BeanFactory

一个项目中会经常遇到的场景：在一些未被spring管理的JAVA类中，是不能通过@AutoWired和@Resource注入对象的。这种情况下，一种比较简单的方法实现接口ApplicationContextAware，ps : 目前项目中所使用的也是这种方式。

简单Demo

BeanFactory.java

package com.mpt.arguResolver;

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

/**
 * @author huangQiChang
 * @date 2019/7/2
 */
public class BeanFactory implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

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

    public static <T> T getBean(String beanName) {
        Object object = null;
        try {
            object = applicationContext.getBean(beanName);
        } catch (NoSuchBeanDefinitionException var3) {
            throw new RuntimeException(var3);
        }
        return (T) object;
    }

    public static <T> T getBean(Class<T> clazz) {
        T object = null;
        try {
            object = applicationContext.getBean(clazz);
        } catch (NoSuchBeanDefinitionException var3) {
        }
        return object;
    }
}

ArguresolverApplication.java（引导类）

package com.mpt.arguResolver;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
public class ArguresolverApplication {

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

    @Bean
    public BeanFactory beanFactory() {
        return new BeanFactory();
    }
}

MTest.java(未由spring管理的普通java类)

package com.mpt.arguResolver.test;

import com.mpt.arguResolver.BeanFactory;
import com.mpt.arguResolver.service.UserService;

/**
 * @author huangQiChang
 * @date 2019/7/2
 */
public class MTest {
    private static UserService userService;

    static {
        userService = BeanFactory.getBean(UserService.class);
    }
    public String testMethod() {
        String s = userService.service_test();
        return s;
    }
}

SpringBoot测试类：

package com.mpt.arguResolver;

import com.mpt.arguResolver.test.MTest;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class ArguresolverApplicationTests {

    @Test
    public void test() {
        MTest mTest = new MTest();
        mTest.testMethod();
    }
}
//可以正常获取UserServicce对象并执行其中的方法

注意实现ApplicationContextAware接口的BeanFactory这种类需要交由Spring容器管理,即被@Component注解或是SpringBoot的Application中通过@Bean的方式。