저는 Customer 클래스를 선언할 때 name, age를 private 으로 선언하고 Getter, Setter를 이용하여 값을 접근할려고 짯습니다. 근데 map() 을 하는 과정에서 아래와 같은 오류가 떠서 setName()을 그냥 String 반환값으로 고쳐서 했더니 에러가 해결이 됐습니다. 근데 왜 이런 오류가 났는지 이해가 안갑니다  public class _Quiz_10 { public static void main(String[] args) { List<Customer> customerList = new ArrayList<>(); customerList.add(new Customer("챈들러",50)); customerList.add(new Customer("레이첼", 42)); customerList.add(new Customer("모니카", 21)); customerList.add(new Customer("벤자민", 18)); customerList.add(new Customer("제임스", 5)); System.out.println("미술관 입장료"); System.out.println("=================="); customerList.stream() .map(x->x.getAge()>=20 ? x.setName(x.getName() + " 5000원"):x.setName(x.getName()+ " 무료")) .forEach(System.out::println); } } class Customer{ private String name; private int age; public Customer(String name, int age) { this.name = name; this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } }

먼저 강의 잘 들었습니다.취준 중인데도 이해가 잘 돼서 좋습니다! 다름이 아니라 동시성 제어를 할 때 redis, kafka로도 해결할 수 있다는 것은 알겠습니다. 다만, Lock으로도 동시성 제어도 할 수 있지만 줄줄이 기다리기 때문에 선착순 쿠폰 같은 이슈에 대해서는 비관적 락을 걸 경우 100명까지 순차적으로 느리게 된다는 것으로 이해했는데 맞을까요? 제가 이해한 것이 맞다면 락을 사용하면 많이 느릴텐데 보통 어떤 경우에 락을 통해 동시성 제어를 하고, 어떤 경우에 카프카를 쓰시나요? 같은 경우라도 상황마다 다르겠지만.. 예시를 조금만 들어주실 수 있을까요? 잘 이해를 하지 못해서 질문 남깁니다감사합니다

 package chap_11; public class _Quiz_11 { public static void main(String[] args) { //todo 사용자 정의 예외 클래스(extends Exception을 통해 가능) //todo 예외 객체 생성 메시지가 2개인 것을 보아, 클래스도 2개를 만들어야 할듯...? //todo 경우의 수가 3가지니까 if~else문으로 작성 int errorCode = 0; try { switch (errorCode) { case 0: System.out.println("상품 구매를 완료하였습니다."); break; case 1: throw new NotOnSaleException("상품 구매 가능 시간이 아닙니다."); case 2: throw new SoldOutException("해당 상품은 매진되었습니다."); default: throw new Exception("이외의 에러코드는 여기서 처리하였습니다."); } } catch (NotOnSaleException e) { System.out.println(e.getMessage()); System.out.println("상품 구매는 20시부터 가능합니다."); } catch (SoldOutException e) { System.out.println(e.getMessage()); System.out.println("다음 기회에 이용해주세요."); } catch (Exception e) { System.out.println(e.getMessage()); } } } class NotOnSaleException extends Exception { public NotOnSaleException(String msg) { super(msg); } } class SoldOutException extends Exception { public SoldOutException(String msg) { super(msg); } }위의 errorCode를 각각넣으면 퀴즈의 요구사항대로 정상적으로 출력이 됩니다. 또한, int errorCode = 99; 같이 default에 해당하는 다른 값을 넣어도 정상적으로 다음과 같이 출력이 되구요:제목과 같이 if~else문이나 swtich문으로 선택하는 것은 개인의 자유인가요? 아니면 특정 상황에 따라 다른가요?

저번 수업도 그렇고...반복문 작성할 때 아 이거는 i<N인가? M인가? 이게 햇갈리는데, 뭐 좋은 방법 없을까요?

학습하는 분들께 도움이 되고, 더 좋은 답변을 드릴 수 있도록 질문전에 다음을 꼭 확인해주세요.1. 강의 내용과 관련된 질문을 남겨주세요.2. 인프런의 질문 게시판과 자주 하는 질문(링크)을 먼저 확인해주세요.(자주 하는 질문 링크: https://bit.ly/3fX6ygx)3. 질문 잘하기 메뉴얼(링크)을 먼저 읽어주세요.(질문 잘하기 메뉴얼 링크: https://bit.ly/2UfeqCG)질문 시에는 위 내용은 삭제하고 다음 내용을 남겨주세요.=========================================[질문 템플릿]1. 강의 내용과 관련된 질문인가요? (예/아니오)2. 인프런의 질문 게시판과 자주 하는 질문에 없는 내용인가요? (예/아니오)3. 질문 잘하기 메뉴얼을 읽어보셨나요? (예/아니오)[질문 내용]여기에 질문 내용을 남겨주세요. 안녕하세요! h2접속하면 저렇게 member 테이블만 뜨고 생성이 안되어있습니다..ㅠ

학습하는 분들께 도움이 되고, 더 좋은 답변을 드릴 수 있도록 질문전에 다음을 꼭 확인해주세요.1. 강의 내용과 관련된 질문을 남겨주세요.2. 인프런의 질문 게시판과 자주 하는 질문(링크)을 먼저 확인해주세요.(자주 하는 질문 링크: https://bit.ly/3fX6ygx)3. 질문 잘하기 메뉴얼(링크)을 먼저 읽어주세요.(질문 잘하기 메뉴얼 링크: https://bit.ly/2UfeqCG)질문 시에는 위 내용은 삭제하고 다음 내용을 남겨주세요.=========================================[질문 템플릿]1. 강의 내용과 관련된 질문인가요? (예/아니오)2. 인프런의 질문 게시판과 자주 하는 질문에 없는 내용인가요? (예/아니오)3. 질문 잘하기 메뉴얼을 읽어보셨나요? (예/아니오)[질문 내용]"C:\Program Files\Java\jdk-11\bin\java.exe" "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2022.3.3\lib\idea_rt.jar=50808:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2022.3.3\bin" -Dfile.encoding=UTF-8 -classpath "C:\Users\민규\OneDrive\바탕 화면\Study\jpashop\out\production\classes;C:\Users\민규\OneDrive\바탕 화면\Study\jpashop\out\production\resources;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-data-jpa\2.7.14\ad7d3be24a386ec45ce020b8922e9d056f7a6835\spring-boot-starter-data-jpa-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-validation\2.7.14\6e88ca463b6d7294f3206da9a57a645ca41b9665\spring-boot-starter-validation-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-thymeleaf\2.7.14\91a1934c6fae08a28665182ab802d41e0b44ffd\spring-boot-starter-thymeleaf-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-web\2.7.14\300b311c5fb98a2ee547df33a9d37782dddb496e\spring-boot-starter-web-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-aop\2.7.14\c4fb902f51ab09247de60c463761980d0d1a5888\spring-boot-starter-aop-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-jdbc\2.7.14\80b80408b6b75ce0dc2833cb07fd1ce6620d1f3b\spring-boot-starter-jdbc-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\jakarta.transaction\jakarta.transaction-api\1.3.3\c4179d48720a1e87202115fbed6089bdc4195405\jakarta.transaction-api-1.3.3.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\jakarta.persistence\jakarta.persistence-api\2.2.3\8f6ea5daedc614f07a3654a455660145286f024e\jakarta.persistence-api-2.2.3.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.hibernate\hibernate-core\5.6.15.Final\ab14b7cef1fdff654ca81923048a6034d6c7cfa7\hibernate-core-5.6.15.Final.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.data\spring-data-jpa\2.7.14\d5f2e34cce48ed4d668e760db200e854cbbe4d87\spring-data-jpa-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-aspects\5.3.29\dbcf1c1ce847b0fb186b5dde18968c9a46900f28\spring-aspects-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter\2.7.14\5506200907ff3c3458506a8e16866c684f28bdbd\spring-boot-starter-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.apache.tomcat.embed\tomcat-embed-el\9.0.78\a39a2f2839516a5d3c05a4c0d7d1252a114a5b91\tomcat-embed-el-9.0.78.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.hibernate.validator\hibernate-validator\6.2.5.Final\a68959c06e5f8ff45faff469aa16f232c04af620\hibernate-validator-6.2.5.Final.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.thymeleaf\thymeleaf-spring5\3.0.15.RELEASE\7170e1bcd1588d38c139f7048ebcc262676441c3\thymeleaf-spring5-3.0.15.RELEASE.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.thymeleaf.extras\thymeleaf-extras-java8time\3.0.4.RELEASE\36e7175ddce36c486fff4578b5af7bb32f54f5df\thymeleaf-extras-java8time-3.0.4.RELEASE.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-json\2.7.14\34fbe387993dafef8b2c29516ebe54fec7108181\spring-boot-starter-json-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-tomcat\2.7.14\e203b8792f4bcfaa1d07956adb6dee7014a20881\spring-boot-starter-tomcat-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-webmvc\5.3.29\fdaefee29fcb8459aab748b571d8bb7bb7fdb175\spring-webmvc-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-web\5.3.29\4cd333e48d9a05d05c05ae7426242ecfe4cfb681\spring-web-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-aop\5.3.29\397c588ce63ba4c185a8c1bd2f1e9139075b3bf1\spring-aop-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.aspectj\aspectjweaver\1.9.7\158f5c255cd3e4408e795b79f7c3fbae9b53b7ca\aspectjweaver-1.9.7.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\com.zaxxer\HikariCP\4.0.3\107cbdf0db6780a065f895ae9d8fbf3bb0e1c21f\HikariCP-4.0.3.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-jdbc\5.3.29\25c0b36f780af98b2d3b554e9a6258ac599b6115\spring-jdbc-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.hibernate.common\hibernate-commons-annotations\5.1.2.Final\e59ffdbc6ad09eeb33507b39ffcf287679a498c8\hibernate-commons-annotations-5.1.2.Final.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.jboss.logging\jboss-logging\3.4.3.Final\c4bd7e12a745c0e7f6cf98c45cdcdf482fd827ea\jboss-logging-3.4.3.Final.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\net.bytebuddy\byte-buddy\1.12.23\d470526e8c4566c04e9ae5d3ccb62d1a7aa58986\byte-buddy-1.12.23.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\antlr\antlr\2.7.7\83cd2cd674a217ade95a4bb83a8a14f351f48bd0\antlr-2.7.7.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.jboss\jandex\2.4.2.Final\1e1c385990b258ff1a24c801e84aebbacf70eb39\jandex-2.4.2.Final.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\com.fasterxml\classmate\1.5.1\3fe0bed568c62df5e89f4f174c101eab25345b6c\classmate-1.5.1.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.glassfish.jaxb\jaxb-runtime\2.3.8\c90a335a07c60db986f29d35b0f8ac0a18f0f989\jaxb-runtime-2.3.8.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-context\5.3.29\c374a72716d19220ca142efaab910adf5717c5d0\spring-context-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-orm\5.3.29\83953e2af9c1848227239b4695c7596a0f112da3\spring-orm-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.data\spring-data-commons\2.7.14\c8c4825d930c9615bc7c9b42f433c9c14761fcaa\spring-data-commons-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-tx\5.3.29\dd26c6e31db036c3f96c24e8ff3b769a00dfc999\spring-tx-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-beans\5.3.29\be40f557f3fa52c703f00e127ff639f8cf499617\spring-beans-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-core\5.3.29\528eafe4cef7bccf3df290dd99ac5833a9756183\spring-core-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.slf4j\slf4j-api\1.7.36\6c62681a2f655b49963a5983b8b0950a6120ae14\slf4j-api-1.7.36.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-autoconfigure\2.7.14\4851957607f74fc4335858d66fb755f1b0c95006\spring-boot-autoconfigure-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot\2.7.14\762261093a3e15388216c45d6a9ba7fdc022b74d\spring-boot-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-logging\2.7.14\ea9c060fd1e4d17cdd8a9ba3dec8076c17d22a23\spring-boot-starter-logging-2.7.14.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\jakarta.annotation\jakarta.annotation-api\1.3.5\59eb84ee0d616332ff44aba065f3888cf002cd2d\jakarta.annotation-api-1.3.5.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.yaml\snakeyaml\1.30\8fde7fe2586328ac3c68db92045e1c8759125000\snakeyaml-1.30.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\jakarta.validation\jakarta.validation-api\2.0.2\5eacc6522521f7eacb081f95cee1e231648461e7\jakarta.validation-api-2.0.2.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.thymeleaf\thymeleaf\3.0.15.RELEASE\13e3296a03d8a597b734d832ed8656139bf9cdd8\thymeleaf-3.0.15.RELEASE.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.datatype\jackson-datatype-jsr310\2.13.5\8ba3b868e81d7fc6ead686bd2353859b111d9eaf\jackson-datatype-jsr310-2.13.5.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.module\jackson-module-parameter-names\2.13.5\a401a99e7a45450fd3ef76e82ba39005fd1a8c22\jackson-module-parameter-names-2.13.5.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.datatype\jackson-datatype-jdk8\2.13.5\1278f38160812811c56eb77f67213662ed1c7a2e\jackson-datatype-jdk8-2.13.5.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.core\jackson-databind\2.13.5\aa95e46dbc32454f3983221d420e78ef19ddf844\jackson-databind-2.13.5.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.apache.tomcat.embed\tomcat-embed-websocket\9.0.78\3d389e849edf92d5bc6a778a47428581773af3d6\tomcat-embed-websocket-9.0.78.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.apache.tomcat.embed\tomcat-embed-core\9.0.78\ff73a2003d4b066b9affdc70827f6e8d282ab723\tomcat-embed-core-9.0.78.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-expression\5.3.29\44ac795a057c4a6360063801c54a2d148e5a2808\spring-expression-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\jakarta.xml.bind\jakarta.xml.bind-api\2.3.3\48e3b9cfc10752fba3521d6511f4165bea951801\jakarta.xml.bind-api-2.3.3.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.glassfish.jaxb\txw2\2.3.8\66e0297f1196f0d15a776e699de1b8e6ac5d44dd\txw2-2.3.8.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\com.sun.istack\istack-commons-runtime\3.0.12\cbbe1a62b0cc6c85972e99d52aaee350153dc530\istack-commons-runtime-3.0.12.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.springframework\spring-jcl\5.3.29\4f84fbeec60adb1a50734b6077836e53844f0134\spring-jcl-5.3.29.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\ch.qos.logback\logback-classic\1.2.12\d4dee19148dccb177a0736eb2027bd195341da78\logback-classic-1.2.12.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.apache.logging.log4j\log4j-to-slf4j\2.17.2\17dd0fae2747d9a28c67bc9534108823d2376b46\log4j-to-slf4j-2.17.2.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.slf4j\jul-to-slf4j\1.7.36\ed46d81cef9c412a88caef405b58f93a678ff2ca\jul-to-slf4j-1.7.36.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.attoparser\attoparser\2.0.5.RELEASE\a93ad36df9560de3a5312c1d14f69d938099fa64\attoparser-2.0.5.RELEASE.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.unbescape\unbescape\1.1.6.RELEASE\7b90360afb2b860e09e8347112800d12c12b2a13\unbescape-1.1.6.RELEASE.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.core\jackson-annotations\2.13.5\136f77ab424f302c9e27230b4482e8000e142edf\jackson-annotations-2.13.5.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.core\jackson-core\2.13.5\d07c97d3de9ea658caf1ff1809fd9de930a286a\jackson-core-2.13.5.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\ch.qos.logback\logback-core\1.2.12\1d8e51a698b138065d73baefb4f94531faa323cb\logback-core-1.2.12.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\org.apache.logging.log4j\log4j-api\2.17.2\f42d6afa111b4dec5d2aea0fe2197240749a4ea6\log4j-api-2.17.2.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\com.h2database\h2\2.1.214\d5c2005c9e3279201e12d4776c948578b16bf8b2\h2-2.1.214.jar;C:\Users\민규\.gradle\caches\modules-2\files-2.1\com.sun.activation\jakarta.activation\1.2.2\74548703f9851017ce2f556066659438019e7eb5\jakarta.activation-1.2.2.jar" jpabook.jpashop.JpashopApplication. ____ _/\\ / ___'_ __ (_)_ _ \ \ \ \( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \\\/ ___)| |_)| | | | | || (_| | ) ) ) )' |____| .