Question

我们正在创建一个使用数据库作为存储库的新PropertySource。我们的想法是我们可以在运行时更新属性值。

与此同时，我们希望使用@ConfigurationProperties，以便我们可以包含验证以及使用application- {profile}命名约定。

但是，似乎@ConfigurationProperties的值仅从“applicationConfig：[path / to / config]”PropertySource加载。例如，以下测试：

private final String OVERRIDEN_VALUE = "overriden value";

@Before
public void before() {

    LOGGER.debug("Property sources are: "); 
    for(Iterator<?> it = env.getPropertySources().iterator(); it.hasNext(); ) {
        PropertySource<?> propertySource = (PropertySource<?>) it.next();
        LOGGER.debug(propertySource.getName());
    }

    EnvironmentTestUtils.addEnvironment("integrationTest", env, "some.prefix.overridable-property=" + OVERRIDEN_VALUE);

}

@Test
public void testOverridingDefaultProperties() {

    LOGGER.debug("MutablePropertySources value: {}", env.getProperty("some.prefix.overridable-property"));
    LOGGER.debug("@ConfigurationProperties value: {}", testProperties.getOverridableProperty());

    Assert.assertEquals(OVERRIDEN_VALUE, testProperties.getOverridableProperty());

}

生成此输出：

Property sources are: 
    systemProperties
    systemEnvironment
    random
    integrationTest
    applicationConfig: [classpath:/path/to/my/application.yml]

MutablePropertySources value: overriden value
@ConfigurationProperties value: default value

有关更多上下文，我最初在Spring Boot的Github here上提出了这个问题。

Answer 1

感谢Spring Boot的人们。向我指出Spring Cloud Context

http://projects.spring.io/spring-cloud/spring-cloud.html#customizing-bootstrap-property-sources

看起来这样可以解决问题。

<强>更新

由于我们已经编写了额外的数据库支持的numeric_limits，我们实际上只需要在运行时刷新PropertySource。与此同时，我们并不想刷新所有@ConfigurationProperties。为了完成刷新，我们做了以下事情：

创建了一个名为@ConfigurationProperties
创建了以下使用Spring Boot @ReloadableProperties

/**
 * 
 * Helper bean to reload {@code @ConfigurationProperties}
 * if the {@code @ConfigurationProperties} bean is annotated 
 * with {@code @ReloadableProperties}.
 * 
 * @author Jonathan Martin
 * @since 2.0.0
 * 
 * @see ReloadableProperties
 * @see ConfigurationPropertiesBindingPostProcessor
 *
 */
public class ConfigurationPropertiesReloader {

    private final ApplicationContext context;

    private final ConfigurationPropertiesBindingPostProcessor processor;

    @Autowired
    public ConfigurationPropertiesReloader(ApplicationContext context,  ConfigurationPropertiesBindingPostProcessor processor) {
        this.context = context;
        this.processor = processor;
    }

    /**
     * Reload all {@code @ConfigurationProperties}
     * annotated with {@code @ReloadableProperties}.
     */
    public void reload() {
        Map beans = context.getBeansWithAnnotation(ReloadableProperties.class);
        for (Map.Entry entry : beans.entrySet()) {

            String beanName = entry.getKey();
            Object bean = entry.getValue();

            ConfigurationProperties annotation = AnnotationUtils.findAnnotation(bean.getClass(), ConfigurationProperties.class);

            // Only reload the bean if it's an @ConfigurationProperties
            // Can't check for instance of ConfigurationPropertiesHolder 
            // because it uses package scope.
            if (annotation != null) {
                processor.postProcessBeforeInitialization(bean, beanName);
            }

        }
    }

}

现在，如果我将实用程序bean注入我的测试并调用reload，则测试通过。

如何构建自定义PropertySource以绑定到@ConfigurationProperties

1 个答案: