1. 设置spring boot的parent
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.2.RELEASE</version> </parent>
说明：Spring boot的项目必须要将parent设置为spring boot的parent，该parent包含了大量默认的配置，大大简化了我们的开发。
2. 导入spring boot的web支持
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency>
3. 添加Spring boot的插件
<plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin>
最终的pom.xml：
<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>cn.qiaoliqiang</groupId> <artifactId>spring-boot</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>war</packaging> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.2.RELEASE</version> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>4.3.7.RELEASE</version> </dependency> <!-- 连接池 --> <dependency> <groupId>com.jolbox</groupId> <artifactId>bonecp-spring</artifactId> <version>0.8.0.RELEASE</version> </dependency> </dependencies> <build> <finalName>${project.artifactId}</finalName> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> <!-- 资源文件拷贝插件 --> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-resources-plugin</artifactId> <configuration> <encoding>UTF-8</encoding> </configuration> </plugin> <!-- java编译插件 --> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.7</source> <target>1.7</target> <encoding>UTF-8</encoding> </configuration> </plugin> </plugins> <pluginManagement> <plugins> <!-- 配置Tomcat插件 --> <plugin> <groupId>org.apache.tomcat.maven</groupId> <artifactId>tomcat7-maven-plugin</artifactId> <version>2.2</version> </plugin> </plugins> </pluginManagement> </build> </project>
4. 编写第一个Spring Boot的应用
@Controller
@SpringBootApplication
@Configuration
public class HelloApplication {
@RequestMapping("hello")
@ResponseBody
public String hello(){
return "hello world！";
}
public static void main(String[] args) {
SpringApplication.run(HelloApplication.class, args);
}
}
代码说明：
1、@SpringBootApplication：Spring Boot项目的核心注解，主要目的是开启自动配置。；
2、@Configuration：这是一个配置Spring的配置类；
3、@Controller：标明这是一个SpringMVC的Controller控制器；
4、main方法：在main方法中启动一个应用，即：这个应用的入口；
5. 启动应用
在Spring Boot项目中，启动的方式有两种，一种是直接run Java Application另外一种是通过Spring Boot的Maven插件运行。
第一种：
结果:
. ____ _ __ _ _
/\ / ___'_ __ _ _(_)_ __ __ _
( ( )\___ | '_ | '_| | '_ / _` |
\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v1.5.2.RELEASE)
2018-01-11 16:54:36.745 INFO 882716 --- [ main] cn.qlq.springboot.HelloApplication : Starting HelloApplication on root with PID 882716 (E:MavenEclipseWorkspacespring-boot argetclasses started by liqiang in E:MavenEclipseWorkspacespring-boot)
2018-01-11 16:54:36.750 INFO 882716 --- [ main] cn.qlq.springboot.HelloApplication : No active profile set, falling back to default profiles: default
2018-01-11 16:54:36.872 INFO 882716 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@67dd2285: startup date [Thu Jan 11 16:54:36 CST 2018]; root of context hierarchy
2018-01-11 16:54:40.517 INFO 882716 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2018-01-11 16:54:40.678 INFO 882716 --- [ main] o.apache.catalina.core.StandardService : Starting service Tomcat
2018-01-11 16:54:40.680 INFO 882716 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.11
2018-01-11 16:54:40.998 INFO 882716 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2018-01-11 16:54:40.999 INFO 882716 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 4131 ms
2018-01-11 16:54:41.365 INFO 882716 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/]
2018-01-11 16:54:41.372 INFO 882716 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-01-11 16:54:41.373 INFO 882716 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2018-01-11 16:54:41.373 INFO 882716 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2018-01-11 16:54:41.373 INFO 882716 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2018-01-11 16:54:42.097 INFO 882716 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@67dd2285: startup date [Thu Jan 11 16:54:36 CST 2018]; root of context hierarchy
2018-01-11 16:54:42.240 INFO 882716 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/hello]}" onto public java.lang.String cn.qlq.springboot.HelloApplication.hello()
2018-01-11 16:54:42.250 INFO 882716 --- [ 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)
2018-01-11 16:54:42.251 INFO 882716 --- [ 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)
2018-01-11 16:54:42.351 INFO 882716 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-01-11 16:54:42.351 INFO 882716 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-01-11 16:54:42.481 INFO 882716 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-01-11 16:54:43.241 INFO 882716 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2018-01-11 16:54:43.414 INFO 882716 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2018-01-11 16:54:43.429 INFO 882716 --- [ main] cn.qlq.springboot.HelloApplication : Started HelloApplication in 8.809 seconds (JVM running for 9.52)
2018-01-11 17:04:05.722 INFO 882716 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring FrameworkServlet 'dispatcherServlet'
2018-01-11 17:04:05.722 INFO 882716 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization started
2018-01-11 17:04:05.804 INFO 882716 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization completed in 82 ms
访问:
第二种：以spring-boot插件的方式运行:
(1)添加一个maven常用命令
（2）运行上面建的maven命令:
结果与上面一样
看到如下信息就说明启动成功了：
2018-01-11 18:01:42.242 INFO 1021040 --- [ main] cn.qlq.springboot.HelloApplication : Started HelloApplication in 6.845 seconds (JVM running for 16.07)
测试:
