java – Spring引导 – 环境@Autowired抛出NullPointerException

在我的一个配置文件我试图@Autowire环境,但失败与NullPointerException.

这是我到目前为止

Application.java

@EnableAutoConfiguration
@Configuration
@ComponentScan
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class,args);
    }
}

JpaConfig.java在哪里我试图@Autowire环境

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = "com.ui.persistence.repository")
public class JpaConfig {
    private static final String DATABASE_DRIVER = "db.driver";
    private static final String DATABASE_PASSWORD = "db.password";
    private static final String DATABASE_URL = "db.url";
    private static final String DATABASE_USERNAME = "db.username";
    private static final String HIBERNATE_DIALECT = "hibernate.dialect";
    private static final String HIBERNATE_SHOW_sql = "hibernate.show_sql";
    private static final String ENTITYMANAGER_PACKAGES_TO_SCAN 
        = "entitymanager.packages.to.scan";

    @Autowired
    private Environment env;

    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(env.getProperty(DATABASE_DRIVER));
        dataSource.setUrl(env.getProperty(DATABASE_URL));
        dataSource.setUsername(env.getProperty(DATABASE_USERNAME));
        dataSource.setPassword(env.getProperty(DATABASE_PASSWORD));
        return dataSource;
    }

    @Bean
    public LocalContainerEntityManagerfactorybean entityManagerFactory() {
        LocalContainerEntityManagerfactorybean entityManagerfactorybean 
                = new LocalContainerEntityManagerfactorybean();
        entityManagerfactorybean.setDataSource(dataSource());
        entityManagerfactorybean.setPersistenceProviderClass(
                HibernatePersistence.class);
        entityManagerfactorybean.setPackagesToScan(
                env.getProperty(ENTITYMANAGER_PACKAGES_TO_SCAN));
        entityManagerfactorybean.setJpaProperties(hibernateProperties());
        return entityManagerfactorybean;
    }
}

我正在尝试加载属性文件中配置的数据库属性.但是,环境不会被注入,并且代码与NullPointerException失败.我在XML文件中没有任何配置.

对于属性文件,我以这种方式配置了PropertySourcesPlaceholderConfigurer：

@Configuration
@PropertySource("classpath:database.properties")
public class PropertyConfig {
    @Bean
    public static PropertySourcesPlaceholderConfigurer propertyPlaceHolderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }
}

我已经尝试交换@Autowired,@Resource和@Inject,但迄今没有任何工作.会感谢任何帮助.谢谢.