今天说下怎么创建Java后端框架Spring Boot的项目

使用java编程，就不得不提到久负盛名的Java后端框架 Spring Boot 今天来跟大家说下怎么创建Spring Boot的第一个项目，都需要做哪些准备吧。

首先介绍下 Spring Boot 主要提供了以下功能:

1.为所有基于 Spring的 java开发提供方便快捷的入门体验

2.开箱即用，有自己自定义的配置就是用自己的，没有就使用官方提供的默认的

3.提供了一系列通用的非功能性的功能，包含: 

   3.1 嵌入式服务器

   3.2 安全管理

   3.3 健康检测

4.不需要xml配置，且spring cloud 微服务也是基于Spring Boot框架的

所以了解Spring Boot框架对我们了解java及微服务等都是非常好的。

前期准备:

1. ide建议使用idea, 可以在网上下载。社区版或者正式版都是可以的。
2. 在电脑上配置好java环境，建议用1.8或者8.0的
3. 打开idea，然后在安装插件 Spring Assistant
4. 下载Maven包并包装，尽量不要使用idea自带的maven包

安装完插件后，就可以创建Spring Boot项目了

创建好后，就会导入 spring boot的各种包。需要等待差不多10分钟左右，有时候idea会出现假死的情况，可以强制退出后重新进入。

所有包都正常导入后，你会发现没法正常运行程序，因为你还没有正确的导入Maven包。

点击idea右边靠边的maven处，会显示maven的选项

点击其中像钳子一样的图标，会进入Maven的设置

在这里需要将Maven的路径设置为你安装的地址;
users settings file可以设置为maven包里的settings文件，也可以自己修改

local resposistory 可以设置为maven包里的resposistory文件

然后就一直next下去

可以在刚才的Maven页面先clean下，然后再compile

clean主要是为了清理不必要的配置垃圾文件，compile是将maven的配置文件都导入进来。

然后我们就准备启动Spring boot

启动的时候可能会遇到一个问题，就是端口号冲突。Spring boot的默认port是8080，而很多软件或者系统的监听端口都是 8080，这时我们可以修改下Spring boot的监听端口。

src->main->resources-> application.properties

写上 server.port = 8004

那么Spring boot的监听接口就是8004了

现在，让我们运行下 

@SpringBootApplicationpublic class DemoApplication {

   public static void main(String[] args) {
      SpringApplication.run(DemoApplication.class, args);   }

