概述
相信对于Java开发者而言,spring和springMvc两个框架一定不陌生,这两个框架需要我们手动配置的地方非常多,各种的xml文件,properties文件,构建一个项目还是挺复杂的,在这种情况下,springboot应运而生,他能够快速的构建spring项目,而且让项目正常运行起来的配置文件非常少,甚至只需要几个注解就可以运行整个项目。
总的说来,springboot项目可以打成jar包独立运行部署,因为它内嵌servlet容器,之前spring,springMvc需要的大量依赖,可以通过starter来帮助我们简化配置,当然还有其他好多优点,这里就不一一赘述,小伙伴们可以自行搜索解答。
简单项目构建
工具
eclipse maven
首先,我们新建一个maven项目,在eclipse左侧右击选择new----》other,选择新建Maven project
输入group Id,artifact Id,点击完成
这样一个简单的项目架子就完成了,但是啥都没有,项目结构如下图所示:
下面我们就开始配置搭建springboot项目。
1.添加依赖
完整porm代码如下:
1 <project xmlns="http://maven.apache.org/POM/4.0.0" 2 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xsi: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 <!-- 通过继承spring-boot-starter-parent项目来获得一些合理的默认配置 --> 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 依赖 --> 24 <dependency> 25 <groupId>org.springframework.boot</groupId> 26 <artifactId>spring-boot-starter-web</artifactId> 27 </dependency> 28 29 <!-- Spring Boot Test 依赖 --> 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可以减少很多重复代码的书写。比如说getter/setter/toString等方法的编写 --> 36 <dependency> 37 <groupId>org.projectlombok</groupId> 38 <artifactId>lombok</artifactId> 39 </dependency> 40 </dependencies> 41 </project>
下面我们新建一些包和添加项目的启动类,如下图所示:
其中,控制器DemoController的内容非常简单,内容如下:
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() { // 这边简单起见,打印一下日志 log.info("success call"); } }
可能有些同学对其中的几个注解有些疑问,我这边简单说明下,
1.RestController
这个注解其实就是@ResponseBody + @Controller
2.PostMapping
这个注解其实就是@RequestMapping("xxxxxx", Method=RequestMethod.POST)
这两个其实都是组合注解,简化使用
我们再来看看,项目的启动类SpringbootDemoApplication的内容:
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,你没看错,只要运行这个main方法,就能启动这个spring项目,具体是怎么启动的容器,我们之后再分析,其实主要就是在注解SpringBootApplication上。
下面我们就来运行下,看下启动日志:
. ____ _ __ _ _ /\\ / ___‘_ __ _ _(_)_ __ __ _ \ \ \ ( ( )\___ | ‘_ | ‘_| | ‘_ \/ _` | \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ‘ |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: 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[email protected]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[email protected]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)
从启动日志标黄的部分可以看出,项目启动成功了,访问端口默认是8080(这个端口是可以改动的)
下面我们通过postMan请求下,
查看控制台
2018-10-25 23:59:26.385 INFO 1700 --- [nio-8080-exec-2] c.c.s.s.controller.DemoController : success call
说明调用成功。
到此,一个简单的springboot项目就构建完成了,但这只是一个空的架子,内容还可载丰富。
下一篇文章我们主要来分析下,springboot启动的相关源码,敬请期待。
原文地址:https://www.cnblogs.com/xiaobaobei/p/9853712.html