refactor: MovieTimeRepository - findValidMovieTimes 네이티브 쿼리 -> JPQL로 변경

server/src/main/java/com/ticketing/server/global/exception/ErrorCode.java

@@ -19,6 +19,7 @@ public enum ErrorCode {
 
 	/* 404 NOT_FOUND : Resource 를 찾을 수 없음 */
 	EMAIL_NOT_FOUND(NOT_FOUND, "해당 이메일을 찾을 수 없습니다."),
+	MOVIE_NOT_FOUND(NOT_FOUND, "해당 제목의 영화를 찾을 수 없습니다."),
 	REFRESH_TOKEN_NOT_FOUND(NOT_FOUND, "리프레쉬 토큰을 찾을 수 없습니다."),
 
 	/* 409 CONFLICT : Resource 의 현재 상태와 충돌. 보통 중복된 데이터 존재 */

server/src/main/java/com/ticketing/server/global/security/WebSecurityConfig.java

@@ -54,6 +54,7 @@ public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
 			.antMatchers(HttpMethod.POST, "/api/auth/refresh").permitAll()
 			.antMatchers(HttpMethod.POST, "/api/users").permitAll()
 			.antMatchers("/api/movies/**").permitAll()
+			.antMatchers("/api/movieTimes/**").permitAll()
 			.antMatchers("/l7check").permitAll()
 			.antMatchers("/actuator/**").permitAll()
 			.antMatchers("/api/v3/", "/swagger-ui/**", "/swagger/", "/swagger-resources/**", "/v3/api-docs").permitAll()

server/src/main/java/com/ticketing/server/movie/application/MovieTimeController.java

@@ -0,0 +1,39 @@
+package com.ticketing.server.movie.application;
+
+import com.ticketing.server.movie.application.response.MovieTimeListResponse;
+import com.ticketing.server.movie.service.interfaces.MovieTimeService;
+import io.swagger.annotations.Api;
+import io.swagger.annotations.ApiOperation;
+import io.swagger.annotations.ApiParam;
+import java.time.LocalDate;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.format.annotation.DateTimeFormat;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.annotation.Validated;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/api/movieTimes")
+@Api(value = "MovieTime API", tags = {"Movie Time"})
+@RequiredArgsConstructor
+@Slf4j
+public class MovieTimeController {
+
+    private final MovieTimeService movieTimeService;
+
+    @GetMapping
+    @ApiOperation(value = "영화 시간표 조회")
+    @Validated
+    public ResponseEntity<MovieTimeListResponse> getMovieTimes(
+        @ApiParam(value = "영화 제목", required = true) @RequestParam String title,
+        @ApiParam(value = "상영 날짜", required = true) @RequestParam @DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate runningDate) {
+        return ResponseEntity.status(HttpStatus.OK).body(MovieTimeListResponse.from(movieTimeService.getMovieTimes(title, runningDate)));
+    }
+
+
+}

server/src/main/java/com/ticketing/server/movie/application/MovieTimesController.java

@@ -1,8 +0,0 @@
-package com.ticketing.server.movie.application;
-
-import org.springframework.web.bind.annotation.RestController;
-
-@RestController
-public class MovieTimesController {
-
-}

server/src/main/java/com/ticketing/server/movie/application/response/MovieListResponse.java

@@ -1,6 +1,5 @@
 package com.ticketing.server.movie.application.response;
 
-import com.fasterxml.jackson.annotation.JsonProperty;
 import com.ticketing.server.movie.service.dto.MovieDto;
 import io.swagger.annotations.ApiModelProperty;
 import java.util.List;
@@ -13,7 +12,6 @@ import lombok.Getter;
 public class MovieListResponse {
 
     @ApiModelProperty(value = "영화 제목")
-    @JsonProperty
     private List<MovieDto> movieDtos;
 
     public static MovieListResponse from(List<MovieDto> movieDtos) {

server/src/main/java/com/ticketing/server/movie/application/response/MovieTimeListResponse.java

@@ -0,0 +1,21 @@
+package com.ticketing.server.movie.application.response;
+
+import com.ticketing.server.movie.service.dto.MovieTimeDto;
+import io.swagger.annotations.ApiModelProperty;
+import java.util.List;
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
+public class MovieTimeListResponse {
+
+    @ApiModelProperty(value = "영화 시간표 정보")
+    private List<MovieTimeDto> movieTimeDtos;
+
+    public static MovieTimeListResponse from(List<MovieTimeDto> movieTimeDtos) {
+        return new MovieTimeListResponse(movieTimeDtos);
+    }
+
+}

server/src/main/java/com/ticketing/server/movie/domain/Movie.java

@@ -22,8 +22,4 @@ public class Movie extends AbstractEntity {
     @NotNull
     private Integer runningTime;
 
