在普通类中使用mapper、service_使用了mapper注解的接口类无法通过applicationcontext获取-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_42067668/article/details/97031431

本文介绍了一种在Spring框架中创建实用工具类的方法，该类实现了ApplicationContextAware接口，用于便捷地获取Spring容器中的Bean实例。此外，还展示了如何在具体业务场景中应用此工具类来调用Mapper接口的方法。

首先需要新建一个类，实现 ApplicationContextAware 接口。

@Component  
public class SpringUtils implements ApplicationContextAware {  
 
    private static ApplicationContext applicationContext = null;  
 
    @Override  
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {  
        if(SpringUtils.applicationContext == null){  
            SpringUtils.applicationContext  = applicationContext;  
        }  
    }  
 
 
    //获取applicationContext  
    public static ApplicationContext getApplicationContext() {  
        return applicationContext;  
    }  
 
    //通过name获取 Bean.  
    public static Object getBean(String name){  
        return getApplicationContext().getBean(name);  
    }  
 
    //通过class获取Bean.  
    public static <T> T getBean(Class<T> clazz){  
        return getApplicationContext().getBean(clazz);  
    }  
 
    //通过name,以及Clazz返回指定的Bean  
    public static <T> T getBean(String name,Class<T> clazz){  
        return getApplicationContext().getBean(name, clazz);  
    }  
 
}

第二步，定义

    private ApplicationContext applicationContext = SpringUtils.getApplicationContext();

    private UserMapper userMapper = applicationContext.getBean(UserMapper.class);

3.第三步使用

   public JSONObject TransChangeDevUserMapToObject(Map<String,Object> map){
            Object stuid = map.get("DEV_RESP_USER");
            Long stu_ID = ObjectTodLong(stuid);
            String name = userMapper.find_name_By_ID(stu_ID);
            map.put("DEV_RESP_USER",name);
            Object stuid2 = map.get("RECEIVE_USER");
            Long stu_ID2 = ObjectTodLong(stuid2);
            String name2 = userMapper.find_name_By_ID(stu_ID2);
            map.put("RECEIVE_USER",name2);
        return transToJsonObject(map);
    }