There was an unexpected error (type=Not Found, status=404). - Spring Java

Question

I have this service in github https://github.com/felloz/personsService The application compile with no errors but when im trying to access the route http://localhost:8080/demo/persons Im getting this error:

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Mon May 11 14:55:30 VET 2020
There was an unexpected error (type=Not Found, status=404).
No message available

The compile message:

 .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.2.7.RELEASE)

2020-05-11 15:05:55.576  INFO 10476 --- [           main] com.example.demo.DemoApplication         : Starting DemoApplication on lserrano-PC with PID 10476 (C:\JAVA\Eclipse Projects\demo\target\classes started by lserrano in C:\JAVA\Eclipse Projects\demo)
2020-05-11 15:05:55.592  INFO 10476 --- [           main] com.example.demo.DemoApplication         : No active profile set, falling back to default profiles: default
2020-05-11 15:05:58.173  INFO 10476 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2020-05-11 15:05:58.198  INFO 10476 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2020-05-11 15:05:58.198  INFO 10476 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.34]
2020-05-11 15:05:58.386  INFO 10476 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2020-05-11 15:05:58.387  INFO 10476 --- [           main] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2685 ms
2020-05-11 15:05:58.857  INFO 10476 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
2020-05-11 15:05:59.362  INFO 10476 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2020-05-11 15:05:59.377  INFO 10476 --- [           main] com.example.demo.DemoApplication         : Started DemoApplication in 4.578 seconds (JVM running for 5.433)
2020-05-11 15:06:14.712  INFO 10476 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
2020-05-11 15:06:14.712  INFO 10476 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2020-05-11 15:06:14.727  INFO 10476 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 15 ms

You can check the code in the github repo, Im new with Sprong any help will be appreciated, im using NetBeans as IDE.

After adding server.servlet.context-path=/demo

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.2.7.RELEASE)

2020-05-11 17:26:54.336  INFO 9144 --- [           main] com.example.demo.DemoApplication         : Starting DemoApplication on lserrano-PC with PID 9144 (C:\JAVA\Eclipse Projects\demo\target\classes started by lserrano in C:\JAVA\Eclipse Projects\demo)
2020-05-11 17:26:54.336  INFO 9144 --- [           main] com.example.demo.DemoApplication         : No active profile set, falling back to default profiles: default
2020-05-11 17:26:56.926  INFO 9144 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2020-05-11 17:26:56.957  INFO 9144 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2020-05-11 17:26:56.957  INFO 9144 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.34]
2020-05-11 17:26:57.160  INFO 9144 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/demo]   : Initializing Spring embedded WebApplicationContext
2020-05-11 17:26:57.160  INFO 9144 --- [           main] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2715 ms
2020-05-11 17:26:57.612  INFO 9144 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
2020-05-11 17:26:58.111  INFO 9144 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path '/demo'
2020-05-11 17:26:58.111  INFO 9144 --- [           main] com.example.demo.DemoApplication         : Started DemoApplication in 4.591 seconds (JVM running for 5.464)
2020-05-11 17:27:14.361  INFO 9144 --- [nio-8080-exec-2] o.a.c.c.C.[Tomcat].[localhost].[/demo]   : Initializing Spring DispatcherServlet 'dispatcherServlet'
2020-05-11 17:27:14.362  INFO 9144 --- [nio-8080-exec-2] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2020-05-11 17:27:14.379  INFO 9144 --- [nio-8080-exec-2] o.s.web.servlet.DispatcherServlet        : Completed initialization in 17 ms

Answer 1

If you don't want to use Jpa, following changes would be needed :

Context Path should be set as:

server.servlet.context-path=/demo

DemoApplication Class (correcting base package):

@SpringBootApplication
@ComponentScan(basePackages = {"com.example"})
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

You need to provide the implementation for your Repositoory:

import java.util.ArrayList;
import java.util.List;
import org.springframework.stereotype.Repository;

@Repository
public class PersonRepository{
    public List<Person> findAll(){
        List<Person> list = new ArrayList<>();
        Person person = new Person();
        person.setId(10001);
        person.setName("Name");
        person.setLastname("LastName");
        list.add(person);
        return list; 
    }
}

To work with MySQL DB and SpringBoot , you can find many example on web. Please follow that. Example : SpringBootMySQLExample

Answer 2

after spring 2 , context path configuration has been changed ;

server.servlet.context-path=/demo

And then try http://localhost:8080/demo/persons

Answer 3

you have @RequestMapping({"/persons"}) in your controller, so try this link http://localhost:8080/persons without demo