안녕하세요 질문이 있습니다. 2분 18초에서  Cinality Of Sets 중 C는 뭔가요? 1의 자리 정수인가요? 한글로 조건 나열법 맞나요?  어려워요 ㅋㅋ;      

싱글톤 패턴을 구현하기 위해 코드를 많이 추가해야하고, DIP원칙을 위반하는 등 여러 문제점을 소개하셨고 스프링 컨테이너는 이 문제점을 모두 해결했다고 설명해주셨는데   어떻게 해결했는지는 다른 강의에서 다뤄지나요? 

선생님 sql 쿼리 순서가  join, where 순서라서 where보다 가능하다면 join으로 걸러주는게 성능상 더 좋다고 알고있습니다. 우선 위 생각이 맞는지 궁금하고  만약 아래 join문에서 모든 컬럼들이 인덱싱 되어 있다고 가정하고  SELECT COUNT(c.createdAt) AS unReads, c.RoomId AS RoomId FROM $chatTableName cLEFT JOIN $chatReadersTableName cr ON // 이렇게 특정한 고정값이 있다면 이것을 앞에 넣는게 성능상 좋을까요?cr.UserId = {특정한 고정값} AND cr.ChatRoomId = c.RoomId AND cr.ChatCreatedAt = c.createdAt // 아니면 이렇게 연계키로 매핑먼저 시켜준다음 걸러주는게 성능상 좋을까요?cr.ChatRoomId = c.RoomId AND cr.ChatCreatedAt = c.createdAt AND cr.UserId = {특정한 고정값} WHERE cr.ChatCreatedAt IS NULLGROUP BY c.RoomId;   둘의 결과가 똑같은 것 같은데 성능상 뭐가 더 좋을지 조언을 듣고싶어 질문드립니다!      

The moment Linda, Cindy, Naomi, and Christy traipsed down Fall 1991 catwalk to the strains of George Nike x Off White Shoes Michael's Freedom! '90, history was made. If you're not acquainted, intarsia is defined by The Fairchild Dictionary of Fashion as decorative colored motifs knitted into a solid color fabric, producing an inlay effect and with patterns on both sides of the fabric being identical. Outside the venues, guests are experimenting with new ideas and vintage classics while they attend shows from and more. The 13-piece collection is made from a mix of certified organic and pre-consumer recycled cotton as well as recycled polyester. Not only did Gucci launch its Adidas collaboration for fall, but those three stripes-along many other sporty looks-made the rounds of street style as well. Say arrivederci! to monochrome dressing. The crowd cheered, and phones were held aloft, and for a moment, the past was forgotten. As a designer, Manning understands trial and error is part of the process, and he isn't afraid to keep exploring himself and his work. My favorite childhood memory is my mom saving enough money to buy satellite television, he remembers on a Zoom call. He opened with pieces that felt instantly recognizable as part of the Wang universe swaggering, broad shoulder leather coats, oversized men's white button ups with bras exposed, roomy jean shorts over pants, slouchy boots, and ruched, fleshy bodysuits. You'd never guess that the stripes that decorate these pieces don't miss the Off White Nike Shoes cape dresses were inspired by data charts about global warming. Milan is once again filled with an array of editors, models, and even national soccer players who've come with their FFP2 masks in hand to attend the week's biggest menswear shows and presentations, from more. First, he thought about which garments had remained central components of a man's wardrobe over the years. As a designer, Manning understands trial and error is part of the process, and he isn't afraid to keep exploring himself and his work. The 13-piece collection is made from a mix of certified organic and pre-consumer recycled cotton as well as recycled polyester. You can save money and closet space while scoring the chance to step out in a truly fabulous piece of clothing. Here, posing as his own muse, Manning offers a look at how he wears his very own Ova bag collection, with help from stylist Emmanuel Rivas and hairstylist Athena.   Paris Fashion Week street style started off with guests attending a tribute to Off-White's and will conclude with showgoers outside fall 2022 runway. Specifically, her new special-edition charm necklace speaks to the Nike x Off-White synergy between her brand and FEED by Lauren Bush Lauren. I've been wearing a lot of vintage military wear, and of course my classic vegan Docs, he says. However, flower crowns, lace bralettes and Aztec prints aren't fantastical enough for the smorgasbord of trends that were birthed during the dulling and unprecedented events we've been surviving. 

