#############################Configuration使用示例######################################################
/**
 * 1、配置類里面使用@Bean標注在方法上給容器注冊組件，默認也是單實例的
 * 2、配置類本身也是組件
 * 3、proxyBeanMethods：代理bean的方法
 *      Full(proxyBeanMethods = true)、【保證每個@Bean方法被調用多少次返回的組件都是單實例的】
 *      Lite(proxyBeanMethods = false)【每個@Bean方法被調用多少次返回的組件都是新創(chuàng)建的】
 *      組件依賴必須使用Full模式默認。其他默認是否Lite模式
 *
 *
 *
 */
@Configuration(proxyBeanMethods = false) //告訴SpringBoot這是一個配置類 == 配置文件
public class MyConfig {
    /**
     * Full:外部無論對配置類中的這個組件注冊方法調用多少次獲取的都是之前注冊容器中的單實例對象
     * @return
     */
    @Bean //給容器中添加組件。以方法名作為組件的id。返回類型就是組件類型。返回的值，就是組件在容器中的實例
    public User user01(){
        User zhangsan = new User("zhangsan", 18);
        //user組件依賴了Pet組件
        zhangsan.setPet(tomcatPet());
        return zhangsan;
    }
    @Bean("tom")
    public Pet tomcatPet(){
        return new Pet("tomcat");
    }
}
################################@Configuration測試代碼如下########################################
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan("com.atguigu.boot")
public class MainApplication {
    public static void main(String[] args) {
        //1、返回我們IOC容器
        ConfigurableApplicationContext run = SpringApplication.run(MainApplication.class, args);
 
        //2、查看容器里面的組件
        String[] names = run.getBeanDefinitionNames();
        for (String name : names) {
            System.out.println(name);
        }
        //3、從容器中獲取組件
        Pet tom01 = run.getBean("tom", Pet.class);
        Pet tom02 = run.getBean("tom", Pet.class);
        System.out.println("組件："+(tom01 == tom02));

        //4、com.atguigu.boot.config.MyConfig$$EnhancerBySpringCGLIB$$51f1e1ca@1654a892
        MyConfig bean = run.getBean(MyConfig.class);
        System.out.println(bean);
 
        //如果@Configuration(proxyBeanMethods = true)代理對象調用方法。SpringBoot總會檢查這個組件是否在容器中有。
        //保持組件單實例
        User user = bean.user01();
        User user1 = bean.user01();
        System.out.println(user == user1);
        User user01 = run.getBean("user01", User.class);
        Pet tom = run.getBean("tom", Pet.class);
        System.out.println("用戶的寵物："+(user01.getPet() == tom));

    }
}

 * 4、@Import({User.class, DBHelper.class})
 *      給容器中自動創(chuàng)建出這兩個類型的組件、默認組件的名字就是全類名
 *
 *
 *
 */
@Import({User.class, DBHelper.class})
@Configuration(proxyBeanMethods = false) //告訴SpringBoot這是一個配置類 == 配置文件
public class MyConfig {
}

=====================測試條件裝配==========================
@Configuration(proxyBeanMethods = false) //告訴SpringBoot這是一個配置類 == 配置文件
//@ConditionalOnBean(name = "tom")
@ConditionalOnMissingBean(name = "tom")
public class MyConfig {
    /**
     * Full:外部無論對配置類中的這個組件注冊方法調用多少次獲取的都是之前注冊容器中的單實例對象
     * @return
     */
    @Bean //給容器中添加組件。以方法名作為組件的id。返回類型就是組件類型。返回的值，就是組件在容器中的實例
    public User user01(){
        User zhangsan = new User("zhangsan", 18);
        //user組件依賴了Pet組件
        zhangsan.setPet(tomcatPet());
        return zhangsan;
    }
 
    @Bean("tom22")
    public Pet tomcatPet(){
        return new Pet("tomcat");
    }
}
public static void main(String[] args) {
        //1、返回我們IOC容器
        ConfigurableApplicationContext run = SpringApplication.run(MainApplication.class, args);
 
        //2、查看容器里面的組件
        String[] names = run.getBeanDefinitionNames();
        for (String name : names) {
            System.out.println(name);
        }
        boolean tom = run.containsBean("tom");
        System.out.println("容器中Tom組件："+tom);
        boolean user01 = run.containsBean("user01");
        System.out.println("容器中user01組件："+user01);
        boolean tom22 = run.containsBean("tom22");
        System.out.println("容器中tom22組件："+tom22);
    }

======================beans.xml=========================
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
 
    <bean id="haha" class="com.atguigu.boot.bean.User">
        <property name="name" value="zhangsan"></property>
        <property name="age" value="18"></property>
    </bean>
 
    <bean id="hehe" class="com.atguigu.boot.bean.Pet">
        <property name="name" value="tomcat"></property>
    </bean>
</beans>

@ImportResource("classpath:beans.xml")
public class MyConfig {}
 
======================測試=================
        boolean haha = run.containsBean("haha");
        boolean hehe = run.containsBean("hehe");
        System.out.println("haha："+haha);//true
        System.out.println("hehe："+hehe);//true

public class getProperties {
     public static void main(String[] args) throws FileNotFoundException, IOException {
         Properties pps = new Properties();
         pps.load(new FileInputStream("a.properties"));
         Enumeration enum1 = pps.propertyNames();//得到配置文件的名字
         while(enum1.hasMoreElements()) {
             String strKey = (String) enum1.nextElement();
             String strValue = pps.getProperty(strKey);
             System.out.println(strKey + "=" + strValue);
             //封裝到JavaBean。
         }
     }
 }

/**
 * 只有在容器中的組件，才會擁有SpringBoot提供的強大功能
 */
@Component
@ConfigurationProperties(prefix = "mycar")
public class Car {
    private String brand;
    private Integer price;
 
    public String getBrand() {
        return brand;
    }
    public void setBrand(String brand) {
        this.brand = brand;
    }
    public Integer getPrice() {
        return price;
    }
    public void setPrice(Integer price) {
        this.price = price;
    }
    @Override
    public String toString() {
        return "Car{" +
                "brand='" + brand + '\'' +
                ", price=" + price +
                '}';
    }
}

@Import(AutoConfigurationPackages.Registrar.class) ?//給容器中導入一個組件
public @interface AutoConfigurationPackage {}

//利用Registrar給容器中導入一系列組件
//將指定的一個包下的所有組件導入進來，MainApplication 所在包下。