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Spring：ApplicationContextAware获取Spring上下文

1 前言

实现ApplicationContextAware接口，即可通过实现setApplicationContext方法，获取Spring的上下文，同时使用@Component注解即可生效。

2 使用

根据Spring上下文，获取bean的工具类封装：

package com.xiaoxu.crawler.utils;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.lang.NonNull;

import org.springframework.stereotype.Component;


/**
 * @author xiaoxu
 * @date 2022-12-31 9:08
 * crawlerJ:com.xiaoxu.crawler.utils.ApplicationContextUtil
 */
@Component
public class ApplicationContextUtil implements ApplicationContextAware {

    private ApplicationContext applicationContext;

    public ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    @Override
    public void setApplicationContext(@NonNull ApplicationContext applicationContext) throws BeansException {
        System.out.println("我是applicationContextAware:");
        this.applicationContext = applicationContext;
    }

    public <T> T getBean(Class<T> clazz){
        T bean = null;
        try {
            bean = getApplicationContext().getBean(clazz);
        } catch (BeansException e) {
            ExcpUtils.throwExp("get bean by class fail: "+e.getMessage());
        }
        return bean;
    }

    public Object getBean(String name){
        Object bean = null;
        try {
            bean = getApplicationContext().getBean(name);
        } catch (BeansException e) {
            ExcpUtils.throwExp("get bean by name fail: "+e.getMessage());
        }
        return bean;
    }

    public <T> T getBean(String name, Class<T> clazz){
        T bean = null;
        try {
            bean = getApplicationContext().getBean(name, clazz);
        } catch (BeansException e) {
            ExcpUtils.throwExp("get bean by name and class fail: "+e.getMessage());
        }
        return bean;
    }
}