Spring Boot: How to retrieve the username by user_id? - mysql

Question

I have already connected my springboot to MySQL database. I want to display the username when user_id is specified in the HTTP request. e.g. http://8080/user/1 must display the name of the user with user_id 1.
The table contains attributes as:
| Integer user_id; | String username; | String fathername; | String mothername;
I have already tried this code in by Controller class but i does not seem to be working
#RequestMapping("/{userid}")
#ResponseBody
public String getById(Integer userid) {
String name="";
try {
Optional<Persondetails> persondetails=persondetailsRepository.findById(personid);
name = String.valueOf(userdetails.getName());
}
catch (Exception ex) {
return "Name not found";
}
return "The Name of the user is : " + name;
}
my repository code:
import java.util.List;
import java.util.Optional;
public interface UserdetailsRepository extends JpaRepository<Userdetails, Integer> {
public Optional<Userdetails> findById(Integer userid);
}
It says getName() is undefined for the type Optional
But i have defined it in Userdetails class
public class Userdetails {
#Id
#GeneratedValue
#Column(name="user_id")
private Integer userid;
#Column(name="name")
private String name;
#Column (name="fathers_name")
private String fathersname;
#Column(name="mothers_name")
private String mothersname;
public Userdetails() {
}
public Integer getUserid() {
return userid;
}
public void setUserid(Integer userid) {
this.userid = userid;
}
public String getName() {
return name;
}
public void setname(String name) {
this.name = name;
}
public String getFathersname() {
return fathersname;
}
public void setFathersname(String fathersname) {
this.fathersname = fathersname;
}
public void setMothersname(String mothersname) {
this.mothersname = mothersname;
}
public String getMothersname() {
return mothersname;
}
}

Answer 1

It's missing the method type GET, you can do by two options:
#RequestMapping(value = "/{id}", method = RequestMethod.GET)
public User findOne(#PathVariable("id") int id){
return userService.findById(id);
}
OR
#GetMapping("/{id}")
public String getString(#PathVariable("id") int id) {
return "Helloworld";
}
Spring boot Connect with Mysql and get Data.
application.properties
server.contextPath=/demo-user
spring.datasource.url=jdbc:mysql://localhost:3306/testdb
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
*Controller.Java
#RequestMapping({"/users"})
public class UserController {
#Autowired
private UserService userService;
#GetMapping(path = {"/{id}"})
public User findOne(#PathVariable("id") int id){
return userService.findById(id);
}
}
UserService.java
public interface UserService {
User findById(int id);
}
UserServiceImpl.java
#Service
public class UserServiceImpl implements UserService {
#Autowired
private UserRepository repository;
#Override
public User findById(int id) {
return repository.findOne(id);
}
}
UserRepository .java
public interface UserRepository extends Repository<User, Integer> {
User findOne(int id);
}
User.java
#Entity
#Table(name = "user")
public class User {
#Id
#Column
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;
#Column
private String firstName;
#Column
private String lastName;
#Column
private String email;
//setter and getter
}
Make request from browser or application.
http://localhost:8080/demo-user/users/1