SpringBoot获取Bean的工具类

1、beanName

• 默认是类名首字母小写
  
  下面的类：beanName = bean1

@Component
public class Bean1 {

    public String getBean1() {
        return "Bean1";
    }
}

• 修改beanName
  
  下面的类：beanName = bean2New

@Component("bean2New")
public class Bean2 {

    public String getBean2() {
        return "Bean2";
    }
}

2、工具类

package com.cc.eed.utils;

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

/**
 * <p>获取spring的bean的工具类</p>
 *
 * @author CC
 * @since 2023/10/12
 */
@Component
public class SpringBeanUtil implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

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

    /** <p>根据类的clazz获取<p>
     * @param clazz clazz
     * @return {@link T}
     * @since 2023/10/12
     * @author CC
     **/
    public static <T> T getBean(Class<T> clazz) {
        T t = applicationContext != null ? applicationContext.getBean(clazz) : null;
        Assert.notNull(t, "当前Bean为空，请重新选择！");
        return t;
    }

    /** <p>根据Bean名字获取<p>
     * @param clazzName bean名字
     * @return {@link Object}
     * @since 2023/10/12
     * @author CC
     **/
    public static Object getBean(String clazzName) {
        return applicationContext.getBean(clazzName);
    }
}

3、使用

    @Test
    public void test01()throws Exception{
        //方式一：根据类的clazz获取
        Bean1 bean = SpringBeanUtil.getBean(Bean1.class);
        System.out.println(bean.getBean1());
        Bean2 bean2 = SpringBeanUtil.getBean(Bean2.class);
        System.out.println(bean2.getBean2());

        //方式二：根据bean名字获取
        Bean1 bean11 = (Bean1) SpringBeanUtil.getBean("bean1");
        System.out.println(bean11.getBean1());
        //报错：NoSuchBeanDefinitionException
        Bean2 bean22 = (Bean2) SpringBeanUtil.getBean("bean2");
        //正确
        Bean2 bean222 = (Bean2) SpringBeanUtil.getBean("bean2New");
        System.out.println(bean222.getBean2());
    }