SPRING IN ACTION 第4版笔记-第五章Building Spring web applications-001-SpringMVC介绍

一、

 

二、用Java文件配置web application

1.

package spittr.config;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

import spittr.web.WebConfig;

public class SpitterWebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
  
  @Override
  protected Class<?>[] getRootConfigClasses() {
    return new Class<?>[] { RootConfig.class };
  }

  @Override
  protected Class<?>[] getServletConfigClasses() {
    //Specify configuration class
    return new Class<?>[] { WebConfig.class };
  }

  @Override
  protected String[] getServletMappings() {
    //Map DispatcherServlet to "/"
    return new String[] { "/" };
  }

}

(1)值得注意的是SpitterWebInitializer继承了AbstractAnnotationConfigDispatcherServletInitializer，所以在Servlet3.1以上的容器中，会自动将此类作为DispatcherServlet和Spring Application Context的配置文件

从Servlect3.0开始，窗器会在classpath中寻找实现javax.servlet.ServletContainerInitializer的类作为配置文件，而Spring提供了实现SpringServletContainerInitializer、WebApplicationInitializer、AbstractAnnotationConfigDispatcherServletInitializer

(2)在Spring web application通常有两种context：Dispactcherservlet、ContextLoaderListener

Dispactcherservlet用来装载springmvc相关组件，如controller、view resolvers、handler mappings,ContextLoaderListener是装载应用的其他组件，通常是中间层和后台打交道的组件，如service、dao。 上述配置文件通过getServletConfigClasses()以返回的java配置文件来定义Dispatcherservlet，用getRootConfigClasses()以返回的配置文件定义ContextLoaderListener，其实就是相当于以前的web.xml配置

2.

package spittr.web;

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.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan("spittr.web")
public class WebConfig extends WebMvcConfigurerAdapter {

  @Bean
  public ViewResolver viewResolver() {
    InternalResourceViewResolver resolver = new InternalResourceViewResolver();
    resolver.setPrefix("/WEB-INF/views/");
    resolver.setSuffix(".jsp");
    return resolver;
  }
  
  @Override
  public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
    //Configure static content handling
    configurer.enable();    
    //configurer.enable();是you’re asking  DispatcherServlet to forward
    //requests for static resources to the servlet container’s default servlet and not to try to
    //handle them itself.
  }
  
  @Override
  public void addResourceHandlers(ResourceHandlerRegistry registry) {
    // TODO Auto-generated method stub
    super.addResourceHandlers(registry);
  }

}

在xml中是用 <mvc:annotation-driven>

3.

package spittr.config;

import java.util.regex.Pattern;

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.context.annotation.Import;
import org.springframework.core.type.filter.RegexPatternTypeFilter;

import spittr.config.RootConfig.WebPackage;

@Configuration
@Import(DataConfig.class)
@ComponentScan(basePackages={"spittr"}, 
    excludeFilters={
        @Filter(type=FilterType.CUSTOM, value=WebPackage.class)
    })
public class RootConfig {
  public static class WebPackage extends RegexPatternTypeFilter {
    public WebPackage() {
      super(Pattern.compile("spittr\.web"));
    }    
  }
}

4.

package spittr.config;

import javax.sql.DataSource;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.core.JdbcOperations;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseBuilder;
import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType;

@Configuration
public class DataConfig {

  @Bean
  public DataSource dataSource() {
    return new EmbeddedDatabaseBuilder()
            .setType(EmbeddedDatabaseType.H2)
            .addScript("schema.sql")
            .build();
  }
  
  @Bean
  public JdbcOperations jdbcTemplate(DataSource dataSource) {
    return new JdbcTemplate(dataSource);
  }

}

5.