Spring中@PropertySource注解

作用：用于指定properties文件的位置。
属性：

• value：指定文件的名称和路径。关键字：classpath，表示类路径下。

示例（在Spring中@Import注解基础上）：
jdbcConfig.properties

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/springtest?serverTimezone=UTC
jdbc.username=root
jdbc.password=1234

JdbcConfig类：

package config;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.apache.commons.dbutils.QueryRunner;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;

import javax.sql.DataSource;

//和spring连接数据库相关的配置类
@Configuration

public class JdbcConfig {

    @Value("${jdbc.driver}")
    private String driver;

    @Value("${jdbc.url}")
    private String url;

    @Value("${jdbc.username}")
    private String username;

    @Value("${jdbc.password}")
    private String password;

    //用于创建一个QueryRunner对象
    @Bean(name = "runner")
    @Scope(value = "prototype")
    public QueryRunner createQueryRunner(DataSource dataSource) {
        return new QueryRunner(dataSource);
    }

    //创建数据源对象
    @Bean(name = "dataSource")
    public DataSource createDataSource() {
        try {
            ComboPooledDataSource ds = new ComboPooledDataSource();
            ds.setDriverClass(driver);
            ds.setJdbcUrl(url);
            ds.setUser(username);
            ds.setPassword(password);
            return ds;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

SpringConfiguration类：

package config;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.apache.commons.dbutils.QueryRunner;
import org.springframework.context.annotation.*;

import javax.sql.DataSource;

//该类是一个配置类，它的作用和bean.xml是一样的
@Configuration
@ComponentScan(basePackages = {"com.qublog","config"})
@Import(value = {JdbcConfig.class})
@PropertySources({
        @PropertySource("classpath:jdbcConfig.properties")
})
public class SpringConfiguration {

}

AccountServiceTest类：

    @Test
    public void testFindAll() {
        //获取容器
//        ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");
        ApplicationContext ac = new AnnotationConfigApplicationContext(SpringConfiguration.class);
        //得到业务层对象
        AccountService as = (AccountService) ac.getBean("accountService");
        //执行方法
        List<Account> accounts = as.findAllAccount();
        for (Account account:accounts) {
            System.out.println(account);
        }
    }