SpringBoot运行时注入一个Bean

描述

使用GenericApplicationContext类的registerBean方法可以在项目运行时注入一个bean，获取GenericApplicationContext可以继承ApplicationContextAware，重写setApplicationContext，里面的参数就是ApplicationContext。

继承ApplicationContextAware

@RestController
@RequestMapping("/register/bean")
public class RegisterBeanController implements ApplicationContextAware {

    private ApplicationContext applicationContext;

    // AnnotationConfigServletWebServerApplicationContext
    @GetMapping("/example")
    public String registerBean() {
        GenericApplicationContext genericApplicationContext = (GenericApplicationContext) this.applicationContext;
        // ExampleBean没有使用任何的Component注解。
        genericApplicationContext.registerBean("ExampleBean", ExampleBean.class);
        ExampleBean exampleBean = (ExampleBean) applicationContext.getBean("ExampleBean");
        return exampleBean.getBeanData().getName();
    }


    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }
}

BeanData

@Component
public class BeanData {
    public String getName() {
        return "BeanData";
    }
}

ExampleBean

测试@Autowrite是否生效。

public class ExampleBean {
    private String name;
	
    @Autowired
    private BeanData beanData;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public BeanData getBeanData() {
        return beanData;
    }
}