__|_| |_|_| |_\__, | / / / /=========|_|==============|___/=/_/_/_/:: Spring Boot :: (v2.7.14)2023-08-16 15:16:35.129 INFO 6060 --- [ main] jpabook.jpashop.JpashopApplication : Starting JpashopApplication using Java 11.0.18 on DESKTOP-R06VPME with PID 6060 (C:\Users\민규\OneDrive\바탕 화면\Study\jpashop\out\production\classes started by 민규 in C:\Users\민규\OneDrive\바탕 화면\Study\jpashop)2023-08-16 15:16:35.136 INFO 6060 --- [ main] jpabook.jpashop.JpashopApplication : No active profile set, falling back to 1 default profile: "default"2023-08-16 15:16:36.872 INFO 6060 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data JPA repositories in DEFAULT mode.2023-08-16 15:16:36.903 INFO 6060 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 14 ms. Found 0 JPA repository interfaces.2023-08-16 15:16:38.080 INFO 6060 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)2023-08-16 15:16:38.094 INFO 6060 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]2023-08-16 15:16:38.094 INFO 6060 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.78]2023-08-16 15:16:38.273 INFO 6060 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext2023-08-16 15:16:38.273 INFO 6060 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 2995 ms2023-08-16 15:16:38.545 INFO 6060 --- [ main] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [name: default]2023-08-16 15:16:38.624 INFO 6060 --- [ main] org.hibernate.Version : HHH000412: Hibernate ORM core version 5.6.15.Final2023-08-16 15:16:38.916 INFO 6060 --- [ main] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.1.2.Final}2023-08-16 15:16:39.035 INFO 6060 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...2023-08-16 15:16:39.190 INFO 6060 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.2023-08-16 15:16:39.228 INFO 6060 --- [ main] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.H2Dialect2023-08-16 15:16:39.542 ERROR 6060 --- [ main] j.LocalContainerEntityManagerFactoryBean : Failed to initialize JPA EntityManagerFactory: Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements: jpabook.jpashop.domain.Order.member2023-08-16 15:16:39.543 WARN 6060 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements: jpabook.jpashop.domain.Order.member2023-08-16 15:16:39.543 INFO 6060 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown initiated...2023-08-16 15:16:39.560 INFO 6060 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown completed.2023-08-16 15:16:39.565 INFO 6060 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat]2023-08-16 15:16:39.582 INFO 6060 --- [ main] ConditionEvaluationReportLoggingListener :Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.2023-08-16 15:16:39.615 ERROR 6060 --- [ main] o.s.boot.SpringApplication : Application run failedorg.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements: jpabook.jpashop.domain.Order.memberat org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1804) ~[spring-beans-5.3.29.jar:5.3.29]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:620) ~[spring-beans-5.3.29.jar:5.3.29]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.29.jar:5.3.29]at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.29.jar:5.3.29]at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.29.jar:5.3.29]at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.29.jar:5.3.29]at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.29.jar:5.3.29]at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1157) ~[spring-context-5.3.29.jar:5.3.29]at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:911) ~[spring-context-5.3.29.jar:5.3.29]at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.29.jar:5.3.29]at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:147) ~[spring-boot-2.7.14.jar:2.7.14]at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:731) ~[spring-boot-2.7.14.jar:2.7.14]at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:408) ~[spring-boot-2.7.14.jar:2.7.14]at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) ~[spring-boot-2.7.14.jar:2.7.14]at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303) ~[spring-boot-2.7.14.jar:2.7.14]at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292) ~[spring-boot-2.7.14.jar:2.7.14]at jpabook.jpashop.JpashopApplication.main(JpashopApplication.java:11) ~[classes/:na]Caused by: org.hibernate.AnnotationException: Illegal attempt to map a non collection as a @OneToMany, @ManyToMany or @CollectionOfElements: jpabook.jpashop.domain.Order.memberat org.hibernate.cfg.annotations.CollectionBinder.getCollectionBinder(CollectionBinder.java:325) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]at org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:1977) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]at org.hibernate.cfg.AnnotationBinder.processIdPropertiesIfNotAlready(AnnotationBinder.java:968) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:793) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.processEntityHierarchies(AnnotationMetadataSourceProcessorImpl.java:225) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]at org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.processEntityHierarchies(MetadataBuildingProcess.java:239) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:282) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1460) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1494) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final]at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.3.29.jar:5.3.29]at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.3.29.jar:5.3.29]at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-5.3.29.jar:5.3.29]at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-5.3.29.jar:5.3.29]at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.3.29.jar:5.3.29]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) ~[spring-beans-5.3.29.jar:5.3.29]at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) ~[spring-beans-5.3.29.jar:5.3.29]... 16 common frames omittedProcess finished with exit code 1main메소드실행하면 이렇게 뜨고 종료 됩니다 h2 서버에 테이블도 안 만들어져요http://naver.me/x6ABJK1o <- domain 파일 주소

