SpringBoot Course 🔥

By UltrasDzCoder You Can see full course here

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Install SpringBoot :

1. You need Install java , InteliJ Idea
2. Go To Spring initializer here
3. add spring web , postgres driver.
4. Generate Prject & Download it .
5. Extract the project with winrar.
6. now open it with intliJ IDEA .

---

First App :

1. Add annotation @RestController to MainClass .

2. Create new Method hello()

        @GetMapping
        public String  hello(){
           return "<h1>hello udc from spring boot</h1>";
        }
   

---

Add Json Data :

1. replace String type to List (from java.util)

2. replace returning to List.of("html","css"....)

3. result :

          @GetMapping
          public List<String>  hello(){
            return List.of("hello", "udc" ,"from" ,"spring" ,"boot");
           }
   

---

Create Users Model :

1. Create new package name users

2. Create into users class file Users

3. initialize private propreties id:Long,name:String,phone:String

4. add empty contracture Alt+insert

5. add contracture for all props

6. add contracture without id

7. add setters & getters for all props

8. add to string contracture

          public class Users {
              private Long id;
                 private String name;
                 private String phone;
   
                 public Users() {
                 }
   
                 public Users(Long id, String name, String phone) {
                 this.id = id;
                 this.name = name;
                 this.phone = phone;
                 }
   
                 public Users(String name, String phone) {
                 this.name = name;
                 this.phone = phone;
                 }
   
                 public Long getId() {
                 return id;
                 }
   
                 public void setId(Long id) {
                 this.id = id;
                 }
   
                 public String getName() {
                 return name;
                 }
   
                 public void setName(String name) {
                 this.name = name;
                 }
   
                 public String getPhone() {
                 return phone;
                 }
   
                 public void setPhone(String phone) {
                 this.phone = phone;
                 }
   
                 @Override
                 public String toString() {
                 return "Users{" +
                 "id=" + id +
                 ", name='" + name + '\'' +
                 ", phone='" + phone + '\'' +
                 '}';
                 }
                 }
   

9. Now replace string to Users like that

                 @GetMapping
                    public List<Users> hello (){
                        return List.of(
                              new Users(
                                        1L,
                                        "Cyrus Burt",
                                        "1-456-842-7528"
                                       ),
                               new Users(
                                        2L,
                                        "Ethan Simpson",
                                        "(493) 778-2015"
                                         )
                                     );
                    }
   

---

Create Controller :

1. Create new class File named UsersController

2. Remove @RestController from mainApp with entire hello()

3. past the hello in UsersController

4. Add to class Controller & request mapping

   @RestController @RequestMapping(path="api/users") public class UsersController {

   @GetMapping public List getUsers (){ return List.of( new Users( 1L, "Cyrus Burt", "1-456-842-7528" ), new Users( 2L, "Ethan Simpson", "(493) 778-2015" ) ); }

---

Connect To db :

1. in Users add

   import javax.persistence.*;
   
   @Entity
   @Table
   

with :

  @Id
  @SequenceGenerator(
     name = "users_sequence",
     sequenceName = "users_sequence",
     allocationSize = 1
  )

  @GeneratedValue(
        strategy = GenerationType.SEQUENCE,
        generator = "users_sequence"
  )

2. now install postgreSql

   1. add bin (postgresql) to path

   2. open git or cmd

   3. type psql -U postgres

   4. type password (0000)

   5. type ! cls to cleaning window

   6. type \l to show databases

   7. type \c to redirect of this DB

   8. type \d to display (You can display with )

   9. add

       CREATE DATABASE usersdata;
      

3. in resource/application.properties :

     spring.datasource.url=jdbc:postgresql://localhost:5432/usersdata
     spring.datasource.username=postgres
     spring.datasource.password=0000
     spring.jpa.hibernate.ddl-auto=create-drop spring.jpa.show-sql=true
     spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect
     spring.jpa.properties.hibernate.format_sql=true
   

---

Database Layer :

1. in users folder Create new interface UsersRepository

2. now write in UsersRepository

   @Repository
   public interface UsersRepository extends JpaRepository<Users,Long> {
   
   
   }
   

3. in UsersService :

   private final UsersRepository usersRepository;
   
   @Autowired
   public UsersService(UsersRepository usersRepository) {
   this.usersRepository = usersRepository;
   }
      
   public List<Users> getUsers (){
   return usersRepository.findAll();
   }
   

---

Inserting Dommy data :

1. Create UsersConfig Class
2. past this

@Configuration public class UsersConfig {

@Bean
CommandLineRunner commandLineRunner(UsersRepository repository) {
    return args -> {
        Users Cyrus = new Users(

                "Cyrus Burt",
                "1-456-842-7528"
        );

        Users Ethan = new Users(

                "Ethan Simpson",
                "(493) 778-2015"
        );

        repository.saveAll(
                List.of(Cyrus,
                        Ethan)
        );

    };
 }
}

---

Post in body :

1. in UsersController :

   @PostMapping
   public void registerUser( @RequestBody Users user){
   usersService.addUser(user);
   }
   

2. in UsersService :

   // POST: /api/users
   public void addUser(Users user) {
      System.out.println(user);
   }
   

3. send data in postman with row

---

Delete Data :

1. in UsersController

    @DeleteMapping(path= "{userId}")
    public void deleteUser(@PathVariable("userId") Long userId){
      usersService.removeUser(userId);
    }
   

2. in UsersService

   public void removeUser(Long userId) {
   
      boolean exists = usersRepository.existsById(userId);
   
      if (!exists) throw new IllegalStateException("Not Found");
   
       usersRepository.deleteById(userId);
   }
   

3. Now in postman /api/users/id

---

Update Data :

1. in UsersController

    @PutMapping(path = "{userId}")
    public void updateUser(
     @PathVariable("userId") Long userId,
     @RequestParam(required = false) String name,
     @RequestParam(required = false) String phone) {
   
        usersService.updateUser(userId,name,phone);
    }
   

2. in UsersService

   // PUT: /api/users @Transactional public void updateUser(Long userId, String name, String phone) { Users user = usersRepository.findById(userId).orElseThrow( () -> new IllegalStateException("user id :" + userId + "dont exists") );

    if (name != null
            && name.length() > 0 &&
            !Objects.equals(user.getName(),name)
   
    ) {
        user.setName(name);
    }
   
    if (phone != null
            && phone.length() > 0 &&
            !Objects.equals(user.getPhone(),phone)
   
    ) {
        user.setPhone(phone);
    }
   

   }