使用Spring Boot來加速Java web項目的開發

我想，現在企業級的Java web項目應該或多或少都會使用到Spring框架的。

 

回首我們以前使用Spring框架的時候，我們需要首先在（如果你使用Maven的話）pom文件中增加對相關的的依賴（使用gradle來構建的話基本也一樣）然后新建Spring相關的xml文件，而且往往那些xml文件還不會少。然后繼續使用tomcat或者jetty作為容器來運行這個工程。基本上每次創建一個新的項目都是這么一個流程，而我們有時候僅僅想快速的創建一個Spring web工程來測試一些東西，或者是希望能節省時間。

 

現在我們使用Spring Boot就可以快速的做到這些了。

 

我們先來看一個非常簡單的使用Spring boot的例子吧：

 

1.　　我們創建一個Maven工程，假定工程名字為spring-boot，然后我們在pom.xml文件中加入依賴：

      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-web</artifactId>
          <version>1.0.2.RELEASE</version>
      </dependency>

2.　　新建一個Controller來接受處理我們的請求：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
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;

/**
 * Created by wenchao.ren on 2014/4/26.
 */
@Controller
@EnableAutoConfiguration
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);
    }
}

相信大家已經看到了這個Controller有一個main方法，不要急，我們直接運行這個main方法：

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.0.2.RELEASE)

2014-04-26 22:54:40.985  INFO 7236 --- [           main] c.r.spring.boot.SimpleController         : Starting SimpleController on rollen with PID 7236 (D:\workspace\GitHub\SpringDemo\spring-boot\target\classes started by wenchao.ren in D:\workspace\GitHub\SpringDemo\spring-boot)
2014-04-26 22:54:41.008  INFO 7236 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@50de0926: startup date [Sat Apr 26 22:54:41 CST 2014]; root of context hierarchy
2014-04-26 22:54:41.583  INFO 7236 --- [           main] .t.TomcatEmbeddedServletContainerFactory : Server initialized with port: 8080
2014-04-26 22:54:41.706  INFO 7236 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2014-04-26 22:54:41.706  INFO 7236 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/7.0.52
2014-04-26 22:54:41.785  INFO 7236 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2014-04-26 22:54:41.785  INFO 7236 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 779 ms
2014-04-26 22:54:42.055  INFO 7236 --- [ost-startStop-1] o.s.b.c.e.ServletRegistrationBean        : Mapping servlet: 'dispatcherServlet' to [/]
2014-04-26 22:54:42.057  INFO 7236 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean  : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2014-04-26 22:54:42.289  INFO 7236 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2014-04-26 22:54:42.368  INFO 7236 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/hello],methods=[GET],params=[],headers=[],consumes=[],produces=[],custom=[]}" onto public java.lang.String com.rollenholt.spring.boot.SimpleController.hello()
2014-04-26 22:54:42.376  INFO 7236 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2014-04-26 22:54:42.377  INFO 7236 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2014-04-26 22:54:42.447  INFO 7236 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2014-04-26 22:54:42.459  INFO 7236 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080/http
2014-04-26 22:54:42.460  INFO 7236 --- [           main] c.r.spring.boot.SimpleController         : Started SimpleController in 1.675 seconds (JVM running for 1.944)
2014-04-26 22:54:54.963  INFO 7236 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
2014-04-26 22:54:54.963  INFO 7236 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
2014-04-26 22:54:54.971  INFO 7236 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 8 ms

會產生上面的輸出，查看日志可以發現默認使用的是tomcat，端口綁定在8080，現在讓我們來訪問：http://localhost:8080/hello

就可以看到我們代碼中輸出的字樣：hello world了。

回首這個過程，是不是相比於以前快速了許多呢

 

參考資料：

1.　　Spring Boot Reference Guide