xml코드나 자바 코드를 읽어서 BeanDefinition을 만듭니다.   강의에서는 만들어진 BeanDefinition을 스프링 빈으로 등록할 때 두 가지 방법이 있다고 언급했는데 ..   직접 등록하는 방법이 있고 자바Config파일을 사용해 BeanFactory를 통해 등록하는 방법이 있다고 하셨습니다.   그런데 자바Config파일은 BeanDefinition을 만들 때 사용된거 아닌가요? 자바Config파일이 BeanDefinition을 만들 때 사용됐으면 빈을 만들 때도 자바Config파일이 사용되는건가요?   마찬가지로, xml파일을 BeanDefinition을 만들 때 사용했으면 빈을 만들 때도 xml파일이 사용되는건가요?   BeanDefinition을 만드는 작업과 스프링 빈을 만드는 작업이 굳이 분리해 설명하시는 이유를 잘 모르겠습니다.    

 위 사진처럼 blend 기능을 사용했는데 상체하체 분리가 되지 않습니다 이유가 무엇인지 잘 모르겠습니다

Student 클래스에 보시면    public Student() {            korea = new Subject();            math = new Subject();                    }  public Student2 (int id, String name) {            studentID = id;            studentName = name;                        korea = new Subject("국어");            math = new Subject("수학");        }   이렇게 있는데 저기 빨간 글씨인 첫번째 퍼블릭 스튜던트는 없어도 되는거 아닌가요? 두번째 퍼블릭 스튜던트가 있으면 첫번째건 없어도 되는거죠? 또 첫번째가 있다면 두번째가 없어도 되는 거 맞나요? 둘다 있을 필요는 없지 않나요?         

안녕하세요, 강의를 보고 계속 생각해봐도 이해가 가지 않는 부분이 있습니다. draft.hasMorePosts = draft.mainPosts.length < 50; 위 코드는 redux폴더의 post.js파일에서 LOAD_POSTS_SUCCESS 부분입니다.   메인포스트가 50개 이하면 true, 이상이면 false를 해준다고 하셨는데 mainposts는 사람들이 포스트를 계속 쓰다보면, mainposts에 저장이 되어, 언젠가 mainposts의 길이는 50개가 넘어갈텐데, hasMorePosts는 그럼 언제나 false가 되는것 아닌가요? (한번 포스팅하면, 본인이 삭제하기 전까진 mainposts에 들어있기 때문에, 삭제 안하면 mainPosts의 길이가 줄지 않아서) 그렇다면 처음 화면 열었을 때,    useEffect(() => {     dispatch(loadPosts()); }, []); 위에 코드를 적어놨기 때문에 처음에는 저 코드대로 로딩이 되고, 그 이후에는 계속 hasMorePosts는 false이기 때문에 아래코드는  ( if (hasMorePosts && !loadPostsLoading) ) < 이부분 if문에 걸려서 영원히 로딩을 할 수 없지 않나요? useEffect(() => {     function onScroll() {       if (         window.scroll + document.documentElement.clientHeight >         document.documentElement.scrollHeight - 300       ) {         if (hasMorePosts && !loadPostsLoading) {           // mainPosts의 길이가 50개 이하면서, 로딩중이 아닐때만 데이터 불러오기           dispatch({ type: LOAD_POSTS_REQUEST });         }       }     }     window.addEventListener("scroll", onScroll);     return () => {       window.removeEventListener("scroll", onScroll);     };   }, [hasMorePosts]);     너무 이해가 가지 않습니다ㅠㅠ  

개발블로그를 운영하다보면 글을 많이 작성하지 못하는 경우가 발생하는데요 그럴때 어떻게 하면 개발블로그 운영을 잘 할 수 있는지에 대한 피드백이 궁금합니다.

