java - 从另一个 WAR 继承 Spring 配置

Question

我们在 Eclipse 中有一个名为“Framework”的 SpringMVC 项目和一个必须从“Framework”配置继承的“新项目”。

两个 Spring 项目均未使用 .xml 配置文件。

“框架”包含所有业务类、数据源配置和 ContextListener 默认行为，我们不想在每次启动新项目时都重写它们。

“框架”作为 Maven 覆盖层加载到第二个项目中。

正如您在下面看到的，这是一个非常基本的 SpringMVC 配置示例。

框架

-- main
    -- java
        -- config
            - AppConfig.class (implements WebMvcConfigurer)
            - AppInit.class (implements WebApplicationInitializer)

AppConfig.class

@EnableAspectJAutoProxy
@EnableWebMvc
@ComponentScan(basePackages="main.java")
public class AppConfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new ControllerLoggingInterceptor()).addPathPatterns("/*");
    }
    @Bean
    public ViewResolver getViewResolver(){
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/jsp/");
        resolver.setSuffix(".jsp");
        return resolver;
    }
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/resources/**").addResourceLocations("/resources/");
        registry.addResourceHandler("/images/**").addResourceLocations("/resources/images");
    }
    @Bean
    public ReloadableResourceBundleMessageSource messageSource() {
        ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
        messageSource.setBasenames("classpath:messages","classpath:/framework/messages");
        return messageSource;
    }
    @Bean
    public javax.validation.Validator localValidatorFactoryBean() {
        return new LocalValidatorFactoryBean();
    }
    @Bean
    public MultipartResolver multipartResolver() {
        CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver();
        multipartResolver.setMaxUploadSize(838860800);
        return multipartResolver;
    }
}

AppInit.class

public class AppInit implements WebApplicationInitializer {
    @Autowired
    MapperInfosDB mapperUserBD;
    @Override
    public void onStartup(ServletContext container) {
        AnnotationConfigWebApplicationContext appContext = new AnnotationConfigWebApplicationContext();
        appContext.register(AppConfig.class);
        container.addListener(new ContextLoaderListener(appContext));
        AnnotationConfigWebApplicationContext dispatcherContext =
        new AnnotationConfigWebApplicationContext();
        dispatcherContext.register(AppConfig.class);
        ServletRegistration.Dynamic dispatcher =
        container.addServlet("dispatcher", new DispatcherServlet(dispatcherContext));
        dispatcher.addMapping("/");
        FilterRegistration.Dynamic fr = container.addFilter("encodingFilter", new CharacterEncodingFilter());
        fr.setInitParameter("encoding", "UTF-8");
        fr.setInitParameter("forceEncoding", "true");
        fr.addMappingForUrlPatterns(null, false, "/*");
        fr = container.addFilter("RequestLoggingFilter", new RequestLoggingFilter());
        fr.addMappingForUrlPatterns(null, true, "/*");
    }
}

在第二个项目中，我成功导入“Framework”应用程序上下文，但尚未成功导入 WebApplicationContext，因为它会导致 NullPointerException。

新项目

-- main
    -- java
        -- config
            - ApplicationContextConfiguration.class (extends ContextLoaderListener implements WebMvcConfigurer)
            - WebConfiguration.class (implements WebApplicationInitializer)

ApplicationContextConfiguration.class

@Configuration
@EnableWebMvc
@EnableAspectJAutoProxy
public class ApplicationContextConfiguration extends ContextLoaderListener implements WebMvcConfigurer {
    @Override
    protected ApplicationContext loadParentContext(ServletContext servletContext) {
        ApplicationContext ac = new AnnotationConfigApplicationContext(AppConfig.class);
        // Do some stuff on applicationContext inherited from Framework
        return ac;
    }
}

WebConfiguration.class

@Configuration
public class WebConfiguration implements WebApplicationInitializer {
        private static final String[] BASE_PACKAGE = { "main.java", "new.project.packages" };
    @Override
    public void onStartup(ServletContext container) {
        AnnotationConfigWebApplicationContext dispatcherContext = new AnnotationConfigWebApplicationContext();
        dispatcherContext.scan(BASE_PACKAGE);
        dispatcherContext.register(AppConfig.class);
        dispatcherContext.register(AppInit.class);
        ServletRegistration.Dynamic dispatcher = container.addServlet("dispatcher", new DispatcherServlet(dispatcherContext));
        dispatcher.addMapping("/");
        dispatcher.setLoadOnStartup(1);
        FilterRegistration.Dynamic fr =  container.addFilter("encodingFilter", new CharacterEncodingFilter());
        fr.setInitParameter("encoding", "UTF-8");
        fr.setInitParameter("forceEncoding", "true");
        fr.addMappingForUrlPatterns(null, false, "/*");
        fr.addMappingForUrlPatterns(null, true, "/*");
    }
}

StackTrace 显示:

Caused by: java.lang.NullPointerException
    at main.java.config.AppInit.onStartup(AppInit.java:50)
    at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:172)

Answer 1

您必须在当前配置中导入配置类:

import org.springframework.context.annotation.*;

@EnableAspectJAutoProxy
@EnableWebMvc
@ComponentScan(basePackages="main.java")
@Import({WebConfiguration.class, ApplicationContextConfiguration.class })
public class AppConfig implements WebMvcConfigurer {
//Your current configuration
}