도서관 애플리케이션을 실행하는 도중 아래와 같은 긴 오류가 떴습니다. 검색을 해도 잘 모르겠습니다 ㅠ어떻게 해야 할까요? Error executing DDL "drop table if exists user cascade " via JDBC StatementCaused by: org.h2.jdbc.JdbcSQLSyntaxErrorException: Syntax error in SQL statement "drop table if exists [*]user cascade "; expected "identifier"; SQL statement:Error executing DDL "create table user (id bigint generated by default as identity, age integer, name varchar(20) not null, primary key (id))" via JDBC StatementCaused by: org.h2.jdbc.JdbcSQLSyntaxErrorException: Syntax error in SQL statement "create table [*]user (id bigint generated by default as identity, age integer, name varchar(20) not null, primary key (id))"; expected "identifier"; SQL statement:Error executing DDL "alter table if exists user_loan_history add constraint FKa17jbf1po26eytdyvyj73b4rw foreign key (user_id) references user" via JDBC StatementCaused by: org.h2.jdbc.JdbcSQLSyntaxErrorException: Syntax error in SQL statement "alter table if exists user_loan_history add constraint FKa17jbf1po26eytdyvyj73b4rw foreign key (user_id) references [*]user"; expected "identifier"; SQL statement: 

구글링해보니 자바8이상이면 메서드 쓸 수 있다는데 저는 자바 11버전이거든요 왜 이럴까요ㅠㅠ

안녕하세요실무에서 db 스키마를 수정할때리퀴베이스를 사용하고 있습니다 그래서ddl-auto 를 이용하거나디비에서 직접 수정하는 방법은이력관리가 되지 않아서 지양하고관리 포인트를 리퀴베이스로만 하려고 하는데요어떤 방법은 좋은지 고민이 되네요 김영한님은 실무에서 어떤 기술로디비 스키마를 관리 하시는지 궁금합니다