-    public MovieDto toDto() {
-        return new MovieDto(this.title);
-    }
-
 }

server/src/main/java/com/ticketing/server/movie/domain/MovieTime.java

@@ -1,7 +1,7 @@
 package com.ticketing.server.movie.domain;
 
 import com.ticketing.server.global.dto.repository.AbstractEntity;
-import java.time.LocalDate;
+import com.ticketing.server.movie.service.dto.MovieTimeDto;
 import java.time.LocalDateTime;
 import javax.persistence.Entity;
 import javax.persistence.JoinColumn;
@@ -11,7 +11,7 @@ import lombok.Getter;
 
 @Entity
 @Getter
-public class MovieTimes extends AbstractEntity {
+public class MovieTime extends AbstractEntity {
 
 	@NotNull
 	@ManyToOne
@@ -23,9 +23,6 @@ public class MovieTimes extends AbstractEntity {
 	@JoinColumn(name = "theater_id", referencedColumnName = "id", updatable = false)
 	private Theater theater;
 
-	@NotNull
-	private LocalDate runningDate;
-
 	@NotNull
 	private Integer round;
 

server/src/main/java/com/ticketing/server/movie/domain/Ticket.java

@@ -20,7 +20,7 @@ public class Ticket extends AbstractEntity {
 	@NotNull
 	@ManyToOne
 	@JoinColumn(name = "movie_times_id", referencedColumnName = "id", updatable = false)
-	private MovieTimes movieTimes;
+	private MovieTime movieTime;
 
 	@ManyToOne
 	@JoinColumn(name = "payment_id", referencedColumnName = "id", updatable = false)

server/src/main/java/com/ticketing/server/movie/domain/repository/MovieTimeRepository.java

@@ -0,0 +1,22 @@
+package com.ticketing.server.movie.domain.repository;
+
+import com.ticketing.server.movie.domain.Movie;
+import com.ticketing.server.movie.domain.MovieTime;
+import java.time.LocalDateTime;
+import java.util.List;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface MovieTimeRepository extends JpaRepository<MovieTime, Long> {
+
+    @Query(value = "SELECT mt "
+        + "FROM MovieTime mt "
+        + "JOIN FETCH mt.movie "
+        + "WHERE mt.movie = :movie "
+        + "AND mt.startAt "
+        + "BETWEEN :startOfDay AND :endOfDay", nativeQuery = false)
+    List<MovieTime> findValidMovieTimes(Movie movie, LocalDateTime startOfDay, LocalDateTime endOfDay);
+
+}

server/src/main/java/com/ticketing/server/movie/domain/repository/MovieTimesRepository.java

@@ -1,10 +0,0 @@
-package com.ticketing.server.movie.domain.repository;
-
-import com.ticketing.server.movie.domain.MovieTimes;
-import org.springframework.data.jpa.repository.JpaRepository;
-import org.springframework.stereotype.Repository;
-
-@Repository
-public interface MovieTimesRepository extends JpaRepository<MovieTimes, Long> {
-
-}

server/src/main/java/com/ticketing/server/movie/service/MovieServiceImpl.java

@@ -21,7 +21,7 @@ public class MovieServiceImpl implements MovieService {
         List<Movie> movies = movieRepository.findValidMovies();
 
         return movies.stream()
-            .map(movie -> movie.toDto())
+            .map(MovieDto::from)
             .collect(Collectors.toList());
 
     }

server/src/main/java/com/ticketing/server/movie/service/MovieTimeServiceImpl.java

