springboot學習之構建簡單項目搭建
概述
相信對於Java開發者而言,spring和springMvc兩個框架一定不陌生,這兩個框架需要我們手動配置的地方非常多,各種的xml文件,properties文件,構建一個項目還是挺復雜的,在這種情況下,springboot應運而生,他能夠快速的構建spring項目,而且讓項目正常運行起來的配置文件非常少,甚至只需要幾個註解就可以運行整個項目。
總的說來,springboot項目可以打成jar包獨立運行部署,因為它內嵌servlet容器,之前spring,springMvc需要的大量依賴,可以通過starter來幫助我們簡化配置,當然還有其他好多優點,這裏就不一一贅述,小夥伴們可以自行搜索解答。
簡單項目構建
工具
eclipse maven
首先,我們新建一個maven項目,在eclipse左側右擊選擇new----》other,選擇新建Maven project
輸入group Id,artifact Id,點擊完成
這樣一個簡單的項目架子就完成了,但是啥都沒有,項目結構如下圖所示:
下面我們就開始配置搭建springboot項目。
1.添加依賴
完整porm代碼如下:
1 <project xmlns="http://maven.apache.org/POM/4.0.0" 2 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3View Codexsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 4 <modelVersion>4.0.0</modelVersion> 5 6 <groupId>com.cfxmn.springboot</groupId> 7 <artifactId>springbootDemo</artifactId> 8 <version>0.0.1-SNAPSHOT</version> 9<packaging>jar</packaging> 10 11 <!-- 通過繼承spring-boot-starter-parent項目來獲得一些合理的默認配置 --> 12 <parent> 13 <groupId>org.springframework.boot</groupId> 14 <artifactId>spring-boot-starter-parent</artifactId> 15 <version>1.5.6.RELEASE</version> 16 </parent> 17 18 <properties> 19 <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 20 </properties> 21 22 <dependencies> 23 <!-- Spring Boot Web 依賴 --> 24 <dependency> 25 <groupId>org.springframework.boot</groupId> 26 <artifactId>spring-boot-starter-web</artifactId> 27 </dependency> 28 29 <!-- Spring Boot Test 依賴 --> 30 <dependency> 31 <groupId>org.springframework.boot</groupId> 32 <artifactId>spring-boot-starter-test</artifactId> 33 <scope>test</scope> 34 </dependency> 35 <!-- 使用Lombok可以減少很多重復代碼的書寫。比如說getter/setter/toString等方法的編寫 --> 36 <dependency> 37 <groupId>org.projectlombok</groupId> 38 <artifactId>lombok</artifactId> 39 </dependency> 40 </dependencies> 41 </project>
下面我們新建一些包和添加項目的啟動類,如下圖所示:
其中,控制器DemoController的內容非常簡單,內容如下:
package com.cfxmn.springboot.springbootDemo.controller; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RestController; import lombok.extern.slf4j.Slf4j; @RestController @Slf4j public class DemoController { @PostMapping("/demo") public void demoTest() { // 這邊簡單起見,打印一下日誌 log.info("success call"); } }
可能有些同學對其中的幾個註解有些疑問,我這邊簡單說明下,
1.RestController
這個註解其實就是@ResponseBody + @Controller
2.PostMapping
這個註解其實就是@RequestMapping("xxxxxx", Method=RequestMethod.POST)
這兩個其實都是組合註解,簡化使用
我們再來看看,項目的啟動類SpringbootDemoApplication的內容:
package com.cfxmn.springboot.springbootDemo; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class SpringbootDemoApplication { public static void main(String[] args) { SpringApplication.run(SpringbootDemoApplication.class, args); } }
是的,你沒看錯,只要運行這個main方法,就能啟動這個spring項目,具體是怎麽啟動的容器,我們之後再分析,其實主要就是在註解SpringBootApplication上。
下面我們就來運行下,看下啟動日誌:
. ____ _ __ _ _
/\\ / ___‘_ __ _ _(_)_ __ __ _ \ \ \ ( ( )\___ | ‘_ | ‘_| | ‘_ \/ _` | \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) )
‘ |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.5.6.RELEASE)
2018-10-25 23:52:41.985 INFO 1700 --- [ main] c.c.s.s.SpringbootDemoApplication : Starting SpringbootDemoApplication on DESKTOP-KB78HJK with PID 1700 (E:\workspace\springbootDemo\target\classes started by gepengfa in E:\workspace\springbootDemo)
2018-10-25 23:52:41.990 INFO 1700 --- [ main] c.c.s.s.SpringbootDemoApplication : No active profile set, falling back to default profiles: default
2018-10-25 23:52:42.088 INFO 1700 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@7f416310: startup date [Thu Oct 25 23:52:42 CST 2018]; root of context hierarchy
2018-10-25 23:52:44.561 INFO 1700 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2018-10-25 23:52:44.584 INFO 1700 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2018-10-25 23:52:44.588 INFO 1700 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.16
2018-10-25 23:52:44.813 INFO 1700 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2018-10-25 23:52:44.813 INFO 1700 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 2733 ms
2018-10-25 23:52:45.074 INFO 1700 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: ‘dispatcherServlet‘ to [/]
2018-10-25 23:52:45.083 INFO 1700 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: ‘characterEncodingFilter‘ to: [/*]
2018-10-25 23:52:45.083 INFO 1700 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: ‘hiddenHttpMethodFilter‘ to: [/*]
2018-10-25 23:52:45.083 INFO 1700 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: ‘httpPutFormContentFilter‘ to: [/*]
2018-10-25 23:52:45.085 INFO 1700 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: ‘requestContextFilter‘ to: [/*]
2018-10-25 23:52:45.582 INFO 1700 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@7f416310: startup date [Thu Oct 25 23:52:42 CST 2018]; root of context hierarchy
2018-10-25 23:52:45.705 INFO 1700 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/demo],methods=[POST]}" onto public void com.cfxmn.springboot.springbootDemo.controller.DemoController.demoTest()
2018-10-25 23:52:45.710 INFO 1700 --- [ 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)
2018-10-25 23:52:45.711 INFO 1700 --- [ 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,javax.servlet.http.HttpServletResponse)
2018-10-25 23:52:45.759 INFO 1700 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-10-25 23:52:45.759 INFO 1700 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-10-25 23:52:45.817 INFO 1700 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-10-25 23:52:46.321 INFO 1700 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2018-10-25 23:52:46.529 INFO 1700 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2018-10-25 23:52:46.599 INFO 1700 --- [ main] c.c.s.s.SpringbootDemoApplication : Started SpringbootDemoApplication in 5.092 seconds (JVM running for 5.764)
從啟動日誌標黃的部分可以看出,項目啟動成功了,訪問端口默認是8080(這個端口是可以改動的)
下面我們通過postMan請求下,
查看控制臺
2018-10-25 23:59:26.385 INFO 1700 --- [nio-8080-exec-2] c.c.s.s.controller.DemoController : success call
說明調用成功。
到此,一個簡單的springboot項目就構建完成了,但這只是一個空的架子,內容還可載豐富。
下一篇文章我們主要來分析下,springboot啟動的相關源碼,敬請期待。
springboot學習之構建簡單項目搭建