SpringBoot靜態(tài)獲取 bean的三種方式，你學(xué)會(huì)了嗎？

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來自：blog.csdn.net/showchi/article/details/97005720

• 方式一 ?注解@PostConstruct
• 方式二 ?啟動(dòng)類ApplicationContext
• 方式三 手動(dòng)注入ApplicationContext

方式一 ?注解@PostConstruct

import?com.example.javautilsproject.service.AutoMethodDemoService;
import?org.springframework.beans.factory.annotation.Autowired;
import?org.springframework.stereotype.Component;
?
import?javax.annotation.PostConstruct;
?
/**
?*?springboot靜態(tài)方法獲取?bean?的三種方式(一)
?*?@author:?clx
?*?@version:?1.1.0
?*/
@Component
public?class?StaticMethodGetBean_1?{
?
????@Autowired
????private?AutoMethodDemoService?autoMethodDemoService;
?
????@Autowired
????private?static?AutoMethodDemoService?staticAutoMethodDemoService;
?
????@PostConstruct
????public?void?init()?{
????????staticAutoMethodDemoService?=?autoMethodDemoService;
????}
?
????public?static?String?getAuthorizer()?{
????????return?staticAutoMethodDemoService.test();
????}
}

• 該方法不得有任何參數(shù)，除非是在 EJB 攔截器 (interceptor) 的情況下，根據(jù) EJB 規(guī)范的定義，在這種情況下它將帶有一個(gè) InvocationContext 對象 ；
• 該方法的返回類型必須為 void；
• 該方法不得拋出已檢查異常；
• 應(yīng)用 PostConstruct 的方法可以是 public、protected、package private 或 private；
• 除了應(yīng)用程序客戶端之外，該方法不能是 static；
• 該方法可以是 final；
• 如果該方法拋出未檢查異常，那么不得將類放入服務(wù)中，除非是能夠處理異常并可從中恢復(fù)的 EJB。

方式二 ?啟動(dòng)類ApplicationContext

?
import?org.springframework.boot.SpringApplication;
import?org.springframework.boot.autoconfigure.SpringBootApplication;
import?org.springframework.context.ConfigurableApplicationContext;
/**
?*?@author:?clx
?*?@version:?1.1.0
?*/
@SpringBootApplication
public?class?Application?{
????public?static?ConfigurableApplicationContext?ac;
????public?static?void?main(String[]?args)?{
???????ac?=?SpringApplication.run(Application.class,?args);
????}
?
}

/**
?*?@author:?clx
?*?@version:?1.1.0
?*/
@RestController
public?class?TestController?{
????/**
?????*?方式二
?????*/
????@GetMapping("test2")
????public?void?method_2()?{
????????AutoMethodDemoService?methodDemoService?=?Application.ac.getBean(AutoMethodDemoService.class);
????????String?test2?=?methodDemoService.test2();
????????System.out.println(test2);
????}
}

方式三 手動(dòng)注入ApplicationContext

import?org.springframework.beans.BeansException;
import?org.springframework.context.ApplicationContext;
import?org.springframework.context.ApplicationContextAware;
import?org.springframework.stereotype.Component;
?
?
/**
?*?springboot靜態(tài)方法獲取?bean?的三種方式(三)
?*?@author:?clx
?*?@version:?1.1.0
?*/
@Component
public?class?StaticMethodGetBean_3<T>?implements?ApplicationContextAware?{
????private?static?ApplicationContext?applicationContext;
????@Override
????public?void?setApplicationContext(ApplicationContext?applicationContext)?throws?BeansException?{
????????StaticMethodGetBean_3.applicationContext?=?applicationContext;
????}
?
????public?static??T??getBean(Class?clazz)?{
????????return?applicationContext?!=?null?applicationContext.getBean(clazz):null;
????}
}

????/**
?????*?方式三
?????*/
????@Test
????public?void?method_3()?{
????????AutoMethodDemoService?autoMethodDemoService?=?StaticMethodGetBean_3.getBean(AutoMethodDemoService.class);
????????String?test3?=?autoMethodDemoService.test3();
????????System.out.println(test3);
????}

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