SpringBoot 第一个项目

柔光的暖阳◎ 2022-06-12 06:13 227阅读 0赞

Spring的发展总是能引领潮流，SpringBoot的问世使开发的门槛有降低了不少，会不会将来开发啥都不用做了呢？  
下面让我们来通过一个小项目来看下，SpringBoot到底有多方便。

**1.构建项目：**  
构建SpringBoot项目一般采用两种方式：gradle、maven；官网的所有示例都是使用gradle；工作中一直使用maven，故下面的示例使用maven。  
创建一个maven项目，对应的pom.xml 文件为：

<parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.4.3.RELEASE</version>
        </parent>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-devtools</artifactId>
                <optional>true</optional>
            </dependency>   
        </dependencies>
    
          
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>

**2.创建启动类：**

import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    public class ComputeServiceApplication { 
    
        public static void main(String[] args) {
            SpringApplication.run(ComputeServiceApplication.class, args);
        }
    }

**3.创建一个Controller类：**

import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    @RequestMapping("/springboot")
    public class ComputeController {
        @RequestMapping(value = "/{name}" ,method = RequestMethod.GET)
        public String add(@PathVariable("name") String name) {
    
            return "Hello "+name;
        }
    }

**4.运行main函数：**

2017-07-17 18:08:50.586  INFO 29264 --- [  restartedMain] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@25316b3d: startup date [Mon Jul 17 18:08:50 CST 2017]; root of context hierarchy
    2017-07-17 18:08:51.052  INFO 29264 --- [  restartedMain] f.a.AutowiredAnnotationBeanPostProcessor : JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
    2017-07-17 18:08:51.203  INFO 29264 --- [  restartedMain] trationDelegate$BeanPostProcessorChecker : Bean 'configurationPropertiesRebinderAutoConfiguration' of type [class org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration$$EnhancerBySpringCGLIB$$9dedd6fe] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
    
      .   ____          _            __ _ _
     /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
    ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
     \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
      '  |____| .__|_| |_|_| |_\__, | / / / /
     =========|_|==============|___/=/_/_/_/
     :: Spring Boot ::        (v1.4.3.RELEASE)
    
    2017-07-17 18:08:52.086  INFO 29264 --- [  restartedMain] com.my.ComputeServiceApplication         : No active profile set, falling back to default profiles: default
    2017-07-17 18:08:52.110  INFO 29264 --- [  restartedMain] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@75ae055a: startup date [Mon Jul 17 18:08:52 CST 2017]; parent: org.springframework.context.annotation.AnnotationConfigApplicationContext@25316b3d
    2017-07-17 18:08:53.318  INFO 29264 --- [  restartedMain] o.s.b.f.s.DefaultListableBeanFactory     : Overriding bean definition for bean 'retryTemplate' with a different definition: replacing [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.cloud.client.loadbalancer.LoadBalancerAutoConfiguration$RetryAutoConfiguration; factoryMethodName=retryTemplate; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/cloud/client/loadbalancer/LoadBalancerAutoConfiguration$RetryAutoConfiguration.class]] with [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.cloud.netflix.feign.ribbon.FeignRibbonClientAutoConfiguration; factoryMethodName=retryTemplate; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/cloud/netflix/feign/ribbon/FeignRibbonClientAutoConfiguration.class]]
    2017-07-17 18:08:53.355  WARN 29264 --- [  restartedMain] o.s.c.a.ConfigurationClassPostProcessor  : Cannot enhance @Configuration bean definition 'refreshScope' since its singleton instance has been created too early. The typical cause is a non-static @Bean method with a BeanDefinitionRegistryPostProcessor return type: Consider declaring such methods as 'static'.
    2017-07-17 18:08:53.550  INFO 29264 --- [  restartedMain] o.s.cloud.context.scope.GenericScope     : BeanFactory id=ed6125b6-23f5-37eb-bf39-cba4b79f07b9
    2017-07-17 18:08:53.656  INFO 29264 --- [  restartedMain] f.a.AutowiredAnnotationBeanPostProcessor : JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
    2017-07-17 18:08:53.756  INFO 29264 --- [  restartedMain] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration' of type [class org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration$$EnhancerBySpringCGLIB$$9dedd6fe] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
    2017-07-17 18:08:54.726  INFO 29264 --- [  restartedMain] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 80 (http)
    2017-07-17 18:08:54.762  INFO 29264 --- [  restartedMain] o.apache.catalina.core.StandardService   : Starting service Tomcat
    2017-07-17 18:08:54.763  INFO 29264 --- [  restartedMain] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.6
    2017-07-17 18:08:55.102  INFO 29264 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
    2017-07-17 18:08:55.102  INFO 29264 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2992 ms
    2017-07-17 18:08:55.389  INFO 29264 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
    2017-07-17 18:08:55.394  INFO 29264 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
    2017-07-17 18:08:55.395  INFO 29264 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
    2017-07-17 18:08:55.396  INFO 29264 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
    2017-07-17 18:08:55.398  INFO 29264 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]

**5.浏览器查看运行结果：**  
![这里写图片描述][SouthEast]

成功了，就是这么简单。

[SouthEast]: /images/20220612/93f25beb574b42e28ac6ff39ab5fea5a.png