SpringBoot源码分析[email protected]如何生效

查看@ConfigurationPropertis源码

/**
 * Annotation for externalized configuration. Add this to a class definition or a
 * {@code @Bean} method in a {@code @Configuration} class if you want to bind and validate
 * some external Properties (e.g. from a .properties file).
 * <p>
 * Note that contrary to {@code @Value}, SpEL expressions are not evaluated since property
 * values are externalized.
 *
 * @author Dave Syer
 * @see ConfigurationPropertiesBindingPostProcessor
 * @see EnableConfigurationProperties
 */
@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ConfigurationProperties {

	/**
	 * The name prefix of the properties that are valid to bind to this object. Synonym
	 * for {@link #prefix()}. A valid prefix is defined by one or more words separated
	 * with dots (e.g. {@code "acme.system.feature"}).
	 * @return the name prefix of the properties to bind
	 */
	@AliasFor("prefix")
	String value() default "";

	/**
	 * The name prefix of the properties that are valid to bind to this object. Synonym
	 * for {@link #value()}. A valid prefix is defined by one or more words separated with
	 * dots (e.g. {@code "acme.system.feature"}).
	 * @return the name prefix of the properties to bind
	 */
	@AliasFor("value")
	String prefix() default "";

	/**
	 * Flag to indicate that when binding to this object invalid fields should be ignored.
	 * Invalid means invalid according to the binder that is used, and usually this means
	 * fields of the wrong type (or that cannot be coerced into the correct type).
	 * @return the flag value (default false)
	 */
	boolean ignoreInvalidFields() default false;

	/**
	 * Flag to indicate that when binding to this object unknown fields should be ignored.
	 * An unknown field could be a sign of a mistake in the Properties.
	 * @return the flag value (default true)
	 */
	boolean ignoreUnknownFields() default true;

}

只有prefix属性，看see到相关处理类

 * @see ConfigurationPropertiesBindingPostProcessor
 * @see EnableConfigurationProperties

ConfigurationPropertiesBindingPostProcessor源码

属性设置

@Override
	public void afterPropertiesSet() throws Exception {
		// We can't use constructor injection of the application context because
		// it causes eager factory bean initialization
		this.beanFactoryMetadata = this.applicationContext.getBean(
				ConfigurationBeanFactoryMetadata.BEAN_NAME,
				ConfigurationBeanFactoryMetadata.class);
		this.configurationPropertiesBinder = new ConfigurationPropertiesBinder(
				this.applicationContext, VALIDATOR_BEAN_NAME);
	}

postProcessBeforeInitialization方法