Spring从属性文件读取@bean类的值

Question

我试图只使用注释创建Spring bean。我无法从属性文件加载@Bean类的值。

下面是我的代码：

public class AnnotationDI {

public static void main(String[] args) {
    ApplicationContext context = new AnnotationConfigApplicationContext(ConfigurationProvider.class);

    ApplicationProperties properties = (ApplicationProperties)context.getBean(ApplicationProperties.class);

    System.out.println(properties);

}}

@Configuration
public class ConfigurationProvider {

private ApplicationProperties m_applicationProperties;

@Bean
public ApplicationProperties getApplicationProperties() {
    return new ApplicationProperties();
}
}

@PropertySource(value = { "classpath:application.properties" })
public class ApplicationProperties {

@Value("${longThreadCount}")
private String m_longProcessThread;

@Value("${routeTimeout}")
private String m_routeTimeout;

@Value("${updateDirectoryPath}")
private String m_updateDirectoryPath;

public String getLongProcessThread() {
    return m_longProcessThread;
}
@Override
public String toString() {
    return "ApplicationProperties [m_longProcessThread=" +m_longProcessThread"]";
}
}

知道我做错了什么吗？

Answer 1

要能够解析具有占位符的@value,您需要注册一个PropertySourcesPlaceHolderConfigureer。由于这是一个BeanFactoryPostProcessor，因此需要将其注册为一个静态bean，以便能够在进程的早期检测到它。

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