spring 加载properties文件（装配bean 四）

加载properties文件

注解配置方式

test.properties文件

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/heheda
jdbc.username=root
jdbc.password=root

配置文件扫描

@PropertySource(value = { "classpath:test.properties" }, ignoreResourceNotFound = true)
public class ApplicationConfig2 {

}

测试

		ApplicationContext context = new AnnotationConfigApplicationContext(ApplicationConfig2.class);
		String driver = context.getEnvironment().getProperty("jdbc.driver");
		System.out.println(driver);

测试成功

注解配置方式，占位符

配置注解ioc入口

@Configuration
@PropertySource(value = { "classpath:test.properties" }, ignoreResourceNotFound = true)
@ComponentScan(basePackages = { "priv.dengjl.spring.day2.bean" })
public class ApplicationConfig2 {

	@Bean
	public PropertySourcesPlaceholderConfigurer PropertySourcesPlaceholderConfigurer() {
		return new PropertySourcesPlaceholderConfigurer();
	}
}

占位符文件

@Component
public class DataSource {
	
	@Value("${jdbc.url}")
	private String url;
	@Value("${jdbc.password}")
	private String password;
	
	@Override
	public String toString() {
		return "DataSource [url=" + url + ", password=" + password + "]";
	}
}

测试

		ApplicationContext context = new AnnotationConfigApplicationContext(ApplicationConfig2.class);
		String driver = context.getEnvironment().getProperty("jdbc.driver");
		System.out.println(driver);
		DataSource bean = context.getBean(DataSource.class);
		System.out.println(bean);

测试通过

xml配置方式

xml配置

测试

		ApplicationContext context = new ClassPathXmlApplicationContext("Property.xml");
		DataSource dataSource = (DataSource) context.getBean("dataSource");
		System.out.println(dataSource);

测试通过