The SSM project can be started normally, but the webpage cannot be accessed, an error 404 is reported, and the console: Initializing Spring DispatcherServlet'dispatcherServlet'.

The SSM project can be started normally but the webpage cannot be accessed. After opening the webpage, an error 404

console output is reported :

2020-11-20 11:10:45.638  INFO 2780 --- [nio-8181-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
2020-11-20 11:10:45.638  INFO 2780 --- [nio-8181-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2020-11-20 11:10:45.639  INFO 2780 --- [nio-8181-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 1 ms

After reading some articles on the Internet, I think there should be a problem with the mapper layer. I wrote these two annotations in the main program.

@MapperScan(“com...dao”)
@ComponentScan(“com...entity”)

And also written in the mapper file

@Repository("***mapper")
@Mapper

I just started to learn, I haven't understood the principles inside, it seems that there is a scanning conflict... or something

solution

1. Deleted annotations program entry function @MapperScan("com.**.**.dao") @ComponentScan("com.**.**.entity"),
   the program entry function at only write the@SpringBootApplication
2. Also delete the annotations of the mapper file and @Repository("***mapper")only keep it@Mapper
3. In application.properties file written into

#对应mapper的.xml的位置
mybatis.mapper-locations=classpath:com.**.**.dao/*.xml
#对应实体类的位置
mybatis.type-aliases-package=com.**.**.entity

OK, mine is solved here, I hope it helps you.

: It seems to be very simple, I tossed for two days to solve it.
: Sure enough, you still have to learn the principles clearly!