SpringBoot @Import

淡淡的烟草味﹌ 2021-12-12 10:13 203阅读 0赞

SpringBoot 的 @Import 用于将指定的类实例注入之Spring IOC Container中。

A.java(无任何属性和实现)

public class A {
    }

B.java(无任何属性和实现)

public class B {
    }

ImportDirect.java

import com.example.demo.model.A;
    import com.example.demo.model.B;
    import org.springframework.context.annotation.Import;
    import org.springframework.stereotype.Component;
    
    @Component
    @Import({A.class, B.class})
    public class ImportDirect {
    }

代码解读：使用@Import(\{A.class, B.class\})后 A和 B类的实例将会被注入之Spring IOC Container中

DemoApplication.java 启动类

import com.example.demo.model.A;
    import com.example.demo.model.B;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.context.ConfigurableApplicationContext;
    
    @SpringBootApplication
    public class DemoApplication {
    
        public static void main(String[] args) {
            ConfigurableApplicationContext applicationContext = SpringApplication.run(DemoApplication.class, args);
    
            System.out.println(applicationContext.getBean(ImportDirect.class));
            System.out.println(applicationContext.getBean(A.class));
            System.out.println(applicationContext.getBean(B.class));
        }
    
    }

启动SpringBoot查看控制台执行情况

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzM3NzMyODI5_size_16_color_FFFFFF_t_70][]

或者另一种方法，使用注解

自定义注解@EnableAB

import com.example.demo.model.A;
    import com.example.demo.model.B;
    import org.springframework.context.annotation.Import;
    
    import java.lang.annotation.ElementType;
    import java.lang.annotation.Retention;
    import java.lang.annotation.RetentionPolicy;
    import java.lang.annotation.Target;
    
    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.RUNTIME)
    @Import({A.class, B.class})
    public @interface EnableAB {
    }

DemoApplication.java 启动类

import com.example.demo.model.A;
    import com.example.demo.model.B;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.context.ConfigurableApplicationContext;
    
    @EnableAB
    @SpringBootApplication
    public class DemoApplication {
    
        public static void main(String[] args) {
            ConfigurableApplicationContext applicationContext = SpringApplication.run(DemoApplication.class, args);
    
            System.out.println(applicationContext.getBean(A.class));
            System.out.println(applicationContext.getBean(B.class));
        }
    
    }

启动SpringBoot查看控制台执行情况

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzM3NzMyODI5_size_16_color_FFFFFF_t_70 1][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzM3NzMyODI5_size_16_color_FFFFFF_t_70]: /images/20211211/19a10fafde984e54bdeeeb025041ee78.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzM3NzMyODI5_size_16_color_FFFFFF_t_70 1]: /images/20211211/c59ad2654aad4a588a3c13653595777f.png