IDEA maven 构建Spring Boot 应用（一）

痛定思痛。 2024-04-17 05:54 109阅读 0赞

## 第一个Spring Boot 应用程序。 ##

这里使用的开发软件是`IntelliJ Idea`，和`Eclipse`差不太多，界面更炫酷，功能更强大；`Android Studio`就是基于`IntelliJ` 开发的，我之前使用过`Android Studio`，它俩界面几乎一样。

maven配置的中央仓库阿里云镜像 ,（此步骤不是必须，可跳过）

<mirrors>
 <mirror>
 <id>alimaven</id>
 <name>aliyun maven</name>
 <url>http://maven.aliyun.com/nexus/content/groups/public/</url>
 <mirrorOf>central</mirrorOf> 
 </mirror>
 </mirrors>

### 1.使用IDEA创建Spring Boot项目 ###

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 2][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 3][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 4][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 5][]

运行`SpirngbootdemoApplication`的main方法，就能开始运行

控制台输出：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 6][]

创建一个`HelloController`，位于`controller`包下

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 7][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 8][]

以下参考（[https://www.cnblogs.com/tanlei-sxs/p/9855071.html][https_www.cnblogs.com_tanlei-sxs_p_9855071.html]）

除了使用`.properties`格式的文件，还可以使用`.yml`格式的配置文件(推荐)，更加简便   
`application.yml`

![format_png][]

把原来的`application.properties`文件删除   
注意格式，空格不能少

### 获取配置文件中的属性值 ###

我们也可以在配置文件中，配置数据，在 Controller 中获取,比如：   
`application.yml`

![format_png 1][]

> HelloController 获取配置文件中的值

`HelloController.java`

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 4 5 6 7 8 9 10 11 </td> 
 <td> <code>@RestController</code> <code>public</code>&nbsp;<code>class</code>&nbsp;<code>HelloController { </code> &nbsp; <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>@Value</code><code>(</code><code>"${name}"</code><code>)</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>private</code>&nbsp;<code>String name;</code> &nbsp; <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>@RequestMapping</code><code>(value =&nbsp;</code><code>"/hello"</code>&nbsp;<code>,method = RequestMethod.GET)</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>public</code>&nbsp;<code>String getName(){ </code> <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code>&nbsp;<code>name;</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>}</code> <code>}</code> </td> 
 </tr> 
 </tbody> 
</table>

返回的为name的值

![format_png 2][]

配置文件中值配置方式的多样化  
配置文件的值可以是多个，也可以是组合，如：

application.yml

或者

application.yml

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 </td> 
 <td> <code>name: 小胖</code> <code>age:&nbsp;</code><code>22</code> <code>content:&nbsp;</code><code>"name: ${name},age: ${age}"</code> </td> 
 </tr> 
 </tbody> 
</table>

或者

application.yml

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 4 5 6 </td> 
 <td> <code>server:</code> <code>&nbsp;&nbsp;</code><code>port:&nbsp;</code><code>8081</code> <code>&nbsp;&nbsp;</code><code>context-path: /springboot</code> <code>person:</code> <code>&nbsp;&nbsp;</code><code>name: 小胖</code> <code>&nbsp;&nbsp;</code><code>age:&nbsp;</code><code>22</code> </td> 
 </tr> 
 </tbody> 
</table>

前两种配置获取值的方式都是一样的,但是对于这种方式，person 有相应的两个属性，需要这样处理

`PersonProperties.java`

package com.newer.springboot.dao;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.stereotype.Component;
 
 /**
 * @author:Mr.Tan
 * @Create:2018-10-26-17-07
 **/
 @Component//（把普通pojo实例化到spring容器中，相当于配置文件中的<bean id="" class=""/>）
 @ConfigurationProperties(prefix="person")
 public class PersonProperties {
 private String name;
 private Integer age;
 
 public String getName() {
 return name;
 }
 
 public void setName(String name) {
 this.name = name;
 }
 
 public Integer getAge() {
 return age;
 }
 
 public void setAge(Integer age) {
 this.age = age;
 }
 }

@Component//（把普通pojo实例化到spring容器中，相当于配置文件中的<bean id="" class=""/>）

> `Alt+insert`快捷键提示生成 `Getter and Setter`

`pom.xml`需要加入下面的依赖,处理警告

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 4 5 6 </td> 
 <td> <code>&lt;!--处理警告--&gt;</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>&lt;dependency&gt;</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>&lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>&lt;artifactId&gt;spring-boot-configuration-processor&lt;/artifactId&gt;</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>&lt;optional&gt;</code><code>true</code><code>&lt;/optional&gt;</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>&lt;/dependency&gt;</code> </td> 
 </tr> 
 </tbody> 
</table>

