package com.ggurys.springbootwebservice.domain.user;

import com.ggurys.springbootwebservice.domain.BaseTimeEntity;
import lombok.Builder;
import lombok.Getter;
import lombok.NoArgsConstructor;
import javax.persistence.*;
@Getter
@NoArgsConstructor
@Entity
public class User extends BaseTimeEntity{
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;

  @Column(nullable = false)
  private String name;

  @Column(nullable = false)
  private String email;

  @Column
  private String picture;

  @Enumerated(EnumType.STRING)
  @Column(nullable = false)
  private Role role;

  @Builder
  public User(String name, String email, String picture, Role role) {
    this.name = name;
    this.email = email;
    this.picture = picture;
    this.role = role;
  }

  public User update(String name, String picture) {
    this.name = name;
    this.picture = picture;
    return this;
  }

  public String getRoleKey() {
    return this.role.getKey();
  }
}

private final String key;
private final String title;

## **\-UserRepository-**
User의 CRUD를 책입질 UserRepository 생성

```java
package com.ggurys.springbootwebservice.domain.user;

import org.springframework.data.jpa.repository.JpaRepository;
import java.util.Optional;

public interface UserRepository extends JpaRepository<User,Long> {
    Optional<User> findByEmail(String email);
}

package com.ggurys.springbootwebservice.config.auth;

import com.ggurys.springbootwebservice.domain.user.Role;
import lombok.RequiredArgsConstructor;
import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;

@RequiredArgsConstructor
@EnableWebSecurity // 1.
public class SecurityConfig extends WebSecurityConfigurerAdapter {

  private final CustomOAuth2UserService customOAuth2UserService;

  @Override
  protected void configure(HttpSecurity http) throws Exception {
    http
            .csrf().disable().headers().frameOptions().disable() // 2.
            .and()
            .authorizeRequests() // 3.
            .antMatchers("/", "/view/**", "/css/**", "/images/**", "/js/**", "/h2-console/**", "/profile").permitAll().antMatchers("/api/v1/**").hasRole(Role.USER.name()) // 4.
            .anyRequest().authenticated() // 5.
            .and()
            .logout()
            .logoutSuccessUrl("/") // 6.
            .and()
            .oauth2Login() // 7.
            .userInfoEndpoint() // 8.
            .userService(customOAuth2UserService); // 9.
  }
}

package com.ggurys.springbootwebservice.config.auth;

import com.ggurys.springbootwebservice.config.auth.dto.OAuthAttributes;
import com.ggurys.springbootwebservice.config.auth.dto.SessionUser;
import com.ggurys.springbootwebservice.domain.user.User;
import com.ggurys.springbootwebservice.domain.user.UserRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.oauth2.client.userinfo.DefaultOAuth2UserService;
import org.springframework.security.oauth2.client.userinfo.OAuth2UserRequest;
import org.springframework.security.oauth2.client.userinfo.OAuth2UserService;
import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
import org.springframework.security.oauth2.core.user.DefaultOAuth2User;
import org.springframework.security.oauth2.core.user.OAuth2User;
import org.springframework.stereotype.Service;

import javax.servlet.http.HttpSession;
import java.util.Collections;

@Service
@RequiredArgsConstructor
public class CustomOAuth2UserService implements OAuth2UserService<OAuth2UserRequest, OAuth2User> {
  private final UserRepository userRepository;
  private final HttpSession httpSession;

  @Override
  public OAuth2User loadUser(OAuth2UserRequest userRequest) throws OAuth2AuthenticationException {
    OAuth2UserService<OAuth2UserRequest, OAuth2User> delegate = new DefaultOAuth2UserService();
    OAuth2User oAuth2User = delegate.loadUser(userRequest);

    // OAuth2 서비스 id (구글, 카카오, 네이버)
    String registrationId = userRequest.getClientRegistration().getRegistrationId(); // 1.
    // OAuth2 로그인 진행 시 키가 되는 필드 값(PK)
    String userNameAttributeName = userRequest.getClientRegistration().getProviderDetails().getUserInfoEndpoint().getUserNameAttributeName(); // 2.

    // OAuth2UserService
