spring4.x 零配置搭建重要的配置類

spring4.x以後,實作了零配置.其實就是把相關的配置檔案變成了配置類.以前的application.xml變成了

@Configuration

 
 
  @EnableWebMvc

 
 
  @ComponentScan
  (
  "com.youxiduo.annotation"
  )

 
 
  public 
  class 
  AnnoConfig 
  {

 
 
  }
       

@Configuration 聲明這個類是配置類

@ComponentScan 對所有component(元件)的掃描,加載

@EnableWebMvc 開啟對webMvc的支援

上面隻是spring容器的配置類,那麼如何接受到前台的請求呢,這個就要實作spring對web.xml的實作

public 
  class 
  WebInitializer 
  implements 
  WebApplicationInitializer 
  {

 
     
  @Override

 
     
  public 
  void 
  onStartup
  (
  ServletContext 
  servletContext
  ) 
  throws 
  ServletException 
  {

 
         
  AnnotationConfigWebApplicationContext 
  ctx 
  = 
  new 
  AnnotationConfigWebApplicationContext
  ();

 
         
  ctx
  .
  register
  (
  AnnoConfig
  .
  class
  );

 
         
  ctx
  .
  setServletContext
  (
  servletContext
  );//建立WebApplicationContext,注冊配置類,并将其和目前的servletContext關聯

 
 

 
 
  	//注冊sprigmvc的DispatcherServlet
 
        
  ServletRegistration
  .
  Dynamic 
  servlet 
  = 
  servletContext
  .
  addServlet
  (
  "dispatcher"
  ,
  new 
  DispatcherServlet
  (
  ctx
  ));

 
         
  servlet
  .
  addMapping
  (
  "/"
  );

 
         
  servlet
  .
  setLoadOnStartup
  (
  1
  );

 
     
  }

 
 
  }
       

WebApplicationInitializer 是spring提供用來配置Servlet3.0+配置接口,進而實作了替代web.xml的位置.實作接口将自動被SpringServletContainerInitializer（用來擷取Servlet3.0容器的）擷取到.

需要用到的兩個jar檔案

<dependency>

 
 
              <groupId>javax</groupId>

 
 
              <artifactId>javaee-web-api</artifactId>

 
 
              <version>7.0</version>

 
 
              <scope>provided</scope>

 
 
          </dependency>

 
 
          <!--Spring MVC -->

 
 
          <dependency>

 
 
              <groupId>org.springframework</groupId>

 
 
              <artifactId>spring-webmvc</artifactId>

 
 
              <version>4.3.4.RELEASE</version>

 
 
          </dependency>