初学SSM+mybatis单元测试遇到的问题，dao注入后为null
Dao层注入失败，查看后，发现注解都写的无误，经朋友的指点，
在测试类上加了一句“@RunWith(SpringJUnit4ClassRunner.class)  
@ContextConfiguration(locations={“classpath:spring/applicationContext-tx.xml”,“classpath:spring/applicationContext-service.xml”,“classpath:spring/applicationContext-dao.xml”})” 经测试，Dao可以注入，不再为null ---------------------  作者：旅途上的背包客  来源：CSDN  原文：https://blog.csdn.net/u012799877/article/details/83056657?utm_source=copy  版权声明：本文为博主原创文章，转载请附上博文链接！
 

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:spring/applicationContext-tx.xml","classpath:spring/applicationContext-service.xml","classpath:spring/applicationContext-dao.xml"})
public class TaskInfoTest {
    @Autowired
 TaskService taskService;
    @Test
 public void test(){
        TaskInfo taskInfo = new TaskInfo();
        taskInfo.setTid(2);
        taskInfo.setTname("taskname");
        taskInfo.setStatus("成功");
        taskInfo.setBtime("2018-10-12");
        taskInfo.setEtime("2018-10-15");
        taskService.add(taskInfo);
    }
}