@@ -0,0 +1,49 @@
+package com.ticketing.server.movie.service;
+
+import static com.ticketing.server.global.exception.ErrorCode.MOVIE_NOT_FOUND;
+
+import com.ticketing.server.global.exception.TicketingException;
+import com.ticketing.server.movie.domain.Movie;
+import com.ticketing.server.movie.domain.MovieTime;
+import com.ticketing.server.movie.domain.repository.MovieRepository;
+import com.ticketing.server.movie.domain.repository.MovieTimeRepository;
+import com.ticketing.server.movie.service.dto.MovieTimeDto;
+import com.ticketing.server.movie.service.interfaces.MovieTimeService;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.stream.Collectors;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class MovieTimeServiceImpl implements MovieTimeService {
+
+    private final MovieRepository movieRepository;
+
+    private final MovieTimeRepository movieTimeRepository;
+
+    @Override
+    public List<MovieTimeDto> getMovieTimes(String title, LocalDate runningDate) {
+        Movie movie = movieRepository.findByTitle(title)
+            .orElseThrow(MovieTimeServiceImpl::throwMovieNotFound);
+
+        LocalDateTime startOfDay = runningDate.atStartOfDay().plusHours(6);
+        LocalDateTime endOfDay = startOfDay.plusDays(1);
+
+        List<MovieTime> movieTimes = movieTimeRepository.findValidMovieTimes(movie, startOfDay, endOfDay);
+
+        return movieTimes.stream()
+            .map(MovieTimeDto::from)
+            .collect(Collectors.toList());
+
+    }
+
+    private static RuntimeException throwMovieNotFound() {
+        throw new TicketingException(MOVIE_NOT_FOUND);
+    }
+
+}

server/src/main/java/com/ticketing/server/movie/service/MovieTimesServiceImpl.java

@@ -1,9 +0,0 @@
-package com.ticketing.server.movie.service;
-
-import com.ticketing.server.movie.service.interfaces.MovieTimesService;
-import org.springframework.stereotype.Service;
-
-@Service
-public class MovieTimesServiceImpl implements MovieTimesService {
-
-}

server/src/main/java/com/ticketing/server/movie/service/TMBDServiceImpl.java

@@ -1,9 +0,0 @@
-package com.ticketing.server.movie.service;
-
-import com.ticketing.server.movie.service.interfaces.TMDBService;
-import org.springframework.stereotype.Service;
-
-@Service
-public class TMBDServiceImpl implements TMDBService {
-
-}

server/src/main/java/com/ticketing/server/movie/service/dto/MovieDto.java

@@ -1,12 +1,18 @@
 package com.ticketing.server.movie.service.dto;
 
-import com.fasterxml.jackson.annotation.JsonProperty;
+import com.ticketing.server.movie.domain.Movie;
+import lombok.AccessLevel;
 import lombok.AllArgsConstructor;
+import lombok.Getter;
 
-@AllArgsConstructor
+@Getter
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
 public class MovieDto {
 
-    @JsonProperty
     private String title;
 
+    public static MovieDto from(Movie movie) {
+        return new MovieDto(movie.getTitle());
+    }
+
 }

server/src/main/java/com/ticketing/server/movie/service/dto/MovieTimeDto.java

@@ -0,0 +1,28 @@
+package com.ticketing.server.movie.service.dto;
+
+import com.ticketing.server.movie.domain.MovieTime;
+import java.time.LocalDateTime;
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
+public class MovieTimeDto {
+
+    private long movieTimeId;
+
+    private Integer theaterNumber;
+
+    private Integer round;
+
+    private LocalDateTime startAt;
+
+    private LocalDateTime endAt;
+
+    public static MovieTimeDto from(MovieTime movieTime) {
+        return new MovieTimeDto(movieTime.getId(), movieTime.getTheater().getTheaterNumber(),
+            movieTime.getRound(), movieTime.getStartAt(), movieTime.getEndAt());
+    }
+
+}

server/src/main/java/com/ticketing/server/movie/service/interfaces/MovieTimeService.java

@@ -0,0 +1,11 @@
+package com.ticketing.server.movie.service.interfaces;
+
+import com.ticketing.server.movie.service.dto.MovieTimeDto;
+import java.time.LocalDate;
+import java.util.List;
+
+public interface MovieTimeService {
+
+    List<MovieTimeDto> getMovieTimes(String title, LocalDate runningDate);
+
+}

server/src/main/java/com/ticketing/server/movie/service/interfaces/MovieTimesService.java

@@ -1,5 +0,0 @@
-package com.ticketing.server.movie.service.interfaces;
-
-public interface MovieTimesService {
-
-}

server/src/main/java/com/ticketing/server/movie/service/interfaces/TMDBService.java

@@ -1,5 +0,0 @@
-package com.ticketing.server.movie.service.interfaces;
-
-public interface TMDBService {
-
-}

server/src/test/java/com/ticketing/server/movie/domain/repository/MovieTimeRepositoryTest.java