HelloController.java

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 4 5 6 7 8 9 10 11 12 13 </td> 
 <td> <code>@RestController</code> <code>public</code>&nbsp;<code>class</code>&nbsp;<code>HelloController { </code> &nbsp; <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>@Autowired</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>private</code>&nbsp;<code>PersonProperties personProperties;</code> &nbsp; &nbsp; <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>@RequestMapping</code><code>(value =&nbsp;</code><code>"/hello"</code><code>,method = RequestMethod.GET)</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>public</code>&nbsp;<code>String say(){ </code> <code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>return</code>&nbsp;<code>personProperties.getName()+personProperties.getAge();</code> <code>&nbsp;&nbsp;&nbsp;&nbsp;</code><code>}</code> &nbsp; <code>}</code> </td> 
 </tr> 
 </tbody> 
</table>

![format_png 3][]

### 关于配置文件`application.yml`的多套配置 ###

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 </td> 
 <td> <code>类似 il8n 文件国际化的配置方式i18n_en_US.properties和i18n_zh_CN.properties</code> <code>这样能解决，需要频繁修改配置的尴尬</code> </td> 
 </tr> 
 </tbody> 
</table>

![format_png 4][]

由`application.yml`配置文件决定使用那套配置文件。

**`application.yml`**

![format_png 5][]

**application-a.yml**

![format_png 6][]

** application-b.yml**

![format_png 7][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/11/21ffeab4cac04c679d5c2d715d979153.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/11/f7f32d1ed138484a8e14a54ec27f1d8f.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 2]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/11/0c14255540e14146957cc21764d0cfa4.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 3]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/11/558c6f385b72434384b5d97ee4ff9457.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 4]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/11/25a497d29c62499b82c646951454d54a.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 5]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/11/d8b223b88116428e98e795bfc8170a54.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 6]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/11/3900919d53ab46468853351f29280320.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 7]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/11/40942ae797bf4669b80edee86d05c7c2.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Jic3lp_size_16_color_FFFFFF_t_70 8]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/11/54455e3b52d942a18d5d70b1e9d49b41.png
[https_www.cnblogs.com_tanlei-sxs_p_9855071.html]: https://www.cnblogs.com/tanlei-sxs/p/9855071.html
[format_png]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pbWcyMDE4LmNuYmxvZ3MuY29tL2Jsb2cvMTQ2MDYwOC8yMDE4MTAvMTQ2MDYwOC0yMDE4MTAyNjE2NDcwNjA2OS0yMDYyNzg5NDA1LnBuZw?x-oss-process=image/format,png
[format_png 1]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pbWcyMDE4LmNuYmxvZ3MuY29tL2Jsb2cvMTQ2MDYwOC8yMDE4MTAvMTQ2MDYwOC0yMDE4MTAyNjE2NDc1NjczMi0xMTY3OTQ3NjkzLnBuZw?x-oss-process=image/format,png
[format_png 2]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pbWcyMDE4LmNuYmxvZ3MuY29tL2Jsb2cvMTQ2MDYwOC8yMDE4MTAvMTQ2MDYwOC0yMDE4MTAyNjE2NTIwNjIzMy0xNDc5NzE5MzA1LnBuZw?x-oss-process=image/format,png
[format_png 3]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pbWcyMDE4LmNuYmxvZ3MuY29tL2Jsb2cvMTQ2MDYwOC8yMDE4MTAvMTQ2MDYwOC0yMDE4MTAyNzAzNTczMDY5OC0xMDIwODMxMTIzLnBuZw?x-oss-process=image/format,png
[format_png 4]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pbWcyMDE4LmNuYmxvZ3MuY29tL2Jsb2cvMTQ2MDYwOC8yMDE4MTAvMTQ2MDYwOC0yMDE4MTAyNzAzNTg1MjkzOS0xMzA0OTYzNDIucG5n?x-oss-process=image/format,png
[format_png 5]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pbWcyMDE4LmNuYmxvZ3MuY29tL2Jsb2cvMTQ2MDYwOC8yMDE4MTAvMTQ2MDYwOC0yMDE4MTAyNzA0MDIyNDk4Ny0xMzExMTA3Njk3LnBuZw?x-oss-process=image/format,png
[format_png 6]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pbWcyMDE4LmNuYmxvZ3MuY29tL2Jsb2cvMTQ2MDYwOC8yMDE4MTAvMTQ2MDYwOC0yMDE4MTAyNzA0MDIwNjM3OS0xODk2MDE3MTM4LnBuZw?x-oss-process=image/format,png
[format_png 7]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pbWcyMDE4LmNuYmxvZ3MuY29tL2Jsb2cvMTQ2MDYwOC8yMDE4MTAvMTQ2MDYwOC0yMDE4MTAyNzA0MDMzMjAyOC0yODM0MTQ4NzEucG5n?x-oss-process=image/format,png