자바닥..?이라고 하신건가??뭐 1분36초쯤에 뭐 보고 하시면 된다고 하셨는데 정확히 뭐라고 하신느지 잘 모르게ㅐㅆ어요 뭘 보라고 하신건가요?  

- 왼쪽에 애플 로고있고, 터미널이 바로 아래에서 보이는 것이 너무 멋있습니다. 해당 환경설정 어떻게 하는지 관련 글 있으면 추천 부탁드립니다!

viewModelScope 가 import 되지 않는데 어떤 문제일까요?ㅜㅜ 강의 2:05 부분입니다!

강의를 따라서 해보던 중 ProxyFactoryConfigV1 까진 잘 실행이 되는데 ProxyFactoryConfigV2부터 아래와 같은 에러가 나서 문의 드립니다. 코드 오타가 있을까봐 제공해주신 소스 코드 ProxyFactoryConfigV2.java와 ProxyApplication.java를 그대로 복사해서 왔지만 잘 안되네요   아래는 제 소스입니다.   https://github.com/YoungKyonYou/Proxy-Study   "C:\Program Files\Java\jdk-11.0.13\bin\java.exe" -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.jmx.enabled=true -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA 2021.3.2\lib\idea_rt.jar=50809:C:\Program Files\JetBrains\IntelliJ IDEA 2021.3.2\bin" -Dfile.encoding=UTF-8 -classpath C:\Users\young\proxy-start\build\classes\java\main;C:\Users\young\proxy-start\build\resources\main;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.projectlombok\lombok\1.18.20\18bcea7d5df4d49227b4a0743a536208ce4825bb\lombok-1.18.20.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-web\2.5.5\c09bf133d22c865d6ce4d67ff48aece7ff1defb1\spring-boot-starter-web-2.5.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-json\2.5.5\11923b2b5ca33c6c849952ed1bd47a77c9ec0a85\spring-boot-starter-json-2.5.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter\2.5.5\8657d6f1f00002e8a839fc35fe2f2cd7fc09b72a\spring-boot-starter-2.5.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-tomcat\2.5.5\3fb58add8060ff5a6a17e08eeabca1e823c2f04a\spring-boot-starter-tomcat-2.5.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework\spring-webmvc\5.3.10\d8a26ccc0fb4788c05eca148be8ee987d554a9d2\spring-webmvc-5.3.10.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework\spring-web\5.3.10\31984cef4b5d38f2711cf870994c43e89619ff4e\spring-web-5.3.10.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.datatype\jackson-datatype-jsr310\2.12.5\a0a9870b681a72789c5c6bdc380e45ab719c6aa3\jackson-datatype-jsr310-2.12.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.module\jackson-module-parameter-names\2.12.5\2c85c2036d0851425a260c01eb5f7ddbed1eeb00\jackson-module-parameter-names-2.12.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.datatype\jackson-datatype-jdk8\2.12.5\6b2f79547d217ad50dfc5b57af7444a3aa583b43\jackson-datatype-jdk8-2.12.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.core\jackson-databind\2.12.5\b064cf057f23d3d35390328c5030847efeffedde\jackson-databind-2.12.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-autoconfigure\2.5.5\350511c5612eea8df4ef0f95e2c1b3ff3ea962e8\spring-boot-autoconfigure-2.5.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot\2.5.5\c6335b6e1aff79b13565890ad833bb8865ae2d50\spring-boot-2.5.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework.boot\spring-boot-starter-logging\2.5.5\2731a074593f6b1089060a4af54ef8eee464d7f0\spring-boot-starter-logging-2.5.5.jar;C:\Users\young\.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\young\.gradle\caches\modules-2\files-2.1\org.springframework\spring-core\5.3.10\4e0b94b1e2d7a7399ecedef03dd676c34133625e\spring-core-5.3.10.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.yaml\snakeyaml\1.28\7cae037c3014350c923776548e71c9feb7a69259\snakeyaml-1.28.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.apache.tomcat.embed\tomcat-embed-websocket\9.0.53\e73e461aa0da6a1779bba31f90011cfbd4e4233\tomcat-embed-websocket-9.0.53.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.apache.tomcat.embed\tomcat-embed-core\9.0.53\3343c5ebe9e66da2f75436569e371920e8db1d55\tomcat-embed-core-9.0.53.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.apache.tomcat.embed\tomcat-embed-el\9.0.53\d2fcc31c3ffad7227fcb14ebffc1ed1ab8b7494\tomcat-embed-el-9.0.53.