項目結構
項目基於Maven管理,注意使用了父pom
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.3.0.RELEASE</version> <relativePath /> </parent>
pom.xml
<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> <groupId>test.demo</groupId> <artifactId>springboot</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springboot</name> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.3.0.RELEASE</version> <relativePath /> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> </project>
App.class
package hello; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController; @EnableAutoConfiguration @RestController public class App { public static void main(String[] args) { SpringApplication.run(App.class, args); } @RequestMapping(value = "/test", method = RequestMethod.GET) public String get() { return "get"; } @RequestMapping(value = "/post", method = RequestMethod.POST) public String post() { return "post"; } }
@EnableAutoConfiguration注解的作用在於讓 Spring Boot 根據應用所聲明的依賴來對 Spring 框架進行自動配置
@EnableAutoConfiguration注解上注釋的翻譯
自動配置Spring上下文,企圖猜測所需要的Bean,將classpath和你所定義的Bean加入到IOC容器,比如你有tomcat-embedded.jar在你的classpath上
那麼看起來你需要一個TomcatEmbeddedServletContainerFactory,那麼SpringBoot會給你生成一個這個類的Bean(除非你已經生成這個類的Bean)
你可以使用exclude來指定那些Bean不需要SpringBoot幫你生成Bean
public @interface EnableAutoConfiguration { /** * Exclude specific auto-configuration classes such that they will never be applied. * @return the classes to exclude */ Class<?>[] exclude() default {}; /** * Exclude specific auto-configuration class names such that they will never be * applied. * @return the class names to exclude * @since 1.3.0 */ String[] excludeName() default {}; }
在你的root package上使用這個注解,它會將這個目錄下所有的子目錄和類掃描一遍
@RestController和@RequestMapper注解由SpringMvc提供,用於創建Rest服務
關於@RequestMapper注解
value表示路徑映射,method說明請求這個路徑的Http方法
啟動日志解讀
2016-03-11 13:58:02.399 INFO 5776 --- [ main] hello.App : Starting App on zzzzzz with PID 5776 (E:\space\spring\springboot\target\classes started by zzzzz in E:\space\spring\springboot) 2016-03-11 13:58:02.404 INFO 5776 --- [ main] hello.App : No profiles are active 2016-03-11 13:58:02.508 INFO 5776 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@481a15ff: startup date [Fri Mar 11 13:58:02 CST 2016]; root of context hierarchy 2016-03-11 13:58:03.807 INFO 5776 --- [ main] o.s.b.f.s.DefaultListableBeanFactory : Overriding bean definition for bean 'beanNameViewResolver' 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.boot.autoconfigure.web.ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration; factoryMethodName=beanNameViewResolver; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/web/ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration.class]] with [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter; factoryMethodName=beanNameViewResolver; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter.class]] 2016-03-11 13:58:05.107 INFO 5776 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http) 2016-03-11 13:58:05.126 INFO 5776 --- [ main] o.apache.catalina.core.StandardService : Starting service Tomcat 2016-03-11 13:58:05.128 INFO 5776 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.0.28 2016-03-11 13:58:05.268 INFO 5776 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2016-03-11 13:58:05.268 INFO 5776 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 2769 ms 2016-03-11 13:58:05.673 INFO 5776 --- [ost-startStop-1] o.s.b.c.e.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/] 2016-03-11 13:58:05.680 INFO 5776 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*] 2016-03-11 13:58:05.681 INFO 5776 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*] 2016-03-11 13:58:05.681 INFO 5776 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*] 2016-03-11 13:58:05.682 INFO 5776 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*] 2016-03-11 13:58:06.022 INFO 5776 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@481a15ff: startup date [Fri Mar 11 13:58:02 CST 2016]; root of context hierarchy 2016-03-11 13:58:06.115 INFO 5776 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/test],methods=[GET]}" onto public java.lang.String hello.App.get() 2016-03-11 13:58:06.116 INFO 5776 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/post],methods=[POST]}" onto public java.lang.String hello.App.post() 2016-03-11 13:58:06.121 INFO 5776 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest) 2016-03-11 13:58:06.121 INFO 5776 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest) 2016-03-11 13:58:06.178 INFO 5776 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler] 2016-03-11 13:58:06.178 INFO 5776 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler] 2016-03-11 13:58:06.225 INFO 5776 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler] 2016-03-11 13:58:06.363 INFO 5776 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup 2016-03-11 13:58:06.468 INFO 5776 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http) 2016-03-11 13:58:06.473 INFO 5776 --- [ main] hello.App : Started App in 4.736 seconds (JVM running for 5.798)
注意查看紅色的部分,dispatcherServlet是SpringWeb的核心Servlet,所有進入SpringWeb的請求都由這個Servelt的service方法進入
2016-03-11 13:58:06.115 INFO 5776 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/test],methods=[GET]}" onto public java.lang.String hello.App.get() 2016-03-11 13:58:06.116 INFO 5776 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/post],methods=[POST]}" onto public java.lang.String hello.App.post()
表示我們聲明的路徑映射