    OAuthAttributes attributes = OAuthAttributes.of(registrationId, userNameAttributeName, oAuth2User.getAttributes()); // 3.
    User user = saveOrUpdate(attributes);
    httpSession.setAttribute("user", new SessionUser(user)); // 4. SessionUser (직렬화된 dto 클래스 사용) 

    return new DefaultOAuth2User(Collections.singleton(new SimpleGrantedAuthority(user.getRoleKey())),
            attributes.getAttributes(),
            attributes.getNameAttributeKey());
  }

  // 유저 생성 및 수정 서비스 로직
  private User saveOrUpdate(OAuthAttributes attributes){
    User user = userRepository.findByEmail(attributes.getEmail())
            .map(entity -> entity.update(attributes.getName(), attributes.getPicture()))
            .orElse(attributes.toEntity());
    return userRepository.save(user);
  }
}

package com.ggurys.springbootwebservice.config.auth.dto;

import com.ggurys.springbootwebservice.domain.user.Role;
import com.ggurys.springbootwebservice.domain.user.User;
import lombok.Builder;
import lombok.Getter;
import java.util.Map;

@Getter
public class OAuthAttributes {
    private Map<String, Object> attributes; // OAuth2 반환하는 유저 정보 Map
    private String nameAttributeKey;
    private String name;
    private String email;
    private String picture;

    @Builder
    public OAuthAttributes(Map<String, Object> attributes, String nameAttributeKey, String name, String email, String picture) {
        this.attributes = attributes;
        this.nameAttributeKey = nameAttributeKey;
        this.name = name;
        this.email = email;
        this.picture = picture;
    }
    
    // 1 
    public static OAuthAttributes of(String registrationId, String userNameAttributeName, Map<String, Object> attributes){
        // 여기서 네이버와 카카오 등 구분 (ofNaver, ofKakao)

        return ofGoogle(userNameAttributeName, attributes);
    }


    private static OAuthAttributes ofGoogle(String userNameAttributeName, Map<String, Object> attributes) {
        return OAuthAttributes.builder()
                .name((String) attributes.get("name"))
                .email((String) attributes.get("email"))
                .picture((String) attributes.get("picture"))
                .attributes(attributes)
                .nameAttributeKey(userNameAttributeName)
                .build();
    }
    
    // 2.
    public User toEntity(){
        return User.builder()
                .name(name)
                .email(email)
                .picture(picture)
                .role(Role.GUEST) // 기본 권한 GUEST
                .build();
    }

}

package com.ggurys.springbootwebservice.config.auth.dto;
import com.ggurys.springbootwebservice.domain.user.User;
import lombok.Getter;
import java.io.Serializable;
/**
 * 직렬화 기능을 가진 User클래스
 */
@Getter
public class SessionUser implements Serializable {
    private String name;
    private String email;
    private String picture;

    public SessionUser(User user){
        this.name = user.getName();
        this.email = user.getEmail();
        this.picture = user.getPicture();
    }
}

<h1>스프링 부트로 시작하는 웹서비스</h1>
<div class="col-md-12">
    <div class="row">
        <div class="col-md-6">
            <a href="/posts/save" role="button" class="btn btn-primary">글 등록</a>
            {{#userName}} <!-- 1. -->
                Logged in as: <span id="user">{{userName}}</span>
                <a href="/logout" class="btn btn-info active" role="button">Logout</a>  <!-- 2. -->
            {{/userName}}
            {{^userName}} <!-- 3. -->
                <a href="/oauth2/authorization/google" class="btn btn-success active" role="button">Google Login</a>  <!-- 4. -->
            {{/userName}}
        </div>
    </div>
</div>

<br/>
<!--목록 출력 영역-->

@RequiredArgsConstructor
@Controller
public class IndexController {

  private final PostsService postsService;
  private final HttpSession httpSession;

  @GetMapping("/")
  public String index(Model model){ // model 서버 템플릿 엔진에서 사용할 수 있는 객체를 저장 (postsService.findAllDesc()로 가져온 결과를 posts로 index.mustache에 전달)
    model.addAttribute("posts", postsService.findAllDesc());

    SessionUser user = (SessionUser) httpSession.getAttribute("user");

    if(user != null){
      model.addAttribute("userName", user.getName());
    }
    return "index";
  }
}