@@ -0,0 +1,18 @@
+package com.ticketing.server.movie.domain.repository;
+
+import javax.transaction.Transactional;
+import org.junit.jupiter.api.MethodOrderer;
+import org.junit.jupiter.api.TestMethodOrder;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+@Transactional
+@TestMethodOrder(MethodOrderer.OrderAnnotation.class)
+public class MovieTimeRepositoryTest {
+
+    @Autowired
+    MovieTimeRepository movieTimeRepository;
+
+
+}

server/src/test/java/com/ticketing/server/movie/domain/repository/MovieTimesRepositoryTest.java

@@ -1,5 +0,0 @@
-package com.ticketing.server.movie.domain.repository;
-
-public class MovieTimesRepositoryTest {
-
-}

server/src/test/java/com/ticketing/server/movie/service/MovieServiceImplTest.java

@@ -42,7 +42,6 @@ public class MovieServiceImplTest {
 
         // then
         assertTrue(movieDtoList.isEmpty());
-
     }
 
     @Test
@@ -50,7 +49,7 @@ public class MovieServiceImplTest {
     void shouldAbleToGetMovies() {
         // given
         movie = new Movie("범죄도시2", 106);
-        movieDto = movie.toDto();
+        movieDto = MovieDto.from(movie);
         movies.add(movie);
         movieDtos.add(movieDto);
 

server/src/test/java/com/ticketing/server/movie/service/MovieTimeServiceImplTest.java

@@ -0,0 +1,58 @@
+package com.ticketing.server.movie.service;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.Mockito.when;
+import static org.mockito.ArgumentMatchers.any;
+
+import com.ticketing.server.movie.domain.Movie;
+import com.ticketing.server.movie.domain.repository.MovieRepository;
+import com.ticketing.server.movie.domain.repository.MovieTimeRepository;
+import com.ticketing.server.movie.service.dto.MovieTimeDto;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.test.annotation.Rollback;
+
+@ExtendWith(MockitoExtension.class)
+public class MovieTimeServiceImplTest {
+
+    LocalDateTime startOfDay = LocalDate.now().atStartOfDay().plusHours(6);
+    LocalDateTime endOfDay = startOfDay.plusDays(1);
+
+    @Mock
+    MovieRepository movieRepository;
+
+    @Mock
+    MovieTimeRepository movieTimeRepository;
+
+    @InjectMocks
+    MovieTimeServiceImpl movieTimeService;
+
+    @Test
+    @DisplayName("MovieTime Service Test - get empty list when there is no valid movie times")
+    void shouldGetEmptyList() {
+        String title = "범죄도시2";
+        Movie movie = new Movie(title, 106);
+
+        when(movieRepository.findByTitle(title)).thenReturn(Optional.of(movie));
+        when(movieTimeRepository.findValidMovieTimes(any(), any(), any()))
+            .thenReturn(Collections.emptyList());
+
+        // when
+        List<MovieTimeDto> movieTimeDtoList = movieTimeService.getMovieTimes(title, LocalDate.now());
+
+        // then
+        assertTrue(movieTimeDtoList.isEmpty());
+
+    }
+
+}