학습하는 분들께 도움이 되고, 더 좋은 답변을 드릴 수 있도록 질문전에 다음을 꼭 확인해주세요.1. 강의 내용과 관련된 질문을 남겨주세요.2. 인프런의 질문 게시판과 자주 하는 질문(링크)을 먼저 확인해주세요.(자주 하는 질문 링크: https://bit.ly/3fX6ygx)3. 질문 잘하기 메뉴얼(링크)을 먼저 읽어주세요.(질문 잘하기 메뉴얼 링크: https://bit.ly/2UfeqCG)질문 시에는 위 내용은 삭제하고 다음 내용을 남겨주세요.=========================================[질문 템플릿]1. 강의 내용과 관련된 질문인가요? (예/아니오)2. 인프런의 질문 게시판과 자주 하는 질문에 없는 내용인가요? (예/아니오)3. 질문 잘하기 메뉴얼을 읽어보셨나요? (예/아니오)[질문 내용]안녕하세요. 강의 정말 잘 듣고있습니다! 대량의 데이터가 있는 상황에서 count 쿼리를 page가 바뀔 때 마다 날리는 것은 부담이 되는 것 같습니다.index를 적용하면 좋겠지만 전체 데이터에 대한 pagenation이라고 하면 index를 적용하기도 어려움이 있을 것 같습니다. 이런 경우에는 매일 특정 시간에 count 쿼리를 날려서 전체 개수를 캐시에 저장해두고 변경이 일어날 때마다 추가/삭제된 데이터의 개수를 +/- 해서 total count의 개수를 오차 없이 유지하는 방법을 생각 할 수 있을 것 같은데 제가 생각한 방식으로 캐시를 사용해도 괜찮을까요?

혹시 구현문제의 대한 강의는 올라오지 않을까요?다음 예정된 강의는 어떤 종류의 알고리즘인지 궁금합니다.

fetchtype을 LAZY로 설정했을 경우 N+1문제는 이해했습니다. 그런데 EAGER의 경우 Order를 위한 1개의 select쿼리 뒤에 delivery를 위한 1개의 쿼리와 3중 조인문 2개의 쿼리가 나가고 있는데 (위 사진) join문이 EAGER처리를 위한 쿼리라면 왜 order 조회쿼리 뒤에 바로 나가지 않고 delivery 조회쿼리가 한번 나간 뒤에 나가는건지 왜 delivery에 대한 추가 쿼리는 나가는데 member는 조회쿼리가 나가지 않고 join문이 나가는지 EAGER의 경우에도 모든 연관객체가 영속성 콘텍스트 안에 존재하지 않는다면 정확히 1+N개의 쿼리가 나가는지 (=LAZY와 똑같이 1+N개의 쿼리가 나가는지) 이 세가지가 이해되지 않습니다.EAGER일때 쿼리를 이해해보려고 노력했는데 "LAZY와는 추가쿼리(N)가 나가는 시점의 차이가 있다" 정도 말고는 이해가 되지 않아 질문드립니다.

No matching variant of org.springframework.boot:spring-boot-gradle-plugin:3.1.2 was found. The consumer was configured to find a library for use during runtime, compatible with Java 11, packaged as a jar, and its dependencies declared externally, as well as attribute 'org.gradle.plugin.api-version' with value '8.2.1' but: 현재 SDK는 11 Oracle, Language level은 11- local variable syntax for lambda parameters로 되어있습니다. 원래는 컴파일이 됐었는데 1번 강의(스프링 프로젝트를 시작하는 두 번째 방법) 이후 안되는 것 같습니다. 어떻게 해야할까요?

