SpringBoot自定义注解@YamlPropertySource加载yml或者yaml文件(扩展了@PropertySource)

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@YamlPropertySource。

2:实现

声明注解@YamlPropertySource

import org.springframework.context.annotation.PropertySource;
import org.springframework.core.io.support.PropertySourceFactory;
​
import java.lang.annotation.*;
​
/**
 * yaml property source and extension {@link PropertySource}
 *
 * @author liuenyuan
 * @see org.springframework.context.annotation.PropertySource
 **/
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Repeatable(YamlPropertySources.class)
public @interface YamlPropertySource {
​
​
    /**
     * 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.
     * 
Both traditional and XML-based properties file formats are supported
     * — for example, {@code "classpath:/com/myco/app.properties"}
     * or {@code "file:/path/to/file.xml"}.
     * 
Resource location wildcards (e.g. **/*.properties) are not permitted;
     * each location must evaluate to exactly one {@code .properties} resource.
     * 
${...} placeholders will be resolved against any/all property sources already
     * registered with the {@code Environment}. See {@linkplain PropertySource above}
     * for examples.
     * 
Each location will be added to the enclosing {@code Environment} as its own
     * property source, and in the order declared.
     */
    String[] value();
​
    /**
     * Indicate if failure to find the a {@link #value() property resource} should be
     * ignored.
     * 
{@code true} is appropriate if the properties file is completely optional.
     * 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.
     * 
By default, a default factory for standard resource files will be used.
     *
     * @see org.springframework.core.io.support.DefaultPropertySourceFactory
     * @see org.springframework.core.io.support.ResourcePropertySource
     * @since 4.3
     */
    Classextends PropertySourceFactory> factory() default YamlPropertySourceFactory.class;
}
​
​
/**
 * @author liuenyuan
 * @see YamlPropertySource
 **/
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface YamlPropertySources {
​
    YamlPropertySource[] 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 YamlPropertySource} bean post processor.this class convert the yml or yaml file {@link YamlPropertySource#value()} to {@link PropertiesPropertySource},and add the property source
 * named {@link YamlPropertySource#name()} into {@link Environment}.When you use this annotation,you
 * must for follow example:
 * 
{@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;
 * }}
 *
 * @author liuenyuan
 * @date 2019/6/16 20:13
 * @describe
 * @see YamlPropertySource
 * @see InstantiationAwareBeanPostProcessorAdapter
 * @see EnvironmentAware
 * @see ResourceLoaderAware
 */
@Slf4j
@Configuration(value = YamlPropertySourceAnnotationPostProcessor.BEAN_NAME)
@Order(Ordered.HIGHEST_PRECEDENCE)
public class YamlPropertySourceAnnotationPostProcessor extends InstantiationAwareBeanPostProcessorAdapter implements EnvironmentAware, ResourceLoaderAware {
​
    public final static String BEAN_NAME = "yamlPropertySourceAnnotationPostProcessor";
​
    private Environment environment;
​
    private ResourceLoader resourceLoader;
​
    private final List<String> propertySourceNames = new ArrayList<>();
​
    private static final PropertySourceFactory DEFAULT_PROPERTY_SOURCE_FACTORY = new YamlPropertySourceFactory();
​
    @Override
    public void setEnvironment(Environment environment) {
        Assert.isInstanceOf(ConfigurableEnvironment.class, environment, "environment must be instance of ConfigurableEnvironment.");
        this.

转载于:https://www.cnblogs.com/liuenyuan1996/p/11033080.html