### IDEA概述和安装

#### IDEA概述

IDEA全称IntelliJ IDEA，是用于Java语言开发的集成环境，它是业界公认的目前用于Java程序开发最好的工具。

集成环境：把代码编写，编译，执行，调试等多种功能综合到一起的开发工具。

IDEA的下载和安装
下载：https://www.jetbrains.com/idea/
安装：傻瓜式安装，建议修改安装路径。

#### IDEA安装

**欢迎界面**

![](https://img.slcp.top/20200802111413254.png)

**选择安装路径**

![image-20200801085044603](https://img.slcp.top/image-20200801085044603.png)

`建议新建一个Develop文件夹,用来存放开发工具`

![image-20200801085110102](https://img.slcp.top/image-20200801085110102.png)

**配置安装选项**

![image-20200801085237002](https://img.slcp.top/image-20200801085237002.png)

**开始菜单**

![image-20200801085243994](https://img.slcp.top/image-20200801085243994.png)

**安装完毕**

![image-20200801085249697](https://img.slcp.top/image-20200801085249697.png)

### IDEA项目结构介绍

* project（项目、工程）
* module（模块）
* package（包）
* class（类）

#### IDEA项目结构

淘宝、京东、黑马程序员网站都属于一个个项目，IDEA中就是一个个的Project

* 层级关系

project - module - package - class

* 小结

project中可以创建多个module
  module中可以创建多个package
  package中可以创建多个class

这些结构的划分，是为了方便管理类文件的。

### IDEA编写HelloWorld

#### 操作步骤

1. 创建Project 项目
2. 创建Module 模块
3. 创建Package 包
4. 创建class   类
5. 在类中编写代码
6. 完成编译运行

`1.创建Project (项目)`

**选择** `Create New Project`

**选择左下角的** `Empty Project`

![image-20200801090517680](https://img.slcp.top/9.png)

**输入项目名称和保存路径**

![image-20200801090525742](https://img.slcp.top/10.png)

![image-20200801090533786](https://img.slcp.top/image-20200801090533786.png)

**打开一个每日一帖对话框，勾掉每次启动显示，点击** close

![](https://img.slcp.top/Snipaste_2020-08-01_09-37-55.png)

`2.创建Module (模块)`

**在弹出的窗口中，点击+号。选择**` new module`

![image-20200801090610105](https://img.slcp.top/image-20200801090610105.png)

![image-20200801090630623](https://img.slcp.top/image-20200801090630623.png)

**在弹出的new module窗口中，点击** `new`

![image-20200801090636091](https://img.slcp.top/image-20200801090636091.png)

**选择** jdk12 **目录 ，点击确定。再点击**` next`

![image-20200801090646089](https://img.slcp.top/image-20200801090646089.png)

![image-20200801090650255](https://img.slcp.top/image-20200801090650255.png)

**给视图起名字，然后点击** `finsh`

![image-20200801090654757](https://img.slcp.top/image-20200801090654757.png)

**创建完成后，点击** `ok`

![image-20200801090659319](https://img.slcp.top/image-20200801090659319.png)

`3. 创建Package (包)`

![image-20200801090719933](https://img.slcp.top/image-20200801090719933.png)

![image-20200801090725616](https://img.slcp.top/image-20200801090725616.png)

`4. 创建class (类)`

**展开创建的工程，在源代码目录** src **上，鼠标右键，选择** new**-**

\>package **，键入包名** `com.itheima.Demo1` **，点击确定。**

![image-20200801090744615](https://img.slcp.top/image-20200801090744615.png)

![image-20200801090750322](https://img.slcp.top/image-20200801090750322.png)

`5. 在类中编写代码`

![image-20200801090806790](https://img.slcp.top/image-20200801090806790.png)

`6. 编译运行代码`

> 注意：IDEA会自动完成编译，所以写好代码，直接运行即可

![image-20200801090838076](https://img.slcp.top/image-20200801090838076.png)

![image-20200801090903930](https://img.slcp.top/image-20200801090903930.png)

![image-20200801090908510](https://img.slcp.top/image-20200801090908510.png)

#### 设置字体

点击菜单栏上的` File->Settings->Editor->Font `修改字体

![image-20200801091006873](https://img.slcp.top/image-20200801091006873.png)