학습하는 분들께 도움이 되고, 더 좋은 답변을 드릴 수 있도록 질문전에 다음을 꼭 확인해주세요.1. 강의 내용과 관련된 질문을 남겨주세요.2. 인프런의 질문 게시판과 자주 하는 질문(링크)을 먼저 확인해주세요.(자주 하는 질문 링크: https://bit.ly/3fX6ygx)3. 질문 잘하기 메뉴얼(링크)을 먼저 읽어주세요.(질문 잘하기 메뉴얼 링크: https://bit.ly/2UfeqCG)질문 시에는 위 내용은 삭제하고 다음 내용을 남겨주세요.=========================================[질문 템플릿]1. 강의 내용과 관련된 질문인가요? (예/아니오)2. 인프런의 질문 게시판과 자주 하는 질문에 없는 내용인가요? (예/아니오)3. 질문 잘하기 메뉴얼을 읽어보셨나요? (예/아니오)[질문 내용]여기에 질문 내용을 남겨주세요.QueryDlsApplicationTest.java를 실행하면,org.hibernate.exception.SQLGrammarException: could not prepare statement [Sequence "HELLO_SEQ" not found; SQL statement:select next value for hello_seq [90036-214]] [select next value for hello_seq]at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:64)at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:56)at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:108)at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:187)at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareStatement(StatementPreparerImpl.java:76)at org.hibernate.id.enhanced.SequenceStructure$1.getNextValue(SequenceStructure.java:100)at org.hibernate.id.enhanced.PooledOptimizer.generate(PooledOptimizer.java:72)at org.hibernate.id.enhanced.SequenceStyleGenerator.generate(SequenceStyleGenerator.java:542)at org.hibernate.id.IdentifierGenerator.generate(IdentifierGenerator.java:147)at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:120)at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:175)at org.hibernate.event.internal.DefaultPersistEventListener.persist(DefaultPersistEventListener.java:93)at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:77)at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:54)at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:127)at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:755)at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:739)at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.base/java.lang.reflect.Method.invoke(Method.java:568)at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:311)at jdk.proxy2/jdk.proxy2.$Proxy108.persist(Unknown Source)at study.querydsl.QuerydslApplicationTests.contextLoads(QuerydslApplicationTests.java:25)at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.base/java.lang.reflect.Method.invoke(Method.java:568)at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:727)at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:156)at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:147)at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:86)at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(InterceptingExecutableInvoker.java:103)at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.lambda$invoke$0(InterceptingExecutableInvoker.java:93)at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.invoke(InterceptingExecutableInvoker.java:92)at org.junit.jupiter.engine.execution.InterceptingExecutableInvoker.invoke(InterceptingExecutableInvoker.java:86)at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$7(TestMethodTestDescriptor.java:217)at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:213)at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:138)at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:68)at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:151)at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:147)at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:127)at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:90)at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:55)at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:102)at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:54)at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114)at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86)at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86)at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53)at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:57)at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:232)at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:55)Caused by: org.h2.jdbc.JdbcSQLSyntaxErrorException: Sequence "HELLO_SEQ" not found; SQL statement:select next value for hello_seq [90036-214]at org.h2.message.DbException.getJdbcSQLException(DbException.java:632)at org.h2.message.DbException.getJdbcSQLException(DbException.java:477)at org.h2.message.DbException.get(DbException.java:223)at org.h2.message.DbException.get(DbException.java:199)at org.h2.command.Parser.readSequence(Parser.java:8471)at org.h2.command.Parser.readTermWithIdentifier(Parser.java:5347)at org.h2.command.Parser.readTermWithIdentifier(Parser.java:5217)at org.h2.command.Parser.readTerm(Parser.java:4901)at org.h2.command.Parser.readFactor(Parser.java:3398)at org.h2.command.Parser.readSum(Parser.java:3385)at org.h2.command.Parser.readConcat(Parser.java:3350)at org.h2.command.Parser.readCondition(Parser.java:3132)at org.h2.command.Parser.readExpression(Parser.java:3053)at org.h2.command.Parser.parseSelectExpressions(Parser.java:2853)at org.h2.command.Parser.parseSelect(Parser.java:2871)at org.h2.command.Parser.parseQueryPrimary(Parser.java:2762)at org.h2.command.Parser.parseQueryTerm(Parser.java:2633)at org.h2.command.Parser.parseQueryExpressionBody(Parser.java:2612)at org.h2.command.Parser.parseQueryExpressionBodyAndEndOfQuery(Parser.java:2605)at org.h2.command.Parser.parseQueryExpression(Parser.java:2598)at org.h2.command.Parser.parseQuery(Parser.java:2567)at org.h2.command.Parser.parsePrepared(Parser.java:724)at org.h2.command.Parser.parse(Parser.java:689)at org.h2.command.Parser.parse(Parser.java:661)at org.h2.command.Parser.prepareCommand(Parser.java:569)at org.h2.engine.SessionLocal.prepareLocal(SessionLocal.java:631)at org.h2.server.TcpServerThread.process(TcpServerThread.java:288)at org.h2.server.TcpServerThread.run(TcpServerThread.java:191)at java.base/java.lang.Thread.run(Thread.java:834)at org.h2.message.DbException.getJdbcSQLException(DbException.java:632)at org.h2.engine.SessionRemote.readException(SessionRemote.java:637)at org.h2.engine.SessionRemote.done(SessionRemote.java:606)at org.h2.command.CommandRemote.prepare(CommandRemote.java:78)at org.h2.command.CommandRemote.<init>(CommandRemote.java:50)at org.h2.engine.SessionRemote.prepareCommand(SessionRemote.java:480)at org.h2.jdbc.JdbcConnection.prepareCommand(JdbcConnection.java:1116)at org.h2.jdbc.JdbcPreparedStatement.<init>(JdbcPreparedStatement.java:92)at org.h2.jdbc.JdbcConnection.prepareStatement(JdbcConnection.java:288)at com.zaxxer.hikari.pool.ProxyConnection.prepareStatement(ProxyConnection.java:327)at com.zaxxer.hikari.pool.HikariProxyConnection.prepareStatement(HikariProxyConnection.java)at com.p6spy.engine.wrapper.ConnectionWrapper.prepareStatement(ConnectionWrapper.java:118)at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$1.doPrepare(StatementPreparerImpl.java:91)at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:177)... 90 more에러가 납니다. QuerydlsApplicationTests.java는 이렇습니다.ackage study.querydsl;import com.querydsl.jpa.impl.JPAQueryFactory;import jakarta.persistence.EntityManager;import jakarta.transaction.Transactional;import org.assertj.core.api.Assertions;import org.junit.jupiter.api.Test;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.test.context.SpringBootTest;import study.querydsl.entity.Hello;import study.querydsl.entity.QHello;import static org.assertj.core.api.Assertions.*;@SpringBootTest@Transactionalclass QuerydslApplicationTests {@AutowiredEntityManager em;@Testvoid contextLoads() {Hello hello = new Hello();em.persist(hello);JPAQueryFactory query = new JPAQueryFactory(em);QHello qHello = new QHello("h");Hello result = query.selectFrom(qHello).fetchOne();assertThat(result).isEqualTo(hello);assertThat(result.getId()).isEqualTo(hello.getId());}}hello.java 입니다package study.querydsl.entity;import jakarta.persistence.Entity;import jakarta.persistence.GeneratedValue;import jakarta.persistence.Id;import lombok.Getter;import lombok.Setter;@Entity@Getter @Setterpublic class Hello {@Id @GeneratedValue private Long id;}어떻게 해야 하나요?

