SpringBoot之@ConfigurationProperties取消location注解后的替代方案

向右看齐 2024-04-19 11:49 30阅读 0赞

问题：

在`Spring Boot（版本1.5.1.RELEASE）`项目中，当准备映射自定义的配置文件属性到类中的时候，发现原本的`@ConfigurationProperties`注解已将`location`属性移除，因此导致无法正常给配置类的属性赋值

package org.springframework.boot.context.properties;
    
    import java.lang.annotation.Documented;
    import java.lang.annotation.ElementType;
    import java.lang.annotation.Retention;
    import java.lang.annotation.RetentionPolicy;
    import java.lang.annotation.Target;
    
    import org.springframework.core.annotation.AliasFor;
    
    /**
     * 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
     * @since 1.0.0
     * @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;
    
    }

解决方案：

1、使用安全类型加载

package cn.waggag.yatou.config.db;
    
    import lombok.Data;
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.context.annotation.PropertySource;
    import org.springframework.stereotype.Component;
    
    /**
     * @description: Druid的数据库参数配置，使用SpringBoot安全类型配置
     * @author: waggag
     * @time: 2019/9/17
     * @Company http://www.waggag.cn
     */
    @Data
    @Component
    @ConfigurationProperties(prefix = "jdbc")
    @PropertySource(value = "classpath:db.properties")
    public class DruidSettings {
        private String driver;
        private String url;
        private String username;
        private String password;
    }
    
    package cn.waggag.yatou.config.db;
    
    import com.alibaba.druid.pool.DruidDataSource;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.jdbc.core.JdbcTemplate;
    
    import javax.sql.DataSource;
    
    /**
     * @description: Druid数据库连接池的配置
     * @author: waggag
     * @time: 2019/9/17
     * @Company http://www.waggag.cn
     */
    @Configuration
    public class DruidConfig {
    
        @Autowired
        private DruidSettings druidSettings;
    
        @Bean
        public JdbcTemplate getJdbcTemplate() {
            return new JdbcTemplate(getDataSource());
        }
    
        public DataSource getDataSource() {
            DruidDataSource dataSource = new DruidDataSource();
            dataSource.setDriverClassName(druidSettings.getDriver());
            dataSource.setUrl(druidSettings.getUrl());
            dataSource.setUsername(druidSettings.getUsername());
            dataSource.setPassword(druidSettings.getPassword());
            return dataSource;
        }
    }

2、@ConfigurationProperties直接注解在方法上

package cn.waggag.yatou.config.db;
    
    import com.alibaba.druid.pool.DruidDataSource;
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    import javax.sql.DataSource;
    
    /**
     * @description: Druid的配置类
     * @author: waggag
     * @time: 2019/9/7
     * @Company http://www.waggag.cn
     */
    @Configuration
    public class DruidConfiguration {
        @ConfigurationProperties(prefix = "spring.database")
        @Bean
        public DataSource dataSource(){
            DruidDataSource druidDataSource = new DruidDataSource();
            return druidDataSource;
        }
    }