springboot快速入门

SpringBoot简介

Spring Boot是由Pivotal团队提供的全新框架，其设计目的是用来简化新Spring应用的初始搭建以及开发过程。该框架使用了特定的方式来进行配置，从而使开发人员不再需要定义样板化的配置。通过这种方式，Spring Boot致力于在蓬勃发展的快速应用开发领域(rapid application development)成为领导者。

一、构建springboot项目

Spring官方提供了一个在线生成springboot的项目

地址：http://start.spring.io/

1.打开地址，按图选择 Maven项目 -> Java语言 -> 1.5.9版本（目前1.5.9为最高的正式版本），点击 “Generate Project” 生成项目

2、下载压缩包，解压并通过Eclipse导入（File -> Import -> Maven -> Existing Maven Projects -> 选择springboot项目 -> Finish）

3.导入成功，添加Controller代码

 import java.math.BigDecimal;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;

 @RestController
 public class CalculateController {

     @RequestMapping(value = "/add")
     public BigDecimal add(BigDecimal num1, BigDecimal num2){
         if(num1==null||num2==null){
             return BigDecimal.ZERO;
         }

         return num1.add(num2);
     }

 }

4.启动springboot服务

打开StartApplication类，并执行main方法（Run -> Run As -> Java Application）

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.9.RELEASE)

-- ::33.286  INFO  --- [           main] com.lianjinsoft.StartApplication         : Starting StartApplication on LAPTOP-1DF7S904 with PID  (E:\git\spring-boot\spring-boot-start\target\classes started by lianjinsoft in E:\git\spring-boot\spring-boot-start)
-- ::33.288  INFO  --- [           main] com.lianjinsoft.StartApplication         : No active profile set, falling back to default profiles: default
-- ::33.338  INFO  --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@50de0926: startup date [Fri Jan  :: CST ]; root of context hierarchy
-- ::35.401  INFO  --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s):  (http)
-- ::35.414  INFO  --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
-- ::35.415  INFO  --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.
-- ::35.544  INFO  --- [ost-startStop-] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
-- ::35.544  INFO  --- [ost-startStop-] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in  ms
-- ::35.785  INFO  --- [ost-startStop-] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
-- ::35.792  INFO  --- [ost-startStop-] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-01-05 14:53:35.793  INFO 22216 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2018-01-05 14:53:35.795  INFO 22216 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2018-01-05 14:53:35.795  INFO 22216 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2018-01-05 14:53:36.266  INFO 22216 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@50de0926: startup date [Fri Jan 05 14:53:33 CST 2018]; root of context hierarchy
2018-01-05 14:53:36.324  INFO 22216 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/add]}" onto public java.math.BigDecimal com.lianjinsoft.controller.CalculateController.add(java.math.BigDecimal,java.math.BigDecimal)
2018-01-05 14:53:36.327  INFO 22216 --- [           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)
2018-01-05 14:53:36.328  INFO 22216 --- [           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)
2018-01-05 14:53:36.372  INFO 22216 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-01-05 14:53:36.372  INFO 22216 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-01-05 14:53:36.404  INFO 22216 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
-- ::36.574  INFO  --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
-- ::36.693  INFO  --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s):  (http)
-- ::36.704  INFO  --- [           main] com.lianjinsoft.StartApplication         : Started StartApplication in 3.68 seconds (JVM running for 4.012)

5.验证

打开浏览器，访问地址 http://localhost:8080/add?num1=3&num2=4

6.测试成功，so easy~

备注：

1）springboot默认集成tomcat容器，通过SpringApplication.run启动

2）springboot默认服务不带上下文路径（通过http://ip:port/访问）

3）springboot默认端口为：8080

源代码：https://gitee.com/skychenjiajun/spring-boot