目录
Spring Boot
作用（使用 Spring Boot 的目的）
基于 约定优于配置 的思想，省略了大量的配置（Spring Framework 会使用大量 xml 配置，且很多重复的）
开发步骤
- 创建普通 maven 项目
写入 pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<!-- 默认使用的Spring Framework版本为5.2.10.RELEASE -->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>org.example</groupId>
<artifactId>springboot-study</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!-- spring-boot-starter-web: 基于SpringBoot开发的依赖包，
会再次依赖spring-framework中基本依赖包，aop相关依赖包，web相关依赖包，
还会引入其他如json，tomcat，validation等依赖 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<!-- 排除tomcat依赖 -->
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- 添加 Undertow 依赖 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-undertow</artifactId>
</dependency>
<!--引入AOP依赖-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<!-- spring-boot-devtools: SpringBoot的热部署依赖包 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<!-- 不能被其它模块继承，如果多个子模块可以去掉 -->
<optional>true</optional>
</dependency>
<!-- lombok: 简化bean代码的框架 -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<!-- spring-boot-starter-test: SpringBoot测试框架 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<plugins>
<!-- SpringBoot的maven打包插件 -->
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<!-- 明确指定一些插件的版本，以免受到 maven 版本的影响 -->
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>3.2.0</version>
</plugin>
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<plugin>
<artifactId>maven-site-plugin</artifactId>
<version>3.3</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.2</version>
</plugin>
</plugins>
</build>
</project>
- 创建启动类
启动类一定要在 src / main / java / 某一个包 下，并非直接在 src 目录下
package org.example;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class SpringStudy {
public static void main(String[] args) {
SpringApplication.run(SpringStudy.class,args);
}
}
- 创建 web 资源文件夹
在 resource 目录下创建 public 、static 两个包，这两个包下放入的是静态资源
后续在访问时 url 不需要加 public 或者 static
5. resource 目录下创建 Spring Boot 启动配置文件 application.properties
点击运行 启动类，正常情况下，控制台出现如下字符
"C:\Program Files\Java\jdk1.8.0_192\bin\java.exe" -Dspring.output.ansi.enabled=always "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA 2020.1.3\lib\idea_rt.jar=28748:D:\Program Files\JetBrains\IntelliJ IDEA 2020.1.3\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_192\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_192\jre\lib\rt.jar;D:\Users\李逍遥\IdeaProjects\spring02\target\classes;C:\Users\李逍遥\.m2\repository\org\springframework\boot\spring-boot-starter-web\2.3.5.RELEASE\spring-boot-starter-web-2.3.5.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\springframework\boot\spring-boot-starter\2.3.5.RELEASE\spring-boot-starter-2.3.5.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\springframework\boot\spring-boot-starter-logging\2.3.5.RELEASE\spring-boot-starter-logging-2.3.5.RELEASE.jar;C:\Users\李逍遥\.m2\repository\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;C:\Users\李逍遥\.m2\repository\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;C:\Users\李逍遥\.m2\repository\org\apache\logging\log4j\log4j-to-slf4j\2.13.3\log4j-to-slf4j-2.13.3.jar;C:\Users\李逍遥\.m2\repository\org\apache\logging\log4j\log4j-api\2.13.3\log4j-api-2.13.3.jar;C:\Users\李逍遥\.m2\repository\org\slf4j\jul-to-slf4j\1.7.30\jul-to-slf4j-1.7.30.jar;C:\Users\李逍遥\.m2\repository\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;C:\Users\李逍遥\.m2\repository\org\yaml\snakeyaml\1.26\snakeyaml-1.26.jar;C:\Users\李逍遥\.m2\repository\org\springframework\boot\spring-boot-starter-json\2.3.5.RELEASE\spring-boot-starter-json-2.3.5.RELEASE.jar;C:\Users\李逍遥\.m2\repository\com\fasterxml\jackson\core\jackson-databind\2.11.3\jackson-databind-2.11.3.jar;C:\Users\李逍遥\.m2\repository\com\fasterxml\jackson\core\jackson-annotations\2.11.3\jackson-annotations-2.11.3.jar;C:\Users\李逍遥\.m2\repository\com\fasterxml\jackson\core\jackson-core\2.11.3\jackson-core-2.11.3.jar;C:\Users\李逍遥\.m2\repository\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.11.3\jackson-datatype-jdk8-2.11.3.jar;C:\Users\李逍遥\.m2\repository\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.11.3\jackson-datatype-jsr310-2.11.3.jar;C:\Users\李逍遥\.m2\repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.11.3\jackson-module-parameter-names-2.11.3.jar;C:\Users\李逍遥\.m2\repository\org\springframework\spring-web\5.2.10.RELEASE\spring-web-5.2.10.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\springframework\spring-beans\5.2.10.RELEASE\spring-beans-5.2.10.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\springframework\spring-webmvc\5.2.10.RELEASE\spring-webmvc-5.2.10.