server/src/test/java/com/ticketing/server/movie/service/TMDBServiceImplTest.java

@@ -1,94 +0,0 @@
-package com.ticketing.server.movie.service;
-
-import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
-import java.nio.charset.Charset;
-import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.Map;
-import org.junit.jupiter.api.DisplayName;
-import org.junit.jupiter.api.Test;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.beans.factory.annotation.Value;
-import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.http.HttpEntity;
-import org.springframework.http.HttpHeaders;
-import org.springframework.http.HttpMethod;
-import org.springframework.http.MediaType;
-import org.springframework.http.ResponseEntity;
-import org.springframework.web.client.RestTemplate;
-
-@SpringBootTest
-public class TMDBServiceImplTest {
-
-    @Value("${tmdb.api-key}")
-    private String apiKey;
-
-    @Value("${tmdb.read-access-token}")
-    private String readAccessToken;
-
-    @Autowired
-    RestTemplate restTemplate;
-
-    @Test
-    @DisplayName("TMDB Service Test - Get [Now Playing] movies")
-    void shouldAbleToGetMovieList() throws Exception {
-        // given
-        assertNotNull(apiKey);
-        assertNotNull(readAccessToken);
-
-        ArrayList<Charset> acceptCharset = new ArrayList<>();
-        acceptCharset.add(StandardCharsets.UTF_8);
-
-        HttpHeaders headers = new HttpHeaders();
-        headers.setAcceptCharset(acceptCharset);
-        headers.setContentType(MediaType.APPLICATION_JSON);
-        headers.setBearerAuth(readAccessToken);
-
-        Map<String, String> params = new HashMap<>();
-        params.put("api_key", apiKey);
-        params.put("language", "ko");
-
-        HttpEntity<?> request = new HttpEntity<>(headers);
-
-        // when
-        ResponseEntity<?> response = restTemplate.exchange(
-            "https://api.themoviedb.org/3/movie/now_playing?" + mapToUrlParam(params),
-            HttpMethod.GET,
-            request,
-            String.class
-        );
-
-//        JSONParser parser  = new JSONParser();
-//        Object obj = parser.parse(String.valueOf(response));
-//        Object results = ((JSONObject) obj).get("results");
-//
-//        ArrayList<String> movieList = new ArrayList<>();
-//
-//        ArrayList<JSONObject> jsonMovieList = new ArrayList<>();
-
-        // then
-        assertTrue(response.getStatusCode().is2xxSuccessful());
-    }
-
-    private static String mapToUrlParam(Map<String, String> params) {
-        StringBuffer paramData = new StringBuffer();
-
-        for (Map.Entry<String, String> param : params.entrySet()) {
-            if (paramData.length() != 0) {
-                paramData.append('&');
-            }
-
-            paramData.append(param.getKey());
-            paramData.append('=');
-            paramData.append(param.getValue());
-        }
-
-        return paramData.toString();
-    }
-
-}
-
-

server/src/test/resources/application.yml

@@ -31,7 +31,3 @@ jwt:
   secret-key: Zi1sYWItdGlja2V0aW5nLXByb2plY3Qtc3ByaW5nLWJvb3Qtc2VjdXJpdHktand0LXNlY3JldC1rZXktZi1sYWItdGlja2V0aW5nLXByb2plY3Qtc3ByaW5nLWJvb3Qtc2VjdXJpdHktand0LXNlY3JldC1rZXkK
   access-token-validity-in-seconds: 60
   refresh-token-validity-in-seconds: 259200
-
-tmdb:
-  api-key: 0d1503b6dcbfe1c514299b5564c649b8
-  read-access-token: eyJhbGciOiJIUzI1NiJ9.eyJhdWQiOiIwZDE1MDNiNmRjYmZlMWM1MTQyOTliNTU2NGM2NDliOCIsInN1YiI6IjYyOWYwODRlNzI2ZmIxMTA2NDA4MjI2NCIsInNjb3BlcyI6WyJhcGlfcmVhZCJdLCJ2ZXJzaW9uIjoxfQ.rs8KZea8QLyashILiggWFx2s46lgUtzo-xSWoDgE58A

test/.idea/.gitignore

@@ -0,0 +1,3 @@
+# Default ignored files
+/shelf/
+/workspace.xml

test/.idea/misc.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>

test/.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/test.iml" filepath="$PROJECT_DIR$/test.iml" />
+    </modules>
+  </component>
+</project>

test/.idea/runConfigurations.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="RunConfigurationProducerService">
+    <option name="ignoredProducers">
+      <set>
+        <option value="com.android.tools.idea.compose.preview.runconfiguration.ComposePreviewRunConfigurationProducer" />
+      </set>
+    </option>
+  </component>
+</project>

test/.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/.." vcs="Git" />
+  </component>
+</project>

