如何使用Spring's Java Configuration

如何使用Spring's Java Configuration

这是一个非常基础的在Spring-MVC中使用JavaConfig来编写helloworld web程序的例子.
第一部分我来为我们的web-app创建一个配置类（configuaration class）。下面这个就是我们即将使用的configuaration class案例：
@Configuration
@EnableWebMvc
@ComponentScan(basePackages = {"com.johnathanmsmith.mvc.web"})
public class WebMVCConfig extends WebMvcConfigurerAdapter
{

private static final Logger logger = LoggerFactory.getLogger(WebMVCConfig.class);

@Bean
public ViewResolver resolver()
{
UrlBasedViewResolver url = new UrlBasedViewResolver();
url.setPrefix("/views/");
url.setViewClass(JstlView.class);
url.setSuffix(".jsp");
return url;
}

@Override
public void addResourceHandlers(ResourceHandlerRegistry registry)
{
logger.debug("setting up resource handlers");
registry.addResourceHandler("/resources/").addResourceLocations("/resources/**");
}

@Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer)
{
logger.debug("configureDefaultServletHandling");
configurer.enable();
}

@Bean
public SimpleMappingExceptionResolver simpleMappingExceptionResolver()
{
SimpleMappingExceptionResolver b = new SimpleMappingExceptionResolver();

Properties mappings = new Properties();
mappings.put("org.springframework.web.servlet.PageNotFound", "p404");
mappings.put("org.springframework.dao.DataAccessException", "dataAccessFailure");
mappings.put("org.springframework.transaction.TransactionException", "dataAccessFailure");
b.setExceptionMappings(mappings);
return b;
}
}