Spring boot Hello word 教程
对于开发界 万事都是开头 Hellword, 我们也来一个spring boot Helloword 教程！
-
第一步，当然是在pom.xml 引入 spring boot jar， 我使用的是 undertow
org.springframework.boot spring-boot-starter-parent 1.5.22.RELEASE org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-tomcat org.springframework.boot spring-boot-starter-undertow
完整pom.xml 配置
<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>com.pangugle</groupId>
<artifactId>testspringboot</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>testspringboot</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.22.RELEASE</version>
</parent>
<dependencies>
<!-- spring -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-undertow</artifactId>
</dependency>
</dependencies>
</project>
编写spring boot main 方法启动器
package com.pangugle.testspringboot;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class App
{
public static void main( String[] args )
{
SpringApplication.run(App.class, args);
}
}
上面我们使用Annotaion 注解
@SpringBootApplication
来配置spring boot 启动器; 然后就是
SpringApplication.run(App.class, args);
这句就是启动 spring boot 框架，并运行服务，服务端口为8080,这是默认配置的!
编写一个 Helloword mvc， 并在浏览器上访问
package com.pangugle.testspringboot;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HelloController {
@RequestMapping("/sayHello")
public String sayHello()
{
return "hello spring boot!";
}
}
- @RestController 注解表示返回一个字符串，不返回页面
- @RequestMapping 注解表示 访问路径,
- sayHello 访问url : 127.0.0.1:8080/sayHello
注意： spring boot 默认端口是 8080
运行 App，在控制台输出如下:
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.5.22.RELEASE)
2020-09-12 13:37:12.398 INFO 14068 --- [ main] com.pangugle.testspringboot.App : Starting App on SD-20191007VAAX with PID 14068 (D:\dev\workspace\testspringboot\target\classes started by Administrator in D:\dev\workspace\testspringboot)
2020-09-12 13:37:12.400 INFO 14068 --- [ main] com.pangugle.testspringboot.App : No active profile set, falling back to default profiles: default
2020-09-12 13:37:12.429 INFO 14068 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@3d8314f0: startup date [Sat Sep 12 13:37:12 CST 2020]; root of context hierarchy
2020-09-12 13:37:13.285 INFO 14068 --- [ main] org.xnio : XNIO version 3.3.8.Final
2020-09-12 13:37:13.297 INFO 14068 --- [ main] org.xnio.nio : XNIO NIO Implementation Version 3.3.8.Final
2020-09-12 13:37:13.395 WARN 14068 --- [ main] io.undertow.websockets.jsr : UT026009: XNIO worker was not set on WebSocketDeploymentInfo, the default worker will be used
2020-09-12 13:37:13.395 WARN 14068 --- [ main] io.undertow.websockets.jsr : UT026010: Buffer pool was not set on WebSocketDeploymentInfo, the default pool will be used
2020-09-12 13:37:13.411 INFO 14068 --- [ main] io.undertow.servlet : Initializing Spring embedded WebApplicationContext
2020-09-12 13:37:13.412 INFO 14068 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 983 ms
2020-09-12 13:37:13.465 INFO 14068 --- [ main] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/]
2020-09-12 13:37:13.468 INFO 14068 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2020-09-12 13:37:13.469 INFO 14068 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2020-09-12 13:37:13.469 INFO 14068 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2020-09-12 13:37:13.469 INFO 14068 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2020-09-12 13:37:13.636 INFO 14068 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@3d8314f0: startup date [Sat Sep 12 13:37:12 CST 2020]; root of context hierarchy
2020-09-12 13:37:13.677 INFO 14068 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/sayHello]}" onto public java.lang.String com.pangugle.testspringboot.HelloController.sayHello()
2020-09-12 13:37:13.679 INFO 14068 --- [ 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)
2020-09-12 13:37:13.679 INFO 14068 --- [ 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)
2020-09-12 13:37:13.695 INFO 14068 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2020-09-12 13:37:13.695 INFO 14068 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2020-09-12 13:37:13.717 INFO 14068 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2020-09-12 13:37:13.799 INFO 14068 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2020-09-12 13:37:13.837 INFO 14068 --- [ main] b.c.e.u.UndertowEmbeddedServletContainer : Undertow started on port(s) 8080 (http)
2020-09-12 13:37:13.840 INFO 14068 --- [ main] com.pangugle.testspringboot.App : Started App in 1.638 seconds (JVM running for 1.875)
2020-09-12 13:37:31.240 INFO 14068 --- [ XNIO-2 task-1] io.undertow.servlet : Initializing Spring FrameworkServlet 'dispatcherServlet'
2020-09-12 13:37:31.240 INFO 14068 --- [ XNIO-2 task-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization started
2020-09-12 13:37:31.246 INFO 14068 --- [ XNIO-2 task-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization completed in 6 ms
最后在浏览器访问:
http://127.0.0.1:8080/sayHello
然后就可以看到
hello spring boot!
至此 spring boot hello word 教程就完成了！是不是很简单呢？