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\springframework\spring-context\5.2.10.RELEASE\spring-context-5.2.10.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\springframework\spring-expression\5.2.10.RELEASE\spring-expression-5.2.10.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\springframework\boot\spring-boot-starter-undertow\2.3.5.RELEASE\spring-boot-starter-undertow-2.3.5.RELEASE.jar;C:\Users\李逍遥\.m2\repository\io\undertow\undertow-core\2.1.4.Final\undertow-core-2.1.4.Final.jar;C:\Users\李逍遥\.m2\repository\org\jboss\logging\jboss-logging\3.4.1.Final\jboss-logging-3.4.1.Final.jar;C:\Users\李逍遥\.m2\repository\org\jboss\xnio\xnio-api\3.8.0.Final\xnio-api-3.8.0.Final.jar;C:\Users\李逍遥\.m2\repository\org\wildfly\common\wildfly-common\1.5.2.Final\wildfly-common-1.5.2.Final.jar;C:\Users\李逍遥\.m2\repository\org\wildfly\client\wildfly-client-config\1.0.1.Final\wildfly-client-config-1.0.1.Final.jar;C:\Users\李逍遥\.m2\repository\org\jboss\xnio\xnio-nio\3.8.0.Final\xnio-nio-3.8.0.Final.jar;C:\Users\李逍遥\.m2\repository\org\jboss\threads\jboss-threads\3.1.0.Final\jboss-threads-3.1.0.Final.jar;C:\Users\李逍遥\.m2\repository\io\undertow\undertow-servlet\2.1.4.Final\undertow-servlet-2.1.4.Final.jar;C:\Users\李逍遥\.m2\repository\org\jboss\spec\javax\annotation\jboss-annotations-api_1.3_spec\2.0.1.Final\jboss-annotations-api_1.3_spec-2.0.1.Final.jar;C:\Users\李逍遥\.m2\repository\io\undertow\undertow-websockets-jsr\2.1.4.Final\undertow-websockets-jsr-2.1.4.Final.jar;C:\Users\李逍遥\.m2\repository\org\jboss\spec\javax\websocket\jboss-websocket-api_1.1_spec\2.0.0.Final\jboss-websocket-api_1.1_spec-2.0.0.Final.jar;C:\Users\李逍遥\.m2\repository\jakarta\servlet\jakarta.servlet-api\4.0.4\jakarta.servlet-api-4.0.4.jar;C:\Users\李逍遥\.m2\repository\org\glassfish\jakarta.el\3.0.3\jakarta.el-3.0.3.jar;C:\Users\李逍遥\.m2\repository\org\springframework\boot\spring-boot-starter-aop\2.3.5.RELEASE\spring-boot-starter-aop-2.3.5.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\springframework\spring-aop\5.2.10.RELEASE\spring-aop-5.2.10.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\aspectj\aspectjweaver\1.9.6\aspectjweaver-1.9.6.jar;C:\Users\李逍遥\.m2\repository\org\springframework\boot\spring-boot-devtools\2.3.5.RELEASE\spring-boot-devtools-2.3.5.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\springframework\boot\spring-boot\2.3.5.RELEASE\spring-boot-2.3.5.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\springframework\boot\spring-boot-autoconfigure\2.3.5.RELEASE\spring-boot-autoconfigure-2.3.5.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\projectlombok\lombok\1.18.16\lombok-1.18.16.jar;C:\Users\李逍遥\.m2\repository\org\slf4j\slf4j-api\1.7.30\slf4j-api-1.7.30.jar;C:\Users\李逍遥\.m2\repository\org\springframework\spring-core\5.2.10.RELEASE\spring-core-5.2.10.RELEASE.jar;C:\Users\李逍遥\.m2\repository\org\springframework\spring-jcl\5.2.10.RELEASE\spring-jcl-5.2.10.RELEASE.jar" org.example.SpringStudy
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.3.5.RELEASE)
2021-10-22 20:02:54.134 INFO 13528 --- [ restartedMain] org.example.SpringStudy : Starting SpringStudy on DESKTOP-AKHVU3E with PID 13528 (D:\Users\李逍遥\IdeaProjects\spring02\target\classes started by 李逍遥 in D:\Users\李逍遥\IdeaProjects\spring02)
2021-10-22 20:02:54.137 INFO 13528 --- [ restartedMain] org.example.SpringStudy : No active profile set, falling back to default profiles: default
2021-10-22 20:02:54.232 INFO 13528 --- [ restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
2021-10-22 20:02:54.232 INFO 13528 --- [ restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : For additional web related logging consider setting the 'logging.level.web' property to 'DEBUG'
2021-10-22 20:02:56.646 WARN 13528 --- [ restartedMain] io.undertow.websockets.jsr : UT026010: Buffer pool was not set on WebSocketDeploymentInfo, the default pool will be used
2021-10-22 20:02:56.676 INFO 13528 --- [ restartedMain] io.undertow.servlet : Initializing Spring embedded WebApplicationContext
2021-10-22 20:02:56.676 INFO 13528 --- [ restartedMain] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 2443 ms
如果出现错误，可能是 tomcat 端口（8080）被占用，此时可以在 resource 目录下的启动配置文件 application.properties 中添加如下字符（修改端口）
关于 application.properties 配置文件常用配置
#server.port=8888 端口被占用 修改端口
# 调试模式启动, 开发环境中, 可以看到更多的日志便于排查问题
debug=true
# 基础日志打印级别 ( 从低到高 )：
# 1. debug
# 2. info
# 3. warn
# 4. error
# 代码中, 使用 logger.debug / logger.info 打印日志, 日志级别以下的不会打印
logging.level.root=debug
# json 日期格式
spring.jackson.date-format=yyyy-MM-dd HH:mm:ss
# json 日期地区
spring.jackson.time-zone=GMT+8
# json 格式美化
spring.jackson.serialization.indent-output=true