glossary

request flow

image.png

DispatcherServlet

• 根據(jù)pattern轉(zhuǎn)發(fā)request
• 把request 轉(zhuǎn)發(fā)到Spring MVC Controller
• 根據(jù)handler mappings 確定requests要經(jīng)過的component， mappings可以配置pattern
• 根據(jù)view resolver解析具體的view
• 啟動后創(chuàng)建Spring application context，加載配置的bean：
  • controllers
  • view resolvers
  • handler mappings

controller

• 指定渲染的view

model

• 產(chǎn)生需要返回客戶端的數(shù)據(jù)

view

• render the output

ContextLoaderListener

加載middle-tier和data-tier components

配置mvc

spring web application 中一般會創(chuàng)建兩個application context：

• DispatcherServlet
• ContextLoaderListener

configuring dispatcherservlet

AbstractAnnotationConfigDispatcherServletInitializer（前提條件web服務(wù)器必須支持Servlet 3.0，Apache Tomcat 7以上） JavaConfig：

• getServletMappings()： 指定map的path
• protected Class<?>[] getServletConfigClasses()： 指定DispatcherServlet 創(chuàng)建的application context 使用的配置類
• protected Class<?>[] getRootConfigClasses()： 創(chuàng)建的ContextLoaderListener application context 使用的配置類

enabling spring mvc

1. DispatcherServlet 配置：

package spittr.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.
DefaultServletHandlerConfigurer; import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.
                                      WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.
                                         InternalResourceViewResolver;
@Configuration
@EnableWebMvc  
@ComponentScan("spitter.web")
public class WebConfig
       extends WebMvcConfigurerAdapter {
  @Bean
  public ViewResolver viewResolver() {
    InternalResourceViewResolver resolver =
            new InternalResourceViewResolver();
    resolver.setPrefix("/WEB-INF/views/");
    resolver.setSuffix(".jsp");
    resolver.setExposeContextBeansAsAttributes(true);
    return resolver;
}
  @Override
  public void configureDefaultServletHandling(
        DefaultServletHandlerConfigurer configurer) {
    configurer.enable();
} }

2. ContextLoaderListener

package spittr.config;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ComponentScan.Filter; import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
@Configuration
@ComponentScan(basePackages={"spitter"},
    excludeFilters={
        @Filter(type=FilterType.ANNOTATION, value=EnableWebMvc.class)
    })
public class RootConfig {
}