行`：移动当前代码
Ctrl +`/`:单行注释
Ctrl +Shift+`/`:多行注释
Ctrl +`Y`:删除光标所在行
Ctrl +`D`:复制光标所在行代码，插入光标的下一行
Ctrl +Alt +`L`:格式化代码

IDEA modify keyboard shortcuts:
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Solutions to common problems:
console output Chinese garbled:
First of all encoding format unification as UTF-8.
Then the main interface Helpunder selection Edit Custom VM Options, the -Dfile.encoding=utf-8paste inside.
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Click Run to load can not find the main class:

IDEA Common convenient input:

输入psvm按回车会自动生成public static void main(String[] args)（带一对括号）
输入sout按回车会自动生成System.out.println();
输入100（值可变为变量）.fori按回车会自动生成for (int i = 0; i < 100; i++)（带一对括号）