package javax.websocket does not exist

Question

카페 24 JSP 톰캣 호스팅 이용중입니다.

컴파일시 javax package를 찾을수 없다뜨네요 ㅠㅠ 도와주세요

javac -d . -classpath .:/home/tomcat/common/lib/servlet-api.jar Broadsocket.java Broadsocket.java:7: error: package javax.websocket does not exist import javax.websocket.OnClose; ^ Broadsocket.java:8: error: package javax.websocket does not exist import javax.websocket.OnMessage; ^ Broadsocket.java:9: error: package javax.websocket does not exist import javax.websocket.OnOpen; ^ Broadsocket.java:10: error: package javax.websocket does not exist import javax.websocket.Session; ^ Broadsocket.java:11: error: package javax.websocket.server does not exist import javax.websocket.server.ServerEndpoint; ^ Broadsocket.java:13: error: cannot find symbol @ServerEndpoint("/broadcasting") ^ symbol: class ServerEndpoint Broadsocket.java:16: error: cannot find symbol private static Set<Session> clients = Collections ^ symbol: class Session location: class Broadsocket Broadsocket.java:20: error: cannot find symbol public void onMessage(String message, Session session) throws IOException { ^ symbol: class Session location: class Broadsocket Broadsocket.java:34: error: cannot find symbol public void onOpen(Session session) { ^ symbol: class Session location: class Broadsocket Broadsocket.java:41: error: cannot find symbol public void onClose(Session session) { ^ symbol: class Session location: class Broadsocket Broadsocket.java:19: error: cannot find symbol @OnMessage ^ symbol: class OnMessage location: class Broadsocket Broadsocket.java:33: error: cannot find symbol @OnOpen ^ symbol: class OnOpen location: class Broadsocket Broadsocket.java:40: error: cannot find symbol @OnClose ^ symbol: class OnClose location: class Broadsocket Broadsocket.java:17: error: cannot find symbol .synchronizedSet(new HashSet<Session>()); ^ symbol: class Session location: class Broadsocket Broadsocket.java:25: error: cannot find symbol for (Session client : clients) { ^ symbol: class Session location: class Broadsocket 15 errors

Answer 1

정확한 java 버전과 tomcat 버전이 없어 올리신 내용만 보고 말씀드리면 해당 package가 java classpath 내에 존재하지 않는 문제입니다.

컴파일을 위해 classpath 에 넣으신 servlet-api.jar 내에는 websocket 관련 package가 존재하지 않는것 같습니다.

websocket 관련 package는 별도 javax.websocket client jar를 다운받으셔서 java 가 설치된 폴더의 jre/lib/ext 폴더에 넣으시거나

classpath 가 지정된 곳에 넣으시고 컴파일 하시면 되겠습니다.

인터넷에 다운받으실 곳은 많이 있습니다만, 제가 알고 있는 jar 관련 사이트 링크 드립니다. jar 다운받아서 컴파일 해보시기 바랍니다.

https://jar-download.com/artifacts/javax.websocket/javax.websocket-client-api