技术交流：springboot优雅获取自定义yml文件内容值

@PropertySource

功能：@PropertySource注解用于指定资源文件读取的位置，它不仅能读取properties文件，也能读取xml文件，并且通过YAML解析器，配合自定义PropertySourceFactory实现解析YAML文件。

源码：

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Repeatable(PropertySources.class)
public @interface PropertySource {

	/**
	 * Indicate the name of this property source. If omitted, the {@link #factory}
	 * will generate a name based on the underlying resource (in the case of
	 * {@link org.springframework.core.io.support.DefaultPropertySourceFactory}:
	 * derived from the resource description through a corresponding name-less
	 * {@link org.springframework.core.io.support.ResourcePropertySource} constructor).
	 * @see org.springframework.core.env.PropertySource#getName()
	 * @see org.springframework.core.io.Resource#getDescription()
	 */
	String name() default "";

	/**
	 * Indicate the resource location(s) of the properties file to be loaded.
	 * <p>Both traditional and XML-based properties file formats are supported
	 * &mdash; for example, {@code "classpath:/com/myco/app.properties"}
	 * or {@code "file:/path/to/file.xml"}.
	 * <p>Resource location wildcards (e.g. *&#42;/*.properties) are not permitted;
	 * each location must evaluate to exactly one {@code .properties} or {@code .xml}
	 * resource.
	 * <p>${...} placeholders will be resolved against any/all property sources already
	 * registered with the {@code Environment}. See {@linkplain PropertySource above}
	 * for examples.
	 * <p>Each location will be added to the enclosing {@code Environment} as its own
	 * property source, and in the order declared.
	 */
	String[] value();

	/**
	 * Indicate if a failure to find a {@link #value property resource} should be
	 * ignored.
	 * <p>{@code true} is appropriate if the properties file is completely optional.
	 * <p>Default is {@code false}.
	 * @since 4.0
	 */
	boolean ignoreResourceNotFound() default false;

	/**
	 * A specific character encoding for the given resources, e.g. "UTF-8".
	 * @since 4.3
	 */
	String encoding() default "";

	/**
	 * Specify a custom {@link PropertySourceFactory}, if any.
	 * <p>By default, a default factory for standard resource files will be used.
	 * @since 4.3
	 * @see org.springframework.core.io.support.DefaultPropertySourceFactory
	 * @see org.springframework.core.io.support.ResourcePropertySource
	 */
	Class<? extends PropertySourceFactory> factory() default PropertySourceFactory.class;

}

@Value

功能：该注解的作用是将我们配置文件的属性读出来，有@Value(“${}”)和@Value(“#{}”)两种方式。

源码：

@Target({ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER, ElementType.ANNOTATION_TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Value {

	/**
	 * The actual value expression such as <code>#{systemProperties.myProp}</code>
	 * or property placeholder such as <code>${my.app.myProp}</code>.
	 */
	String value();

}

示例代码

思路： 将自定义的aliyun.yml配置文件信息获取到spring中，便于源站url替换成cdn站点，防止资源盗链。

1. 配置aliyun.yml

aliyun:
	cdn:
		url: https://cdn.aliyun.com
		privateKey: aliyuncdnkey

2. 创建ALiYunCdnConfig类

@Component
@Getter
@Setter
@PropertySource("classpath:aliyun.yml")
public class ALiYunCdnConfig {

    @Value("${aliyun.cdn.url}")
    private String url;

    @Value("${aliyun.cdn.privateKey}")
    private String privateKey;
    
}

3. 测试获取

编写相应的controller，依赖注入该ALiYunCdnConfig，对需要的源站url进行操作后返回加密后的cdn。