Spring Boot快速开发Web项目

我们以前使用Spring框架的时候，需要首先在pom文件中增加对相关的的依赖，然后新建Spring相关的xml文件，而且往往那些xml文件还不会少。然后继续使用tomcat或者jetty作为容器来运行这个工程。基本上每次创建一个新的项目都是这么一个流程，而我们有时候仅仅想快速的创建一个Spring web工程来测试一些东西，或者是希望能节省时间。

现在我们使用Spring Boot就可以快速的做到这些了。

1. 我们创建一个Maven工程，工程名字为spring-boot-helloworld，然后修改pom.xml文件：

<?xml version="1.0" encoding="UTF-8"?>
<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>net.mingyang</groupId>
    <artifactId>spring-boot-helloworld</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>spring-boot-helloworld</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.1.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>1.7</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2. 新建一个Controller来接受处理我们的请求：

package net.mingyang.spring_boot_helloworld;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

@SpringBootApplication
@Controller
public class SimpleController {

    @RequestMapping(value ="/hello", method = RequestMethod.GET)
    @ResponseBody
    public String hello(){
        return "hello world";
    }

    public static void main(String[] args) {
        SpringApplication.run(SimpleController.class, args);
    }
}

3. 执行SimleController中的main()方法：

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.4.1.RELEASE)

2016-10-18 08:43:46.946  INFO 4640 --- [           main] n.m.s.SimpleController                   : Starting SimpleController on D60601653 with PID 4640 (X:\dev\spring-test-suite\spring-boot-helloworld\target\classes started by lbin in X:\dev\spring-test-suite\spring-boot-helloworld)
2016-10-18 08:43:46.950  INFO 4640 --- [           main] n.m.s.SimpleController                   : No active profile set, falling back to default profiles: default
2016-10-18 08:43:47.238  INFO 4640 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@69cc1627: startup date [Tue Oct 18 08:43:47 CST 2016]; root of context hierarchy
2016-10-18 08:43:49.969  INFO 4640 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2016-10-18 08:43:49.983  INFO 4640 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2016-10-18 08:43:49.984  INFO 4640 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.5
2016-10-18 08:43:50.108  INFO 4640 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2016-10-18 08:43:50.109  INFO 4640 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2874 ms
2016-10-18 08:43:50.334  INFO 4640 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2016-10-18 08:43:50.340  INFO 4640 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2016-10-18 08:43:50.340  INFO 4640 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2016-10-18 08:43:50.340  INFO 4640 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2016-10-18 08:43:50.340  INFO 4640 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2016-10-18 08:43:50.766  INFO 4640 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@69cc1627: startup date [Tue Oct 18 08:43:47 CST 2016]; root of context hierarchy
2016-10-18 08:43:50.863  INFO 4640 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/hello],methods=[GET]}" onto public java.lang.String net.mingyang.spring_boot_helloworld.SimpleController.hello()
2016-10-18 08:43:50.868  INFO 4640 --- [           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)
2016-10-18 08:43:50.868  INFO 4640 --- [           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)
2016-10-18 08:43:50.912  INFO 4640 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2016-10-18 08:43:50.912  INFO 4640 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2016-10-18 08:43:51.029  INFO 4640 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2016-10-18 08:43:51.767  INFO 4640 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2016-10-18 08:43:51.878  INFO 4640 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2016-10-18 08:43:51.884  INFO 4640 --- [           main] n.m.s.SimpleController                   : Started SimpleController in 5.658 seconds (JVM running for 5.99)

查看日志可以发现默认使用的是tomcat，端口绑定在8080，访问：http://localhost:8080/hello，就可以看到我们代码中输出的字样了。

是不是很简单？