![image-20200801091022594](https://img.slcp.top/image-20200801091022594.png)

#### 设置背景

![背景](C:%5CUsers%5CDELL%5CDesktop%5C%E8%83%8C%E6%99%AF.png)

* Theme设置

![背景2](C:%5CUsers%5CDELL%5CDesktop%5C%E8%83%8C%E6%99%AF2.png)

* 背景图片设置

![背景3](C:%5CUsers%5CDELL%5CDesktop%5C%E8%83%8C%E6%99%AF3.png)

### IDEA常用快捷键

| 快捷键           | 作用                               |
| ---------------- | ---------------------------------- |
| psvm + Enter     | 快速生成main方法                   |
| sout + Enter     | 快速生成输出语句                   |
| Alt + 1          | 打开 \ 隐藏工程目录结构            |
| Alt + 4          | 打开 \ 隐藏控制台                  |
| Ctrl + D         | 向下复制一行                       |
| Ctrl + X         | 剪切当前行                         |
| Ctrl + A         | 全选                               |
| Ctrl + C         | 复制                               |
| Ctrl + V         | 粘贴                               |
| Ctrl + Alt + L   | 格式化代码                         |
| Alt+ Enter       | 代码修正提示                       |
| Ctrl + /         | 批量加入单行注释，再按一次就是取消 |
| Ctrl + shift + / | 批量加入多行注释，再按一次就是取消 |
| Alt + shift + ↑  | 上移当前行                         |
| Alt + shift + ↓  | 下移当前行                         |
| ...              | ...                                |

###  IDEA操作项目和模块

#### IDEA中操作模块

* 创建新模块
* 删除模块
* 导入

#### IDEA中创建新模块

![image-20200801092138292](https://img.slcp.top/image-20200801092138292.png)

![image-20200801092143359](https://img.slcp.top/image-20200801092143359.png)

![image-20200801092149373](https://img.slcp.top/image-20200801092149373.png)

![image-20200801092154776](https://img.slcp.top/image-20200801092154776.png)

![image-20200801092159428](https://img.slcp.top/image-20200801092159428.png)

#### IDEA中删除模块

![image-20200801092222115](https://img.slcp.top/image-20200801092222115.png)

![image-20200801092233020](https://img.slcp.top/image-20200801092233020.png)

#### IDEA中导入模块

![image-20200801092246922](https://img.slcp.top/image-20200801092246922.png)

![image-20200801092251931](https://img.slcp.top/image-20200801092251931.png)

![image-20200801092256240](https://img.slcp.top/image-20200801092256240.png)

![image-20200801092300813](https://img.slcp.top/image-20200801092300813.png)

![image-20200801092305729](https://img.slcp.top/image-20200801092305729.png)

![image-20200801092310601](https://img.slcp.top/image-20200801092310601.png)

![image-20200801092315010](https://img.slcp.top/image-20200801092315010.png)

![image-20200801092319930](https://img.slcp.top/image-20200801092319930.png)

![image-20200801092328644](https://img.slcp.top/image-20200801092328644.png)

![image-20200801092337541](https://img.slcp.top/image-20200801092337541.png)

`如果出现"Poject SDK is not defind",那么就代表没有JDK，按右边Setup SDK导入JDK即可。`

![image-20200801092342365](https://img.slcp.top/image-20200801092342365.png)

![image-20200801092349096](https://img.slcp.top/image-20200801092349096.png)

#### IDEA中操作项目

* 关闭项目
* 关闭IDEA中已经存在的项目，` File->Close Project `

![image-20200801092732838](https://img.slcp.top/image-20200801092732838.png)

`File->Close Project` 这时IDEA回到了刚启动界面，点击项目上的 X ，IDEA中就没有这个项目了

![image-20200801092738056](https://img.slcp.top/image-20200801092738056.png)

* 打开项目

![image-20200801092810328](https://img.slcp.top/image-20200801092810328.png)

* 修改类名和包名

![image-20200801092826873](https://img.slcp.top/image-20200801092826873.png)

![image-20200801092831441](https://img.slcp.top/image-20200801092831441.png)

IDEA开发工具

目录