SpringBoot入门第一天
采用STS工具进行开发。学习前请先安装STS工具。
第一步首先建立一个简单的MAVEN项目
选择NEXT,出现如下界面
在这个界面中输入group id,artifact id的信息。其中artifact id为项目名,点击Finish项目创建完成。
第二步配置项目相关的信息
打开项目的POM.xml文件,将项目内容修改如下
<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.qlys</groupId>
<artifactId>spring-learn</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.15.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
</project>
在上面的配置中parent指定项目为SpringBoot项目,spring-boot-starter-web的依赖为指定项目为WEB项目,引入SpringMVC相关的依赖信息。另外如果项目想通过jetty启动可以加入spring-boot-starter-jetty的依赖。不加这个依赖,系统默认通过tomcat进行启动。
配置好pom.xml文件后,我们可以创建一个Controller。代码如下
package com.qlys.controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class TestController {
@RequestMapping("/")
public String index() {
return "hello word";
}
}
然后创建一个启动类,启动类可以放在根目录下,代码如下:
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
@SpringBootApplication
@ComponentScan("com.qlys")
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
在代码中注解 SpringBootApplication用于指定这是一个启动类,注解ComponentScan用于指定扫描的包信息。相当于SpringMVC中的context:component-scan 配置信息。
完成上面的二步操作,我们的第一个SpringBoot项目就可以正常启动了。在Application类中右击,选择run as出来如下界面,选择java application即可。项目开始启动了
控制台显示如下信息就表示我们的Spring Boot项目启动成功,可以通过http://127.0.0.1:8080/进行测试查看是否能够访问正常。
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.5.15.RELEASE)
2018-09-26 16:55:31.379 INFO 158480 --- [ main] Application : Starting Application on DESKTOP-O3TGTFN with PID 158480 (E:\sts-3.9.0.RELEASE\E\workspace\spring-learn\target\classes started by lenovo in E:\sts-3.9.0.RELEASE\E\workspace\spring-learn)
2018-09-26 16:55:31.381 INFO 158480 --- [ main] Application : No active profile set, falling back to default profiles: default
2018-09-26 16:55:31.425 INFO 158480 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot[email protected]4f638935: startup date [Wed Sep 26 16:55:31 CST 2018]; root of context hierarchy
2018-09-26 16:55:32.301 INFO 158480 --- [ main] org.eclipse.jetty.util.log : Logging initialized @1714ms to org.eclipse.jetty.util.log.Slf4jLog
2018-09-26 16:55:32.539 INFO 158480 --- [ main] e.j.JettyEmbeddedServletContainerFactory : Server initialized with port: 8080
2018-09-26 16:55:32.541 INFO 158480 --- [ main] org.eclipse.jetty.server.Server : jetty-9.4.11.v20180605; built: 2018-06-05T18:24:03.829Z; git: d5fc0523cfa96bfebfbda19606cad384d772f04c; jvm 1.8.0_45-b14
2018-09-26 16:55:32.679 INFO 158480 --- [ main] org.eclipse.jetty.server.session : DefaultSessionIdManager workerName=node0
2018-09-26 16:55:32.679 INFO 158480 --- [ main] org.eclipse.jetty.server.session : No SessionScavenger set, using defaults
2018-09-26 16:55:32.682 INFO 158480 --- [ main] org.eclipse.jetty.server.session : node0 Scavenging every 600000ms
2018-09-26 16:55:32.687 INFO 158480 --- [ main] o.e.j.s.h.ContextHandler.application : Initializing Spring embedded WebApplicationContext
2018-09-26 16:55:32.687 INFO 158480 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1265 ms
2018-09-26 16:55:32.778 INFO 158480 --- [ main] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/]
2018-09-26 16:55:32.780 INFO 158480 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-09-26 16:55:32.780 INFO 158480 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2018-09-26 16:55:32.780 INFO 158480 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2018-09-26 16:55:32.780 INFO 158480 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2018-09-26 16:55:32.785 INFO 158480 --- [ main] o.e.jetty.server.handler.ContextHandler : Started [email protected]{application,/,[file:///C:/Users/lenovo/AppData/Local/Temp/jetty-docbase.4938443747148418953.8080/],AVAILABLE}
2018-09-26 16:55:32.786 INFO 158480 --- [ main] org.eclipse.jetty.server.Server : Started @2200ms
2018-09-26 16:55:33.060 INFO 158480 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot[email protected]4f638935: startup date [Wed Sep 26 16:55:31 CST 2018]; root of context hierarchy
2018-09-26 16:55:33.117 INFO 158480 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/]}" onto public java.lang.String com.qlys.controller.TestController.index()
2018-09-26 16:55:33.120 INFO 158480 --- [ 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)
2018-09-26 16:55:33.122 INFO 158480 --- [ 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)
2018-09-26 16:55:33.152 INFO 158480 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-09-26 16:55:33.152 INFO 158480 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-09-26 16:55:33.186 INFO 158480 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-09-26 16:55:33.310 INFO 158480 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2018-09-26 16:55:33.329 INFO 158480 --- [ main] o.e.j.s.h.ContextHandler.application : Initializing Spring FrameworkServlet 'dispatcherServlet'
2018-09-26 16:55:33.330 INFO 158480 --- [ main] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization started
2018-09-26 16:55:33.341 INFO 158480 --- [ main] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization completed in 8 ms
2018-09-26 16:55:33.405 INFO 158480 --- [ main] o.e.jetty.server.AbstractConnector : Started [email protected]{HTTP/1.1,[http/1.1]}{0.0.0.0:8080}
2018-09-26 16:55:33.406 INFO 158480 --- [ main] .s.b.c.e.j.JettyEmbeddedServletContainer : Jetty started on port(s) 8080 (http/1.1)
2018-09-26 16:55:33.409 INFO 158480 --- [ main] Application : Started Application in 2.319 seconds (JVM running for 2.824)
在实际开发中,我们会需要修改相关的端口号,因此我们需要将src/main/resources目录下面的application.properties文件中加入server.port配置指定端口号,如我的配置是,指定端口号为8888.这样我们访问项目的端口号就变了为8888端口了。
server.port=8888
其他:
Spring Boot 建议采用yml文件类型,因此我们尽量删除系统自动给创建的application.properties文件,然后创建一个application.yml文件。application.yml配置文件要求每个属性后面要有一个冒号和空格然后才能是参数值,而且根据属性的级别前面要加对应级别的空格或tab,如port是二级属性,前面就需要加一个空格或tab。配置信息如下:
server:
port: 8888
整体项目结构如下: