随着越来越多地使用Springboot敏捷开发，更多地使用注解配置Spring,而不是Spring的applicationContext.xml文件。

• Configuration注解： Spring解析为配置类，相当于spring配置文件

• Bean注解：容器注册Bean组件，默认id为方法名

  @Configuration public class AppConfig { @Bean public MyService myService() { return new MyServiceImpl(); } }

等同于beans.xml文件

<beans>
    <bean id="myService" class="com.acme.services.MyServiceImpl"/>
</beans>

1）applicationContext.xml文件-包扫描

@ComponentScans(value = {@ComponentScan(value = "com.self",excludeFilters = {
                @Filter(type = FilterType.ANNOTATION,classes = {Controller.class})
        })
})
@Configuration
public class RootConfig {
    
      //测试Bean
      @Bean
      public Person person() {
          return new Person("张励",22,"工程师");
      }
}

2）导入properties文件

@PropertySource(value = {"classpath:person.properties"})
@Configuration
public class MainConfigOfProperty {

    @Bean
    public Person person() {
        return new Person();
    }
}

赋值

public class Person {

   @Value("${person.name}")//配置文件属性
    private String name;

}

3）数据源

@EnableTransactionManagement//开启基于注解的事务管理功能
@ComponentScan("com.self.ds")
@Configuration
public class TxConfig {
    
    //数据源
    @Bean
    public DataSource dataSource() throws Exception{
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser("root");
        dataSource.setPassword("000111");
        dataSource.setDriverClass("com.mysql.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/self");
        return dataSource;
    }
    
     
    @Bean
    public JdbcTemplate jdbcTemplate() throws Exception{ 
        JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource());
        return jdbcTemplate;
    }
    
    //事务管理器
    @Bean
    public PlatformTransactionManager transactionManager() throws Exception{
        return new DataSourceTransactionManager(dataSource());
    }
    

}

单元测试

public class IOCTest {
    
    AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfig.class);  
    
    @Test
    public void test02() {
        Object bean1 = applicationContext.getBean("person");
        Object bean2 = applicationContext.getBean("person");
        System.out.println( bean1 == bean2);
    }
    
    @Test
    public void test01() {
        Object bean = applicationContext.getBean("person01");
        System.out.println("结果: " + bean);
    }
    
    
    @Test
    public void test() { 
        String[] beanDefinitionNames = applicationContext.getBeanDefinitionNames();
        for(String beanDef:beanDefinitionNames) {
            System.out.println("输出: " + beanDef);
        }
        
    }

}

执行结果