test/src/SnowFlake.java

@@ -0,0 +1,148 @@
+public class SnowFlake {
+
+    //Data center (machine room) id
+    private long datacenterId;
+    //Machine ID
+    private long workerId;
+    //Same time series
+    private long sequence;
+
+    public SnowFlake(long workerId, long datacenterId) {
+        this(workerId, datacenterId, 0);
+    }
+
+    public SnowFlake(long workerId, long datacenterId, long sequence) {
+        //Legal judgment
+        if (workerId > maxWorkerId || workerId < 0) {
+            throw new IllegalArgumentException(String.format("worker Id can't be greater than %d or less than 0", maxWorkerId));
+        }
+        if (datacenterId > maxDatacenterId || datacenterId < 0) {
+            throw new IllegalArgumentException(String.format("datacenter Id can't be greater than %d or less than 0", maxDatacenterId));
+        }
+        System.out.printf("worker starting. timestamp left shift %d, datacenter id bits %d, worker id bits %d, sequence bits %d, workerid %d",
+            timestampLeftShift, datacenterIdBits, workerIdBits, sequenceBits, workerId);
+
+        this.workerId = workerId;
+        this.datacenterId = datacenterId;
+        this.sequence = sequence;
+    }
+
+    //Start timestamp
+    private long twepoch = 1420041600000L;
+
+    //Machine room number, the number of digits occupied by the ID of the machine room is 5 bits, the maximum is 11111 (binary) - > 31 (decimal)
+    private long datacenterIdBits = 5L;
+
+    //Machine ID所占的位数 5个bit 最大:11111(2进制)--> 31(10进制)
+    private long workerIdBits = 5L;
+
+    //5 bit can only have 31 digits at most, that is, the machine ID can only be within 32 at most
+    private long maxWorkerId = -1L ^ (-1L << workerIdBits);
+
+    //5-bit can only have 31 digits at most, and the machine room ID can only be within 32 at most
+    private long maxDatacenterId = -1L ^ (-1L << datacenterIdBits);
+
+    //Same time series所占的位数 12个bit 111111111111 = 4095  最多就是同一毫秒生成4096个
+    private long sequenceBits = 12L;
+
+    //Offset of workerid
+    private long workerIdShift = sequenceBits;
+
+    //Offset of datacenter ID
+    private long datacenterIdShift = sequenceBits + workerIdBits;
+
+    //Offset of timestampleft
+    private long timestampLeftShift = sequenceBits + workerIdBits + datacenterIdBits;
+
+    //Serial number mask 4095 (0b111111 = 0xfff = 4095)
+    //It is used for the sum operation of serial number to ensure that the maximum value of serial number is between 0-4095
+    private long sequenceMask = -1L ^ (-1L << sequenceBits);
+
+    //Last timestamp
+    private long lastTimestamp = -1L;
+
+
+    //Get machine ID
+    public long getWorkerId() {
+        return workerId;
+    }
+
+
+    //Get machine room ID
+    public long getDatacenterId() {
+        return datacenterId;
+    }
+
+
+    //Get the latest timestamp
+    public long getLastTimestamp() {
+        return lastTimestamp;
+    }
+
+
+    //Get the next random ID
+    public synchronized long nextId() {
+        //Gets the current timestamp in milliseconds
+        long timestamp = timeGen();
+
+        if (timestamp < lastTimestamp) {
+            System.err.printf("clock is moving backwards.  Rejecting requests until %d.", lastTimestamp);
+            throw new RuntimeException(String.format("Clock moved backwards.  Refusing to generate id for %d milliseconds",
+                lastTimestamp - timestamp));
+        }
+
+        //Weight removal
+        if (lastTimestamp == timestamp) {
+
+            sequence = (sequence + 1) & sequenceMask;
+
+            //Sequence sequence is greater than 4095
+            if (sequence == 0) {
+                //Method called to the next timestamp
+                timestamp = tilNextMillis(lastTimestamp);
+            }
+        } else {
+            //If it is the first acquisition of the current time, it is set to 0
+            sequence = 0;
+        }
+
+        //Record the last timestamp
+        lastTimestamp = timestamp;
+
+        //Offset calculation
+        return ((timestamp - twepoch) << timestampLeftShift) |
+            (datacenterId << datacenterIdShift) |
+            (workerId << workerIdShift) |
+            sequence;
+    }
+
+    private long tilNextMillis(long lastTimestamp) {
+        //Get latest timestamp
+        long timestamp = timeGen();
+        //If the latest timestamp is found to be less than or equal to the timestamp whose serial number has exceeded 4095
+        while (timestamp <= lastTimestamp) {
+            //If not, continue
+            timestamp = timeGen();
+        }
+        return timestamp;
+    }
+
+    private long timeGen() {
+        return System.currentTimeMillis();
+    }
+
+    public static void main(String[] args) {
+        SnowFlake worker = new SnowFlake(1, 1);
+        long timer = System.currentTimeMillis();
+        for (int i = 0; i < 100; i++) {
+            worker.nextId();
+        }
+        System.out.println(System.currentTimeMillis());
+        System.out.println(System.currentTimeMillis() - timer);
+        for(int i=0; i<200; i++) {
+            System.out.println( );
+            System.out.println(worker.nextId());
+        }
+    }
+
+}

test/test.iml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>