1:概述

SpringBoot的@PropertySource注解只支持加载 properties结尾的文件。当使用@ConfigurationProperties

注解配合@EnableConfigurationProperties注解将配置转换为JavaBean时,可能需要配合@PropertySource

注解加载指定的配置文件。所以为了支持以yml或者yaml文件,我自定义了注解@YmlPropertySource。

2:实现

声明注解@YmlPropertySource

/**
 * 类描述: load yml or yaml file into {@link org.springframework.core.env.Environment}
 *
 * @author liuenyuan
 * @date 2019/6/16 20:12
 * @describe
 */
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface YmlPropertySource {
​
    /**
     * Indicate the name of this property source. If omitted, a name will
     * be generated based on the description of the underlying resource.
     *
     * @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.yml|yaml"}
     * <p>Resource location wildcards (e.g. **/*.yml|yaml) are not permitted;
     * each location must evaluate to exactly one {@code .properties} resource.
     * <p>${...} placeholders will be resolved against any/all property sources already
     * registered with the {@code Environment}. See {@linkplain YmlPropertySource 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();
}
​

具体实现如下

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessorAdapter;
import org.springframework.beans.factory.config.YamlPropertiesFactoryBean;
import org.springframework.context.EnvironmentAware;
import org.springframework.context.ResourceLoaderAware;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.core.annotation.Order;
import org.springframework.core.env.*;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.util.Assert;
​
import java.io.IOException;
import java.util.*;
​
/**
 * 类描述: {@link YmlPropertySource} bean post processor.this class convert the yml or yaml file
 * {@link YmlPropertySource#value()} to {@link PropertiesPropertySource},and add the property source
 * named {@link YmlPropertySource#name()} into {@link Environment}.When you use this annotation,you
 * must for follow example:
 * <pre>{@code
 * @link @ConfigurationProperties(prefix = "person")
 * @link @YmlPropertySource(value = {"classpath:/hello.yml"}, name = "hello")
 * @link @Data
 * public class PersonProperties {
 *
 * private String name;
 *
 * private Integer age;
 *
 * private String school;
 * }}</pre>
 *
 * @author liuenyuan
 * @date 2019/6/16 20:13
 * @describe
 * @see YmlPropertySource
 * @see InstantiationAwareBeanPostProcessorAdapter
 * @see EnvironmentAware
 * @see ResourceLoaderAware
 */
@Slf4j
@Configuration
@Order(Ordered.HIGHEST_PRECEDENCE)
public class YmlPropertySourceAnnotationBeanPostProcessor extends InstantiationAwareBeanPostProcessorAdapter implements EnvironmentAware, ResourceLoaderAware {
​
    private Environment environment;
​
    private ResourceLoader resourceLoader;
​
    @Override
    public void setEnvironment(Environment environment) {
        Assert.isInstanceOf(ConfigurableEnvironment.class, environment, "environment must be instance of ConfigurableEnvironment.");
        this.environment = environment;
    }
​
    @Override
    public void setResourceLoader(ResourceLoader resourceLoader) {
        this.resourceLoader = resourceLoader;
    }
​
​
    @Override
    public boolean postProcessAfterInstantiation(Object bean, String beanName) throws BeansException {