自定义Yaml解析器替换Properties文件

项目结构

案例代码

配置类SpringConfiguration

@Configuration

@Import(JdbcCofnig.class)

@PropertySource(value = "classpath:/jdbc.yml",factory = YamlPropertySourceFactory.class)

public class SpringConfiguration {

}

---

JdbcConfig

package config;

import org.springframework.beans.factory.annotation.Value;

import org.springframework.context.annotation.Bean;

import org.springframework.jdbc.datasource.DriverManagerDataSource;

import javax.sql.DataSource;

/**

 * JDBC配置类

 * @Author Helius

 * @Create 2019-11-01-19:47

 */

public class JdbcCofnig {

    @Value("${jdbc.driver}")

    private String driver;

    @Value("${jdbc.url}")

    private String url;

    @Value("${jdbc.username}")

    private String username;

    @Value("${jdbc.password}")

    private String password;

    @Bean("datasource")

    public DataSource createDataSource() {

        System.out.println("驱动类是：" + driver);

        //1.创建Spring内置数据源

        DriverManagerDataSource dataSource = new DriverManagerDataSource();

        //2.给数据源填充属性

        dataSource.setDriverClassName(driver);

        dataSource.setUrl(url);

        dataSource.setUsername(username);

        dataSource.setPassword(password);

        return dataSource;

    }

}

# Yet Another Markup Language 另一种标记语言

# YAML yml

#键和值之间用冒号和空格分隔

jdbc:

    driver: com.mysql.jdbc.Driver

    url: jdbc:mysql://localhost:3306/spring_ioc

    username: root

    password: admin

---

解释：

对于properties文件的解析，

spring4.3以后，我们无须在配置

<!-- 数据库配置文件位置 --> <context:property-placeholder location="classpath:jdbc.properties" />

或者

<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">

    <property name="locations">

        <value>jdbc.properties</value>

    </property>

    <property name="fileEncoding">

       <value>UTF-8</value>

    </property>

</bean>

默认使用的是

默认使用PropertySourceFactory接口的唯一实现类DefaultPropertySourceFactory来解析properties文件，参见@PropertySource注解

该类也支持xml，但并不支持yml格式。

yml格式是springboot所推荐的配置文件格式。

---

那如果使用yml格式就需要我们自定义解析器.

1. 首先需要入第三方yml解析器

        <!--导入yaml文件解析器坐标-->

        <dependency>

            <groupId>org.yaml</groupId>

            <artifactId>snakeyaml</artifactId>

            <version>1.23</version>

        </dependency>

1. 然后自定义类型解析器

@PropertySource(value = "classpath:/jdbc.yml",factory = YamlPropertySourceFactory.class)

通过配置类的@PropertySource注解的factory属性

1. 解析类YamlPropertySourceFactory

/**

 * 自定义解析yaml文件的工厂类

 *引入yaml文件解析器

 * @Author Helius

 * @Create 2019-11-01-21:51

 */

public class YamlPropertySourceFactory implements PropertySourceFactory {

    @Override

    public PropertySource<?> createPropertySource(String name, EncodedResource resource) throws IOException {

        //1.创建yaml文件解析工厂

        YamlPropertiesFactoryBean factoryBean = new YamlPropertiesFactoryBean();

        //2.设置要解析的资源内容

        factoryBean.setResources(resource.getResource());

        //3.把资源解析成解析成properties文件

        Properties properties = factoryBean.getObject();

        //返回PropertySource对象

        return (name != null ? new PropertiesPropertySource(name, properties) : new PropertiesPropertySource(resource.getResource().getFilename(), properties));

    }

}

1. 测试类

/**

 * 测试类

 * @Author Helius

 * @Create 2019-11-01-19:54

 */

public class SpringPropertySourceTest  {

    public static void main(String[] args) throws SQLException {

        ApplicationContext ac = new AnnotationConfigApplicationContext(SpringConfiguration.class);

        DataSource datasource = ac.getBean("datasource", DataSource.class);

        Connection connection = datasource.getConnection();

        connection.close();

    }

}

控制台输出：

驱动类是：com.mysql.jdbc.Driver