ApplicationContextAware的应用

package com.ymdd.galaxy.comment.core.comment.service.impl;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Service;

import java.util.Map;
/**  
 *  
 * 获取spring容器，以访问容器中定义的其他bean 
 * 类的名称上增加@Component注解，这样spring初始化的时候才能把这个类纳入到IOC容器，然后就可以在任意地方使用这个工具类了
 * @author  
 */
//一定要加注解Service或者Component，不然spring容器初始化的时候会通过注解来扫描，导致扫描不到
@Service
public class FmcSpringContext implements ApplicationContextAware {
    private static ApplicationContext applicationContext;
    //setApplicationContext方法就是把 ApplicationContext容器的值给你注入进来，实例化后的值注入进来，
    //ApplicationContext容器:所有spring配置文件中的东西和注解自动注入的东西集合

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

    }

    /**
     * 获取applicationContext对象
     *
     * @return
     */
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    /**
     * 根据bean的id来查找对象
     *
     * @param id
     * @return
     */
    public static Object getBeanById(String id) {
        return applicationContext.getBean(id);
    }

    /**
     * 根据bean的class来查找对象
     *
     * @param c
     * @return
     */
    public static <T> T getBeanByClass(Class c) {
        Object obj = applicationContext.getBean(c);
        if (obj != null) {
            return (T) obj;
        } else {
            return null;
        }
    }

    /**
     * 根据bean的class来查找所有的对象(包括子类)
     *
     * @param c
     * @return
     */
    public static Map getBeansByClass(Class c) {
        return applicationContext.getBeansOfType(c);
    }
}

package com.ymdd.galaxy.comment.core.comment.service.impl;

import com.ymdd.galaxy.comment.core.comment.service.ICommentDetailService;
import com.ymdd.galaxy.comment.entity.comment.model.CommentDetail;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Component
public class FmcInitContext {

    @Autowired
    FmcSpringContext springContextUtils;

    private Map<Integer, ICommentDetailService> traceStrategys = new HashMap<>();

    public ICommentDetailService buildTraceStrategy(Integer orderChanne) {
        return traceStrategys.get(orderChanne);
    }

    @PostConstruct
    public List<CommentDetail> initTraceStrategyMap() {
        traceStrategys.put(23, springContextUtils.getBeanByClass(CommentDetailServiceImpl.class));
        ICommentDetailService commentDetailService = springContextUtils.getBeanByClass(CommentDetailServiceImpl.class);
        return commentDetailService.queryCommentListDayByCommentedTime();
    }

}

@PostConstruct在所有注解类初始化完成之后会调用被它标记的方法