在开发过程中，我们可能需要动态获取spring容器中的某个bean的实例，此时我们就会用到ApplicationContext spring应用上下文，这里做一下记录，网上很多类似的的工具类。

先写好工具类再测试一下是否好用

工具类：

package com.zhh.demo.common.util;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * 容器应用上下文工具类
 * @author zhaoheng
 */
@Component
public class ApplicationContextUtil implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    /**
     * 将注入的 ApplicationContext 赋值给当前类中的applicationContext
     * @param applicationContext
     * @throws BeansException
     */
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        ApplicationContextUtil.applicationContext = applicationContext;
    }

    /**
     * 获取Spring的应用上下文
     * @return
     */
    public static ApplicationContext getContext(){
        return applicationContext;
    }

    /**
     * 根据bean名称获取到容器中的bean
     * */
    public static Object getBean(String name) {
        return applicationContext.getBean(name);
    }

    /**
     * 根据bean类型获取bean
     * */
    public static <T> T getBean(Class<T> clazz){
        return applicationContext.getBean(clazz);
    }

    /**
     * 根据bean类型和名称获取bean
     * */
    public static <T> T getBean(String name, Class<T> requiredType) {
        return applicationContext.getBean(name, requiredType);
    }

}

测试是否好用

创建一个bean并注入到容器

package com.zhh.demo.service;

import org.springframework.stereotype.Service;
/**
 * @Description: 测试bean
 * @Author: zhaoheng
 */
@Service
public class TestService {
    public void show(){
        System.out.println("TestService-show...");
    }
}

测试方法

package com.zhh.demo;

import com.zhh.demo.common.util.ApplicationContextUtil;
import com.zhh.demo.service.TestService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class ApplicationTest {
    @Autowired
    private ApplicationContextUtil applicationContextUtil;

    @Test
    void contextTest() {
        // 通过名称获取容器中的bean
        TestService userService1 = (TestService) applicationContextUtil.getBean("testService");
        userService1.show();
        System.out.println("---------------");
        // 通过class获取容器中的bean
        TestService testService2 = applicationContextUtil.getBean(TestService.class);
        testService2.show();
    }
}

测试结果：