多线程无法注入kafkaTemplate（或者其他类）问题

1、问题：

在线程runnable中，无法将需要的kafkaTemplate（或者其他类）注入

 

2、解决方案：

通过封装ApplicationContex类（继承ApplicationContextAware），获取kafkaTemplate的bean实例。

 

3、代码演示：

SpringContextUtil.java工具类

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

import java.util.Locale;

/**
 * @author yanghao
 * @Description:
 * @date 2018/12/21 16:57
 */
//spring 中通过ApplicationContext getBean获取注入对象, 必须在需要注入之前（被依赖）
public class SpringContextUtil implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    /**
     * 实现ApplicationContextAware接口的context注入函数, 将其存入静态变量.
     */
    @Override
    public void setApplicationContext(ApplicationContext context) throws BeansException {
        SpringContextUtil.applicationContext = context;
    }

    /**
     * 取得存储在静态变量中的ApplicationContext.
     */
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    /**
     * 获取对象
     * 这里重写了bean方法，起主要作用
     * @param beanName
     * @return Object 一个以所给名字注册的bean的实例
     * @throws BeansException
     * 从静态变量ApplicationContext中取得Bean, 自动转型为所赋值对象的类型.
     */
    public static Object getBean(String beanName) throws BeansException{
        return applicationContext.getBean(beanName);
    }

    public static Object getMessage(String key) {
        return applicationContext.getMessage(key, null, Locale.getDefault());
    }


    /**
     * 清除applicationContext静态变量.
     */
    public static void cleanApplicationContext() {
        applicationContext = null;
    }

    private static void checkApplicationContext() {
        if (applicationContext == null) {
            throw new IllegalStateException("applicaitonContext未注入");
        }
    }

}

线程注入：

import com.chargedot.server.producerdemo.service.PrintService;
import com.chargedot.server.producerdemo.utils.SpringContextUtil;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;


/**
 * @author yanghao
 * @Description:
 * @date 2018/12/21 17:22
 */

public class Event implements Runnable{

    KafkaTemplate kafkaTemplate = (KafkaTemplate) SpringContextUtil.getBean("kafkaTemplate");

   // PrintService printService = (PrintService) SpringContextUtil.getBean("printService"); //获取bean实例

    @Override
    public void run() {
       kafkaTemplate.send(消息);
    }

}

启动类：

import com.chargedot.platformservice.util.SpringContextUtil;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.context.ApplicationContext;

@SpringBootApplication
@EnableCircuitBreaker
@EnableEurekaClient
public class CommunicateAdapterServiceApplication {

    public static void main(String[] args) {
        ApplicationContext context = SpringApplication.run(CommunicateAdapterServiceApplication.class, args);
        new SpringContextUtil().setApplicationContext(context);  //获取bean

    }

}

如果你也有和我一样的问题，不妨试试这个。