spring-boo hello world程序

作为一个程序猿,使用了spring好多年,现在有了spring-boot,也想尝尝鲜。

初听spring-boot,觉得很神秘,实际上就是集合了很多组件,再加上一些boot开发的启动和粘合程序。 个人见解,不一定对。

构建过程

使用 Spring Initializr ,我使用idea构建的,在新项目里面有一个Spring Initializr 选项,如图:

spring-boo hello world程序

设置项目属性,如图:

spring-boo hello world程序

选择spring-boot组件:

spring-boo hello world程序

设置项目名:

spring-boo hello world程序

完成就可以了

第一个程序

新建Java程序

package com.sun.boot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.web.bind.annotation.*; @RestController
@EnableAutoConfiguration
public class Application { @RequestMapping("/helloworld")
public String home() {
return "Hello World!";
}
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}

查看build.gradle文件

buildscript {
ext {
springBootVersion = '1.5.4.RELEASE'
}
repositories {
mavenCentral()
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
}
} apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot' version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8 repositories {
mavenCentral()
} dependencies {
compile('org.springframework.boot:spring-boot-starter-web')
runtime('mysql:mysql-connector-java')
testCompile('org.springframework.boot:spring-boot-starter-test')
}

程序结构如下:

spring-boo hello world程序

运行

运行Application,输出如下:

  .   ____          _            __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.5.4.RELEASE) 2017-07-19 08:22:36.552 INFO 8372 --- [ main] com.sun.boot.Application : Starting Application on sunzuoquan-Inspiron-7466 with PID 8372 (/home/sunzuoquan/IdeaProjects/demo/build/classes/java/main started by sunzuoquan in /home/sunzuoquan/IdeaProjects/demo)
2017-07-19 08:22:36.583 INFO 8372 --- [ main] com.sun.boot.Application : No active profile set, falling back to default profiles: default
2017-07-19 08:22:37.041 INFO 8372 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@43bd930a: startup date [Wed Jul 19 08:22:36 CST 2017]; root of context hierarchy
2017-07-19 08:22:42.185 INFO 8372 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2017-07-19 08:22:42.210 INFO 8372 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2017-07-19 08:22:42.211 INFO 8372 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.15
2017-07-19 08:22:42.747 INFO 8372 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2017-07-19 08:22:42.748 INFO 8372 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 5760 ms
2017-07-19 08:22:42.877 INFO 8372 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/]
2017-07-19 08:22:42.880 INFO 8372 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2017-07-19 08:22:42.880 INFO 8372 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2017-07-19 08:22:42.880 INFO 8372 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2017-07-19 08:22:42.881 INFO 8372 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2017-07-19 08:22:43.338 INFO 8372 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@43bd930a: startup date [Wed Jul 19 08:22:36 CST 2017]; root of context hierarchy
2017-07-19 08:22:43.401 INFO 8372 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/helloworld]}" onto public java.lang.String com.sun.boot.Application.home()
2017-07-19 08:22:43.405 INFO 8372 --- [ 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)
2017-07-19 08:22:43.405 INFO 8372 --- [ 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)
2017-07-19 08:22:43.421 INFO 8372 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-07-19 08:22:43.421 INFO 8372 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-07-19 08:22:43.440 INFO 8372 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-07-19 08:22:43.634 INFO 8372 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2017-07-19 08:22:44.043 INFO 8372 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2017-07-19 08:22:44.065 INFO 8372 --- [ main] com.sun.boot.Application : Started Application in 9.217 seconds (JVM running for 15.872)

从日志可以看出,Tomcat started on port(s): 8080,spring-boot内部启动了tomcat,监听8080端口。
打开浏览器,访问:http://localhost:8080/helloworld
浏览器输出如下:

spring-boo hello world程序

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