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework\spring-context\5.3.10\45945cec4c23de39faf98139ad81b59965014ff0\spring-context-5.3.10.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework\spring-aop\5.3.10\de0e0c07193697df7ba5db6086020447fdbcb24d\spring-aop-5.3.10.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework\spring-beans\5.3.10\1ff16eb107dd0411deaffa236467efed44d65c60\spring-beans-5.3.10.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework\spring-expression\5.3.10\7ca7f1b5f7a2a9e335f45ffaeb59995c8ab344bc\spring-expression-5.3.10.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.core\jackson-annotations\2.12.5\52d929d5bb21d0186fe24c09624cc3ee4bafc3b3\jackson-annotations-2.12.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\com.fasterxml.jackson.core\jackson-core\2.12.5\725e364cc71b80e60fa450bd06d75cdea7fb2d59\jackson-core-2.12.5.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\ch.qos.logback\logback-classic\1.2.6\b09efa852337fa0dd9859614389eec58dc287116\logback-classic-1.2.6.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.apache.logging.log4j\log4j-to-slf4j\2.14.1\ce8a86a3f50a4304749828ce68e7478cafbc8039\log4j-to-slf4j-2.14.1.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.slf4j\jul-to-slf4j\1.7.32\8a055c04ab44e8e8326901cadf89080721348bdb\jul-to-slf4j-1.7.32.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.springframework\spring-jcl\5.3.10\747a2d6ba0d8a74c4f90a8c66c221e3084e864ee\spring-jcl-5.3.10.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\ch.qos.logback\logback-core\1.2.6\25be1abb32e870ff042e698a799b56587e0dca9a\logback-core-1.2.6.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.slf4j\slf4j-api\1.7.32\cdcff33940d9f2de763bc41ea05a0be5941176c3\slf4j-api-1.7.32.jar;C:\Users\young\.gradle\caches\modules-2\files-2.1\org.apache.logging.log4j\log4j-api\2.14.1\cd8858fbbde69f46bce8db1152c18a43328aae78\log4j-api-2.14.1.jar hello.proxy.ProxyApplication . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.5.5) 2022-08-06 14:17:46.283 INFO 19608 --- [ main] hello.proxy.ProxyApplication : Starting ProxyApplication using Java 11.0.13 on DESKTOP-DH5MQM9 with PID 19608 (C:\Users\young\proxy-start\build\classes\java\main started by young in C:\Users\young\proxy-start) 2022-08-06 14:17:46.287 INFO 19608 --- [ main] hello.proxy.ProxyApplication : No active profile set, falling back to default profiles: default 2022-08-06 14:17:47.182 INFO 19608 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8081 (http) 2022-08-06 14:17:47.194 INFO 19608 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat] 2022-08-06 14:17:47.194 INFO 19608 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.53] 2022-08-06 14:17:47.284 INFO 19608 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2022-08-06 14:17:47.284 INFO 19608 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 932 ms 2022-08-06 14:17:47.371 INFO 19608 --- [ main] h.p.c.v.ProxyFactoryConfigV2 : ProxyFactory proxy=class hello.proxy.app.v2.OrderRepositoryV2$$EnhancerBySpringCGLIB$$f20a709b, target=class hello.proxy.app.v2.OrderRepositoryV2 2022-08-06 14:17:47.376 INFO 19608 --- [ main] h.p.c.v.ProxyFactoryConfigV2 : ProxyFactory proxy=class hello.proxy.app.v2.OrderServiceV2$$EnhancerBySpringCGLIB$$465a9ebe, target=class hello.proxy.app.v2.OrderServiceV2 2022-08-06 14:17:47.379 WARN 19608 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'orderControllerV2' defined in hello.proxy.config.v3_proxyfactory.ProxyFactoryConfigV2: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [hello.proxy.app.v2.OrderControllerV2]: Factory method 'orderControllerV2' threw exception; nested exception is java.lang.ClassCastException: class com.sun.proxy.