Spring:@Autowired 用于 POJO，不由 Spring 管理

Question

这个问题在这里已经有了答案:





Why is my Spring @Autowired field null?

(21 个回答)


7年前关闭。




我使用@Autowired 在 POJO 中注入(inject)一些服务。这些服务被注册为 Bean。

如果 POJO 由 Spring 管理(它也在 Spring Config 上注册为 Bean)，那么我对注入(inject)服务没有问题。

但是，如果我创建了“经典”POJO 并通过"new"创建它，则不会注入(inject)任何服务。

我的问题:是否可以配置 Spring 来实现 @Autowired 注入(inject)？

我使用由 JavaConfig 配置的 Spring 4.0.3:

====

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.core.Ordered;
import org.springframework.http.MediaType;
import org.springframework.security.oauth2.provider.ClientDetailsService;
import org.springframework.security.oauth2.provider.approval.ApprovalStore;
import org.springframework.security.oauth2.provider.token.ConsumerTokenServices;
import org.springframework.security.oauth2.provider.token.TokenStore;
import org.springframework.web.accept.ContentNegotiationManagerFactoryBean;
import org.springframework.web.servlet.View;
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.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.ContentNegotiatingViewResolver;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.json.MappingJackson2JsonView;

import com.tr.oauth.service.PhotoInfo;
import com.tr.oauth.service.PhotoService;
import com.tr.oauth.service.impl.PhotoServiceImpl;
import com.tr.oauth.service.oauth.ExtendedApprovalStoreUserApprovalHandler;

@Configuration
@EnableWebMvc
public class WebMvcConfig extends WebMvcConfigurerAdapter {

    @Bean
    public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }

   @Bean
    public ContentNegotiatingViewResolver contentViewResolver() throws Exception {
        ContentNegotiationManagerFactoryBean contentNegotiationManager = new ContentNegotiationManagerFactoryBean();
        contentNegotiationManager.addMediaType("json", MediaType.APPLICATION_JSON);

        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
        viewResolver.setPrefix("/WEB-INF/jsp/");
        viewResolver.setSuffix(".jsp");

        MappingJackson2JsonView defaultView = new MappingJackson2JsonView();
        defaultView.setExtractValueFromSingleKeyModel(true);

        ContentNegotiatingViewResolver contentViewResolver = new ContentNegotiatingViewResolver();
        contentViewResolver.setContentNegotiationManager(contentNegotiationManager.getObject());
        contentViewResolver.setViewResolvers(Arrays.<ViewResolver>asList(viewResolver));
        contentViewResolver.setDefaultViews(Arrays.<View>asList(defaultView));
        return contentViewResolver;
    }

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/login").setViewName("login");
        registry.setOrder(Ordered.HIGHEST_PRECEDENCE);
    }

    @Bean
    public PhotoServiceUserController photoServiceUserController(PhotoService photoService) {
       PhotoServiceUserController photoServiceUserController = new PhotoServiceUserController();
       return photoServiceUserController;
    }

    @Bean
    public PhotoController photoController(PhotoService photoService) {
        PhotoController photoController = new PhotoController();
        photoController.setPhotoService(photoService);
        return photoController;
    }

    @Bean
    public AccessConfirmationController accessConfirmationController(ClientDetailsService clientDetailsService, ApprovalStore approvalStore) {
        AccessConfirmationController accessConfirmationController = new AccessConfirmationController();
        accessConfirmationController.setClientDetailsService(clientDetailsService);
        accessConfirmationController.setApprovalStore(approvalStore);
        return accessConfirmationController;
    }

    @Bean
    public PhotoServiceImpl photoServices() {
        List<PhotoInfo> photos = new ArrayList<PhotoInfo>();
        photos.add(createPhoto("1", "marissa"));
        photos.add(createPhoto("2", "paul"));
        photos.add(createPhoto("3", "marissa"));
        photos.add(createPhoto("4", "paul"));
        photos.add(createPhoto("5", "marissa"));
        photos.add(createPhoto("6", "paul"));

        PhotoServiceImpl photoServices = new PhotoServiceImpl();
        photoServices.setPhotos(photos);
        return photoServices;
    }


    @Bean
    public AdminController adminController(TokenStore tokenStore, ConsumerTokenServices tokenServices,
            ExtendedApprovalStoreUserApprovalHandler userApprovalHandler) {
        AdminController adminController = new AdminController();
        adminController.setTokenStore(tokenStore);
        adminController.setTokenServices(tokenServices);
        adminController.setUserApprovalHandler(userApprovalHandler);
        return adminController;
    }

   private PhotoInfo createPhoto(String id, String userId) {
        PhotoInfo photo = new PhotoInfo();
        photo.setId(id);
        photo.setName("photo" + id + ".jpg");
        photo.setUserId(userId);
        photo.setResourceURL("/impl/resources/" + photo.getName());
        return photo;
    }

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


-----------

import javax.servlet.ServletContext;
import javax.servlet.ServletException;

import org.springframework.util.ClassUtils;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.filter.DelegatingFilterProxy;
import org.springframework.web.servlet.support.AbstractDispatcherServletInitializer;

/**
 * @author Dave Syer
 * 
 */
public class ServletInitializer extends AbstractDispatcherServletInitializer {

    @Override
    protected WebApplicationContext createServletApplicationContext() {
        AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
        context.scan(ClassUtils.getPackageName(getClass()));
        return context;
    }

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

    @Override
    protected WebApplicationContext createRootApplicationContext() {
        return null;
    }

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        super.onStartup(servletContext);
        DelegatingFilterProxy filter = new DelegatingFilterProxy("springSecurityFilterChain");
        filter.setContextAttribute("org.springframework.web.servlet.FrameworkServlet.CONTEXT.dispatcher");
        servletContext.addFilter("springSecurityFilterChain", filter).addMappingForUrlPatterns(null, false, "/*");
    }

}

Answer 1

是的，@Configurable 可以做到这一点。注释和一些字节码魔术。

Oliver Gierke 背后的人 Spring Data在这个主题上创建了一篇不错的博客文章:
http://olivergierke.de/2009/05/using-springs-configurable-in-three-easy-steps/
http://aredko.blogspot.de/2011/02/using-configurable-in-spring-framework.html

在 SO 上还有一个没有接受答案的问题:
Spring autowiring using @Configurable