모든 기능을 갖춘 온라인 음악 학습 애플리케이션을 Java로 구현하는 논리적 프로세스

@EnableWebSecurity
public class MySecurityConfig extends WebSecurityConfigurerAdapter {
   @Autowired
   private MyUserDetailsService userDetailsService;

   @Override
   protected void configure(AuthenticationManagerBuilder auth) throws Exception {
       auth.userDetailsService(userDetailsService).passwordEncoder(passwordEncoder());
   }

   @Override
   protected void configure(HttpSecurity http) throws Exception {
       http
               .csrf().disable()
               .authorizeRequests()
                   .antMatchers("/css/**", "/js/**", "/images/**", "/music/**").permitAll()
                   .antMatchers("/register", "/login", "/error").permitAll()
                   .antMatchers("/home", "/app", "/admin/**").hasRole("USER")
                   .anyRequest().authenticated()
               .and()
                   .formLogin()
                   .loginPage("/login")
                   .defaultSuccessUrl("/home")
                   .failureUrl("/login?error")          
                   .permitAll()
               .and()
                   .logout()
                   .logoutSuccessUrl("/login")
                   .permitAll();
   }

   @Bean
   public PasswordEncoder passwordEncoder() {
       return new BCryptPasswordEncoder();
   }
   
}

public class SpotifyAPI {
   private HttpClient httpClient;
   private String clientId;
   private String clientSecret;

   public SpotifyAPI(HttpClient httpClient, String clientId, String clientSecret) {
       this.httpClient = httpClient;
       this.clientId = clientId;
       this.clientSecret = clientSecret;
   }

   public String searchTrack(String searchQuery) throws IOException {
       URIBuilder uriBuilder = new URIBuilder("https://api.spotify.com/v1/search")
               .addParameter("q", searchQuery)
               .addParameter("type", "track")
               .addParameter("limit", "50");

       HttpGet httpGet = new HttpGet(uriBuilder.build());
       httpGet.setHeader("Content-Type", "application/x-www-form-urlencoded");
       httpGet.setHeader("Authorization", "Bearer " + getToken());
       HttpResponse response = httpClient.execute(httpGet);

       BufferedReader rd = new BufferedReader(
               new InputStreamReader(response.getEntity().getContent()));

       StringBuffer result = new StringBuffer();
       String line = "";
       while ((line = rd.readLine()) != null) {
           result.append(line);
       }

       return result.toString();
   }

   private String getToken() throws IOException {
       HttpPost httpPost = new HttpPost("https://accounts.spotify.com/api/token");
       String authHeaderString = clientId + ":" + clientSecret;
       String encodedAuthHeader = Base64.getEncoder().encodeToString(authHeaderString.getBytes());

       httpPost.setHeader("Authorization", "Basic " + encodedAuthHeader);
       httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded");
       httpPost.setEntity(new StringEntity("grant_type=client_credentials"));

       HttpResponse response = httpClient.execute(httpPost);

       BufferedReader rd = new BufferedReader(
               new InputStreamReader(response.getEntity().getContent()));

       StringBuffer result = new StringBuffer();
       String line = "";
       while ((line = rd.readLine()) != null) {
           result.append(line);
       }

       String accessToken = JsonPath.read(result.toString(), "$.access_token");

       return accessToken;
   }
}

@Controller
public class HomeController {
   @Autowired
   private MusicRepository musicRepository;

   @GetMapping("/")
   public String index() {
       return "index";
   }

   @GetMapping("/search")
   public String search(Model model, @RequestParam("q") String query) {
       SpotifyAPI spotifyAPI = new SpotifyAPI();
       String searchResults = spotifyAPI.searchTrack(query);

       List<Music> musicList = new ArrayList<>();

       try {
           JSONObject jsonObject = new JSONObject(searchResults);
           JSONArray tracks = jsonObject.getJSONObject("tracks").getJSONArray("items");

           for (int i = 0; i < tracks.length(); i++) {
               JSONObject track = (JSONObject) tracks.get(i);

               Music music = new Music();
               music.setName(track.getString("name"));
               music.setArtist(track.getJSONArray("artists").getJSONObject(0).getString("name"));
               music.setAlbum(track.getJSONObject("album").getString("name"));
               music.setUrl(track.getJSONObject("external_urls").getString("spotify"));

               musicList.add(music);
           }
       } catch (JSONException e) {
           e.printStackTrace();
       }

       musicRepository.saveAll(musicList);

       model.addAttribute("musicList", musicList);

       return "search";
   }
}

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
   <meta charset="utf-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>Music Player - Search</title>
   <link rel="stylesheet" type="text/css" th:href="@{/css/site.css}" />
</head>
<body>
   <form th:action="@{/search}" method="get">
       <input type="text" name="q" placeholder="Search for music..." />
       <input type="submit" value="Search" />
   </form>

   <div class="card-deck">
       <div class="row">
           <div th:each="music : ${musicList}" class="col-md-4 col-sm-6 col-xs-12">
               <div class="card mb-4 box-shadow">
                   <div class="card-header">
                       <h4 class="my-0 font-weight-normal" th:text="${music.name}" /></h4>
                   </div>
                   <div class="card-body">
                       <p class="card-text" th:text="${music.artist + ' - ' + music.album}" />
                       <audio controls th:src="${music.url}" />
                   </div>
               </div>
           </div>
       </div>
   </div>

</body>
</html>