$Proxy51 cannot be cast to class hello.proxy.app.v2.OrderControllerV2 (com.sun.proxy.$Proxy51 and hello.proxy.app.v2.OrderControllerV2 are in unnamed module of loader 'app') 2022-08-06 14:17:47.382 INFO 19608 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat] 2022-08-06 14:17:47.396 INFO 19608 --- [ main] ConditionEvaluationReportLoggingListener : Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled. 2022-08-06 14:17:47.421 ERROR 19608 --- [ main] o.s.boot.SpringApplication : Application run failed org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'orderControllerV2' defined in hello.proxy.config.v3_proxyfactory.ProxyFactoryConfigV2: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [hello.proxy.app.v2.OrderControllerV2]: Factory method 'orderControllerV2' threw exception; nested exception is java.lang.ClassCastException: class com.sun.proxy.$Proxy51 cannot be cast to class hello.proxy.app.v2.OrderControllerV2 (com.sun.proxy.$Proxy51 and hello.proxy.app.v2.OrderControllerV2 are in unnamed module of loader 'app') at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:658) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:638) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.10.jar:5.3.10] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.10.jar:5.3.10] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.5.jar:2.5.5] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-2.5.5.jar:2.5.5] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) ~[spring-boot-2.5.5.jar:2.5.5] at org.springframework.boot.SpringApplication.run(SpringApplication.java:338) ~[spring-boot-2.5.5.jar:2.5.5] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-2.5.5.jar:2.5.5] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) ~[spring-boot-2.5.5.jar:2.5.5] at hello.proxy.ProxyApplication.main(ProxyApplication.java:33) ~[main/:na] Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [hello.proxy.app.v2.OrderControllerV2]: Factory method 'orderControllerV2' threw exception; nested exception is java.lang.ClassCastException: class com.sun.proxy.$Proxy51 cannot be cast to class hello.proxy.app.v2.OrderControllerV2 (com.sun.proxy.$Proxy51 and hello.proxy.app.v2.OrderControllerV2 are in unnamed module of loader 'app') at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.3.10.jar:5.3.10] at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) ~[spring-beans-5.3.10.jar:5.3.10] ... 19 common frames omitted Caused by: java.lang.ClassCastException: class com.sun.proxy.$Proxy51 cannot be cast to class hello.proxy.app.v2.OrderControllerV2 (com.sun.proxy.$Proxy51 and hello.proxy.app.v2.OrderControllerV2 are in unnamed module of loader 'app') at hello.proxy.config.v3_proxyfactory.ProxyFactoryConfigV2.orderControllerV2(ProxyFactoryConfigV2.java:26) ~[main/:na] at hello.proxy.config.v3_proxyfactory.ProxyFactoryConfigV2$$EnhancerBySpringCGLIB$$9528cf94.CGLIB$orderControllerV2$0(<generated>) ~[main/:na] at hello.proxy.config.v3_proxyfactory.ProxyFactoryConfigV2$$EnhancerBySpringCGLIB$$9528cf94$$FastClassBySpringCGLIB$$1b3baf1f.invoke(<generated>) ~[main/:na] at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.3.10.jar:5.3.10] at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331) ~[spring-context-5.3.10.jar:5.3.10] at hello.proxy.config.v3_proxyfactory.ProxyFactoryConfigV2$$EnhancerBySpringCGLIB$$9528cf94.orderControllerV2(<generated>) ~[main/:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.3.10.jar:5.3.10] ... 20 common frames omitted Process finished with exit code 1          