}

/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/bin/java "-javaagent:/Applications/IntelliJ IDEA CE.app/Contents/lib/idea_rt.jar=51980:/Applications/IntelliJ IDEA CE.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath /Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/charsets.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/deploy.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/ext/cldrdata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/ext/dnsns.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/ext/jaccess.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/ext/jfxrt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/ext/localedata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/ext/nashorn.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/ext/sunec.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/ext/sunjce_provider.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/ext/sunpkcs11.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/ext/zipfs.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/javaws.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/jce.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/jfr.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/jfxswt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/jsse.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/management-agent.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/plugin.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/resources.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/jre/lib/rt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/lib/ant-javafx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/lib/dt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/lib/javafx-mx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/lib/jconsole.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/lib/packager.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/lib/sa-jdi.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/lib/tools.jar:/Users/lg/Desktop/com.guazi.project/demo/target/test-classes:/Users/lg/Desktop/com.guazi.project/demo/target/classes:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/springframework/boot/spring-boot-starter-web/2.3.1.RELEASE/spring-boot-starter-web-2.3.1.RELEASE.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/springframework/boot/spring-boot-starter/2.3.1.RELEASE/spring-boot-starter-2.3.1.RELEASE.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/springframework/boot/spring-boot/2.3.1.RELEASE/spring-boot-2.3.1.RELEASE.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/springframework/boot/spring-boot-autoconfigure/2.3.1.RELEASE/spring-boot-autoconfigure-2.3.1.RELEASE.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/springframework/boot/spring-boot-starter-logging/2.3.1.RELEASE/spring-boot-starter-logging-2.3.1.RELEASE.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/ch/qos/logback/logback-core/1.2.3/logback-core-1.2.3.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/apache/logging/log4j/log4j-to-slf4j/2.13.3/log4j-to-slf4j-2.13.3.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/apache/logging/log4j/log4j-api/2.13.3/log4j-api-2.13.3.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/slf4j/jul-to-slf4j/1.7.30/jul-to-slf4j-1.7.30.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/jakarta/annotation/jakarta.annotation-api/1.3.5/jakarta.annotation-api-1.3.5.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/yaml/snakeyaml/1.26/snakeyaml-1.26.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/springframework/boot/spring-boot-starter-json/2.3.1.RELEASE/spring-boot-starter-json-2.3.1.RELEASE.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/com/fasterxml/jackson/core/jackson-databind/2.11.0/jackson-databind-2.11.0.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/com/fasterxml/jackson/core/jackson-annotations/2.11.0/jackson-annotations-2.11.0.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/com/fasterxml/jackson/core/jackson-core/2.11.0/jackson-core-2.11.0.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/com/fasterxml/jackson/datatype/jackson-datatype-jdk8/2.11.0/jackson-dataty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bjenesis/objenesis/2.6/objenesis-2.6.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/mockito/mockito-junit-jupiter/3.3.3/mockito-junit-jupiter-3.3.3.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/skyscreamer/jsonassert/1.5.0/jsonassert-1.5.0.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/com/vaadin/external/google/android-json/0.0.20131108.vaadin1/android-json-0.0.20131108.vaadin1.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/springframework/spring-core/5.2.7.RELEASE/spring-core-5.2.7.RELEASE.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/springframework/spring-jcl/5.2.7.RELEASE/spring-jcl-5.2.7.RELEASE.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/springframework/spring-test/5.2.7.RELEASE/spring-test-5.2.7.RELEASE.jar:/Users/lg/Desktop/com.guazi.project/apache-maven-3.6.1/respository/org/xmlunit/xmlunit-core/2.7.0/xmlunit-core-2.7.0.jar com.example.demo.DemoApplication

  .   ____          _            __ _ _

 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \

( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \

 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )

  '  |____| .__|_| |_|_| |_\__, | / / / /

 =========|_|==============|___/=/_/_/_/

 :: Spring Boot ::        (v2.3.1.RELEASE)

2020-07-07 19:25:16.556  INFO 12149 --- [           main] com.example.demo.DemoApplication         : Starting DemoApplication on ligangdeMacBook-Pro.local with PID 12149 (/Users/lg/Desktop/com.guazi.project/demo/target/classes started by lg in /Users/lg/Desktop/com.guazi.project/demo)

2020-07-07 19:25:16.559  INFO 12149 --- [           main] com.example.demo.DemoApplication         : No active profile set, falling back to default profiles: default

2020-07-07 19:25:18.092  INFO 12149 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8004 (http)

2020-07-07 19:25:18.110  INFO 12149 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]

2020-07-07 19:25:18.110  INFO 12149 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.36]

2020-07-07 19:25:18.276  INFO 12149 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext

2020-07-07 19:25:18.277  INFO 12149 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1637 ms

2020-07-07 19:25:18.511  INFO 12149 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'

2020-07-07 19:25:18.808  INFO 12149 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8004 (http) with context path ''

2020-07-07 19:25:18.835  INFO 12149 --- [           main] com.example.demo.DemoApplication         : Started DemoApplication in 2.902 seconds (JVM running for 3.648)

2020-07-07 19:27:56.786  INFO 12149 --- [extShutdownHook] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'applicationTaskExecutor'

Process finished with exit code 130 (interrupted by signal 2: SIGINT)

有这些就说明Spring boot已经启动了。

好了，今天先到这里吧