SpringBoot获取ApplicationContext的方法

ApplicationContext是Spring中的Bean工厂，可以用来获取Spring容器中的各种bean组件，注册监听事件，加载资源文件等功能

当一个类实现了这个接口（ApplicationContextAware）之后，这个类就可以方便获得ApplicationContext中的所有bean

创建实现ApplicationContextAware接口的静态类

package com.zhuhuix.startup.utils;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

/**
 * Spring工具类
 * @author zhuhuix
 * @date 2020-03-26
 */
public class SpringContextHolder implements ApplicationContextAware, DisposableBean {

    private static ApplicationContext applicationContext =null;

    /**
     * 获取applicationContext
     */
    public static ApplicationContext getApplicationContext() {
        if (applicationContext == null) {
            throw new IllegalStateException("applicaitonContext属性未注入, 请在SpringBoot启动类中注册SpringContextHolder.");
        }else {
            return applicationContext;
        }
    }

    /**
     * 通过name获取 Bean
     * @param name 类名称
     * @return 实例对象
     */
    public static Object getBean(String name){
        return getApplicationContext().getBean(name);
    }

    /**
     * 通过class获取Bean
     */
    public static <T> T getBean(Class<T> clazz){
        return getApplicationContext().getBean(clazz);
    }

    /**
     * 通过name,以及Clazz返回指定的Bean
     */
    public static <T> T getBean(String name,Class<T> clazz){
        return getApplicationContext().getBean(name, clazz);
    }


    @Override
    public void destroy() {
        applicationContext = null;
    }

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

启动类中通过@Bean注解注入静态类

package com.zhuhuix.startup;

import com.zhuhuix.startup.utils.SpringContextHolder;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@EnableAsync
@SpringBootApplication
@EnableTransactionManagement
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @Bean
    public SpringContextHolder springContextHolder(){
        return new SpringContextHolder();
    }

}

使用测试

package com.zhuhuix.startup.test1;

import lombok.Getter;
import lombok.Setter;
import org.springframework.stereotype.Component;

@Component
@Getter
@Setter
public class Person {

    private String name;

    private String age;

    private String sex;

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", age='" + age + '\'' +
                ", sex='" + sex + '\'' +
                '}';
    }
}

package com.zhuhuix.startup.test1;

import com.zhuhuix.startup.utils.SpringContextHolder;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
@Slf4j
public class PersonTest {

    @Test
    void test(){
        Person person = SpringContextHolder.getBean(Person.class);
        person.setName("张三");
        person.setAge("20");
        person.setSex("male");
        log.info(person.toString());
    }
}