Spring 3.1 Java Configuration - @Autowired、@Configuration和@Profile挑战

Question

我正在尝试Spring3.1和Servlet3.0，我对新的Java配置选项以及Spring配置文件的使用非常感兴趣，我遇到了一个挑战。尽管我在网上看到的所有示例看起来都像是一个用@Configuration注释的类可以将其他对象@Autowired连接到其中，但我看到的是，只有在生成了@Configuration类中的一些bean之后，才会发生自动装配。

这是我的初始化器：

public class SpringMvcInitializer implements WebApplicationInitializer {

private static org.apache.log4j.Logger log= Logger.getLogger(SpringMvcInitializer.class);

@Override
public void onStartup(ServletContext servletContext) throws ServletException {
    // Create the 'root' Spring application context
    AnnotationConfigWebApplicationContext rootContext  = new AnnotationConfigWebApplicationContext();
    rootContext.scan("org.jc.config");
    servletContext.addListener(new ContextLoaderListener(rootContext));

    // Secures the application
    servletContext.addFilter("securityFilter", new DelegatingFilterProxy("springSecurityFilterChain"))
        .addMappingForUrlPatterns(null, false, "/*");       

    ServletRegistration.Dynamic appServlet =
            servletContext.addServlet("appServlet", new DispatcherServlet(new GenericWebApplicationContext()));
    appServlet.setLoadOnStartup(1); 

    appServlet.addMapping("/");

    log.info("Mvc Initializer starting");
}

我的Web配置

@Configuration
@EnableWebMvc
@ComponentScan(basePackages="org.jc" )
public class WebConfig extends WebMvcConfigurerAdapter {

@Bean
public InternalResourceViewResolver configureInternalResourceViewResolver() {
    InternalResourceViewResolver resolver = new InternalResourceViewResolver();
    resolver.setPrefix("/WEB-INF/");
    resolver.setSuffix(".jsp");
    return resolver;
}

@Override
public void configureResourceHandling(ResourceConfigurer configurer) {
    configurer.addPathMapping("/resources/**");
    configurer.addResourceLocation("/resources/");
}

我的JPA配置类

@Configuration
public class JpaConfig {
private static Logger logger = Logger.getLogger(JpaConfig.class);

private AppEnvironmentI appEnvironment;

@Autowired
public void setAppEnvironment(AppEnvironmentI appEnvironment) {
    this.appEnvironment = appEnvironment;
    checkAppEnv("setAppEnvironment");
}

@Bean
public AppUser globalUser(){
    checkAppEnv("globalUser entry");
    AppUser appUser = new AppUser();
    checkAppEnv("globalUser exit");
    return appUser;
}

@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory(){
    checkAppEnv("entityManagerFactory entry");
    LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean ();
    emf.setDataSource(dataSource());
    emf.setJpaVendorAdapter(this.jpaAdapter());
    emf.setPersistenceUnitName("JcEntities2");
    checkAppEnv("entityManagerFactory exit");
    return emf;
}

@Bean
public DataSource dataSource(){
    checkAppEnv("dataSource entry");
    DriverManagerDataSource ds = new DriverManagerDataSource();
    ds.setDriverClassName("org.apache.derby.jdbc.EmbeddedDriver");
    ds.setUrl("jdbc:derby://localhost:1527/JcTestDb");
    ds.setUsername("jc");
    ds.setPassword("pwd");
    checkAppEnv("dataSource exit");
    return ds;
}

@Bean
public JpaVendorAdapter jpaAdapter() {
    checkAppEnv("jpaAdapter entry");
    HibernateJpaVendorAdapter hibernateJpaVendorAdapter = new HibernateJpaVendorAdapter();
    hibernateJpaVendorAdapter.setShowSql(true);
    hibernateJpaVendorAdapter.setDatabase(Database.DERBY);
    checkAppEnv("jpaAdapter exit");
    return hibernateJpaVendorAdapter;
}

@Bean
public PlatformTransactionManager transactionManager() {
    checkAppEnv("transactionManager entry and exit");
    return new JpaTransactionManager( entityManagerFactory().getObject() );
}

private void checkAppEnv(String _method){
    if(this.appEnvironment == null){
        logger.info(_method + " - App Environment is null!!!!");
    }else{
        logger.info(_method + " - App Environment JpaConfig = " + appEnvironment.externalPropertiesFile().getPropertyValue("environment"));
    }
}

我的配置文件类

@Configuration
@Profile("local")
public class AppEnvironmentLocal implements AppEnvironmentI{
private static Logger logger = Logger.getLogger(AppEnvironmentLocal.class);

@Bean
public AppEnvironment externalPropertiesFile(){
    logger.info("Fetching properties file for LOCAL environment");
    Properties props = FileUtilsJc.getPropertiesFromFlatFile("C:\\AppConf\\JcConf\\JcConfLocal.properties");
    AppEnvironment exf = new AppEnvironment(props);
    return exf;
}
}

记录器输出:看起来Spring3.1在AppEnvironment注入类之前首先尝试创建实体管理器工厂bean。因此，它创建除全局用户(我放入其中进行测试的虚拟bean )和事务管理器之外的所有bean，注入AppEnvironment，然后创建全局用户和事务管理器bean。

任何想法都非常感谢！

01-Sep-2011 10:20:55  INFO Mvc Initializer starting
01-Sep-2011 10:20:55  INFO entityManagerFactory entry - App Environment is null!!!!
01-Sep-2011 10:20:55  INFO dataSource entry - App Environment is null!!!!
01-Sep-2011 10:20:55  INFO dataSource exit - App Environment is null!!!!
01-Sep-2011 10:20:55  INFO jpaAdapter entry - App Environment is null!!!!
01-Sep-2011 10:20:55  INFO jpaAdapter exit - App Environment is null!!!!
01-Sep-2011 10:20:55  INFO entityManagerFactory exit - App Environment is null!!!!
01-Sep-2011 10:20:55  INFO Fetching properties file for LOCAL environment
01-Sep-2011 10:20:55  INFO setAppEnvironment - App Environment JpaConfig = LOCAL

下面是我用来连接它的示例代码的URL：

http://blog.springsource.com/2011/02/14/spring-3-1-m1-introducing-profile/

我发现在Spring3.1之前的文档中，有必要将@AnnotationDrivenConfig注释添加到您的可注入类中，才能让@Autowired工作，但这在Spring 3.1中已被弃用。我发现许多帖子都在寻找该注释，但没有解决何时注入配置对象的问题！

Answer 1

据我所知，@Configuration bean是在非配置bean之前构造的，用@Bean标记的方法在返回时会生成还不是bean的对象；构造bean的顺序是未定义的(除了一些特殊的bean类型；标准属性文件加载器很早就会被调用，这样它们发现的值就可以用来设置@Configuration bean)。直接调用bean方法是不可取的；让Spring为您做，因为它在@Bean方法返回后连接属性。