@Value注释未正确设置

Question

这是我的应用程序:

public static void main( String[] args ) {
    AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(Config.class);

    //run the importer
    final ImportNewOrders importer = (ImportNewOrders) ApplicationContextProvider.getApplicationContext().getBean("importNewOrders");
    importer.run();
    //importer.runInBackground();
}

这是我的配置:

@Configuration
@ComponentScan(basePackages = {
        "com.production"
})
@PropertySource(value = {
        "classpath:/application.properties",
        "classpath:/environment-${MY_ENVIRONMENT}.properties"
})
@EnableJpaRepositories("com.fettergroup.production.repositories")
@EnableTransactionManagement
public class Config {

    .... skipping things that aren't relevant

    @Bean
    public ImportNewOrders importNewOrders() {
        return new ImportNewOrders();
    }

这是我的班级......

@Component
public class ImportNewOrders implements Task {

    private final static Logger logger = Logger.getLogger(ImportNewOrders.class.getName());

    @Autowired
    private OrderService orderService;

    @Autowired
    private ImportOrderRequest importOrderRequest;

    @Value("${api.user}")
    private String apiUser;

    @Value("${api.password}")
    private String apiPassword;

    @Value("${api.orders.pingFrequency}")
    private String pingFrequency;

最后application.properties:

# ------------------- Application settings -------------------

#Base URL to the API application
api.baseUrl=http://localhost:9998

#Unique token used to authenticate this vendor
api.vendor.token=asdf

#API credentials
api.user=myuser
api.password=mypassword

#How often to check for new orders; frequency is in seconds
api.orders.pingFrequency=60

这工作一两个星期前,现在它决定它不喜欢这些价值观.我不知道为什么.一切看起来都对我不对.

更新

@Configuration
@ComponentScan(basePackages = {
        "com.production"
})
@PropertySource(value = {
        "classpath:/application.properties",
        "classpath:/environment-${MY_ENVIRONMENT}.properties"
})
@EnableJpaRepositories("com.production.repositories")
@EnableTransactionManagement
public class Config {
    @Value("${db.url}")
    private static String PROPERTY_DATABASE_URL;

    @Bean
    public DataSource dataSource() {
        MysqlDataSource dataSource = new MysqlDataSource();

        dataSource.setUrl(PROPERTY_DATABASE_URL); //is null
        /*dataSource.setUser(environment.getRequiredProperty(PROPERTY_NAME_DATABASE_USER));
        dataSource.setPassword(environment.getRequiredProperty(PROPERTY_NAME_DATABASE_PASSWORD));*/

        return dataSource;
    }

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

Answer 1

您的属性文件由您找到,@Configuration并且正在将其用于该类中的数据库属性,因为@PropertySource.但是,@Value领域和${}评估需要更多.

来自Javadoc@PropertySource

为了使用PropertySource中的属性解析定义中的$ {...}占位符或@Value注释,必须注册PropertySourcesPlaceholderConfigurer.在XML中使用时会自动发生这种情况,但在使用@Configuration类时必须使用静态@Bean方法显式注册.有关详细信息和示例,请参阅@Configuration Javadoc的"使用外部化值"部分和@Bean Javadoc的"关于BeanFactoryPostProcessor返回@Bean方法的说明"部分.

所以宣布一个

@Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
    PropertySourcesPlaceholderConfigurer p = new PropertySourcesPlaceholderConfigurer();
    p.setLocation(new ClassPathResource("your properties path"));
    // other properties
    return p;
}

在您的配置类中,或者如果您使用完全@PropertySource省略的话,在评论中恰当地提到了ach setLocation:

@Configuration
@PropertySource(value="classpath:your_file.properties")
public class MyConfiguration{

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

当你拥有环境时,你不应该需要环境 PropertySourcesPlaceholderConfigurer

但是,在大多数情况下,应用程序级bean不需要直接与Environment交互,而是可能必须将$ {...}属性值替换为属性占位符配置器,例如PropertySourcesPlaceholderConfigurer,它本身就是EnvironmentAware,并且当使用<context:property-placeholder />时,默认情况下会注册Spring 3.1.