안녕하세요 강사님~! 강의 잘 보고 있습니다. 다름이 아니라 강사님 코드와 거의 흡사한데, 시간초과가 떠서 뭐가 빠졌나 하고 보니까 ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); 이걸 넣으니 맞았다고 하는데.. 이 코드가 시간초과에 영향이 큰지 여쭤보려고 합니다.. 아래는 시간초과한 코드이고 여기에 상단의 코드를 넣으니 답으로 인정해줬습니다! #include <bits/stdc++.h> using namespace std; int n, m; string buf; map<string, int> mp; map<int, string> rmp; int main() { cin >> n; cin >> m; for (int i = 0; i < n; ++i) { cin >> buf; mp[buf] = i + 1; rmp[i + 1] = buf; } for (int i = 0; i < m; ++i) { cin >> buf; if (atoi(buf.c_str()) != 0) { cout << rmp[atoi(buf.c_str())] << "\n"; continue; } cout << mp[buf] << "\n"; } return 0; }

package hello.servlet.basic.request;import com.fasterxml.jackson.databind.ObjectMapper;import hello.servlet.basic.HelloData;import org.springframework.util.StreamUtils;import javax.servlet.ServletException;import javax.servlet.ServletInputStream;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.nio.charset.StandardCharsets;/** * http://localhost:8080/request-body-json * * JSON 형식 전송 * content-type: application/json * message body: {"username": "hello", "age": 20} * */@WebServlet(name = "requestBodyJsonServlet", urlPatterns = "/request-bodyjson")public class RequestBodyJsonServlet extends HttpServlet { private ObjectMapper objectMapper = new ObjectMapper(); @Override protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ServletInputStream inputStream = request.getInputStream(); String messageBody = StreamUtils.copyToString(inputStream, StandardCharsets.UTF_8); System.out.println("messageBody = " + messageBody); HelloData helloData = objectMapper.readValue(messageBody, HelloData.class); System.out.println("helloData.username = " + helloData.getUsername()); System.out.println("helloData.age = " + helloData.getAge()); response.getWriter().write("ok"); }}이 코드로 제대로 넣었고   postman으로 저렇게 하였는 데 왜  이 오류가 나는 건지 궁금합니다.\

local.properties 에 있는 bookApiKey 값을 Constants  오브젝트에서 bookApiKey 를 인식하지 못합니다. 해결방법이 있을까요?

선생님이 하신 코드 그대로 따라적었는데 실행해보면 12345가 나와야하는데 5만 나옵니다. 중간중간 console.log()로 토탈페이지, 페이지 등등 다 출력해봤는데 정상적으로 값은 출력되는데 최종적으로 실행만 시키면 모든 페이지에서 5 하나만 나와요 어디가 잘못된걸까요..

강의에서 for문을 돌리실 때 for(let i=0; i<n; i++){ for(let j=i+1; j<n; j++){ for(let k=j+1; k<n; k++){ tmp.add(card[i]+card[j]+card[k]); } } } j = i+1, k = j + 1 로 하게 되면 범위가 모든 숫자의 합의 경우의 수가 안나오지 않나요??? 예를 들어 입력 예제를 봤을 때 13 15 34 23 45 65 33 11 26 42 인 경우 13+13+13 같은 경우의 수는 빼고 값을 구하는 건데 문제에선 같은 숫자의 카드가 여러개 있을 수 있다고 되있어서요. 설명 한번만 해주시면 감사하겠습니다ㅠㅠ

59번 문제 for item in dict2.keys():       dict_all[item] = dict2[item] for item in dict3.keys():       dict_all[item] = dict3[item] 이렇게 작성했을때 dict_all[item] = dict2[item] 이 잘 이해가지 않습니다. dict_all[ dict2.keys() ] = dict2[ dict2.keys() ]  이렇게 풀어서 해석하는게 맞는건지 맞다면  둘의 키값은 같다 라고 정했을때 어째서 합쳐지는건지 궁금합니다.

설치된 h2 console을 실행하면 Microsoft edge 브라우져로 연결이 되는데 연결 브라우져를 Chrome으로 변경하는 방법이 있을까요 ?