도서관앱의 포트번호가 8080으로 설정되어 있는것 같은데 포트번호를 변경하는 방법을 모르겠습니다..ㅠ

강사님이 설명해주신 방법이랑 조금 다르게 풀었는데, 계속 오답이 나와서 문의드립니다.어느 부분이 틀린 건지 못찾겠습니다도와주세요..import java.util.Scanner; public class Main { public int[] solution(String str, char c){ int tmp=0; int[] answer = new int[str.length()]; for(int i=0; i<str.length(); i++) { if(str.charAt(i)!=c) { tmp++; } else { tmp=0; } answer[i] = tmp; } for(int i=0; i<answer.length-1; i++) { if(answer[i]!=0 && answer[i+1]==0) { int arrayTmp = answer[i]; for(int j=0 ; j<arrayTmp/2 ; j++) { answer[i-j] = 1 + j; } } } return answer; } public static void main(String[] args) { Main T = new Main(); Scanner scanner = new Scanner(System.in); String str = scanner.next(); char c =scanner.next().charAt(0); for(int a : T.solution(str, c)) { System.out.print(a+ " "); } } }

처음에는 MEMBER_SEQ를 영속성 컨텍스트의 어딘가... 에 저장할거 라고 생각했는데영속성 컨텍스트는 트랜잭션이 커밋될때 같이 종료되기 때문에, 그렇진 않을 것 같다는 생각이 들었습니다. 이러한 방식이면 트랜잭션마다 AllocationSize만큼의 빈 공간이 생기는 사태가 발생하니까요그냥 JPA 내부 Entity의 정보를 저장하는 어딘가에 MEMBER_SEQ도 저장되고, 'call next value for MEMBER_SEQ' 를 호출할 때 마다 같이 수정된다고 보면 되나요?

강의 소스 그대로 참고하여 현재 진행중인 프로젝트에CustomUserDetailsService, CustomAuthenticaionProvider, SecurityConfigure 모두 작성하였습니다.그런데 CustomAuthenticaionProvider의 UserDetailsService와 PasswordEncoder의 @Autowired 부분에서 빨간 줄이 그어져 진행이 불가능합니다. 혹시 스프링 부트 버전차이 때문에 그러는 걸까요?? 현재 2.7.1 사용중입니다.실습한 코드 사진 첨부하도록 하겠습니다.configurecontextcustomUserDetailsServicecustomAuthenticationProvider

강의대로 했는데 안되네요.  우선 깃 링크로 접속하여 코드 다운로드받은뒤 압축풀어서 intellij 로 open 하여 해당 강의처럼 maven -> compile 더블클릭 했는데,  잘 돌던중 에러한줄이 뜹니다. /Users/jjeoV/Desktop/jjeoV/인프런/keesun/studyolle-master 2/target/classes/static/node_modules/.bin/jdenticon jdenticon 파일이 없는건가요? 그냥 딸랑 경로하나뜨니까 뭔지 잘 몰르겠네요.  감사합니다.

 void appendModelName(String modelName) { this.modelName += modelName }인데 어떻게 '까망이 + 까망이' 가 되는게 아니라b1.appendModelName 에 있는 (최신형) 이 붙게 되는걸까요....? append가 인텔리제이에서 제공하는 어떤 함수 같은건가요???