如何获取Mapper

一.遇到的情况说明

                环境 1.Spring Boot 2.Mapper全部使用注解

1.   反射的类需要 使用到mapper，情况如下

2. //反射实体类com.test.Process
   Class<?> clazz = Class.forName("com.test.Process");
   // 调用任务
   Method process = clazz.getMethod("tetsMethod", Integer.class, String.class);
   Boolean next = (Boolean) process.invoke(clazz.newInstance(), 0,"str");
   

   //被反射的类Process
   @Component
   public class Process implements HandleTask {
   
      //此时 使用该方法获取不到testMapper 在执行过程中会出现空指针异常
      @Autowired
      TestMapper testMapper;
   
   
      public boolean testMethod(int i,String str){
           testMapper.query(i,str);
      }
   
   }

    

二.解决方法

1. 新建一个静态类用来保存 上下文

2. /**
    * @author LEI
    * Created by LEI on 2019/9/25.
    */
   public class SpringBootCtx {
       private static ConfigurableApplicationContext applicationContext;
   
       public static void setApplicationContext(ConfigurableApplicationContext applicationContext) {
           SpringBootCtx.applicationContext = applicationContext;
       }
   
       public static ConfigurableApplicationContext getApplicationContext() {
           return applicationContext;
       }
   
       public static ConfigurableListableBeanFactory getBeanFactory(){
           return  applicationContext.getBeanFactory();
       }
   }
   

       2. 在spirng boot启动时保存上下文 

1. public static void main(String[] args) {
   		ConfigurableApplicationContext applicationContext =SpringApplication.run(CloudhomeApplication.class, args);
   		SpringBootCtx.setApplicationContext(applicationContext);
   	}

        3. 在使用时

1. //被反射的类Process
   @Component
   public class Process implements HandleTask {
   
      //此时 使用该方法获取不到testMapper 在执行过程中会出现空指针异常
      //@Autowired
      //TestMapper testMapper;
   
   
      public boolean testMethod(int i,String str){
           TestMapper testMapper = SpringBootCtx.getBeanFactory().getBean(TestMapper.class);
           testMapper.query(i,str);
      }
   
   }