금일부터 카카오톡 간편 로그인이 되지 않습니다

ID 340611 입니다.
간편 로그인이 동작을 하지 않습니다.
바뀐게 없어서 문의드립니다.

안녕하세요.

오늘 로그를 보니 로그인이 정상 처리되는 것으로 확인되는데요.

관련 화면 캡쳐나 에러 메시지 첨부 부탁드립니다.

10월 28, 2021 10:48:36 오전 org.apache.catalina.core.StandardWrapperValve invoke
심각: Servlet.service() for servlet [jsp] in context with path [] threw exception [java.lang.StringIndexOutOfBoundsException: String index out of range: -1] with root cause
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
at java.lang.String.substring(String.java:1911)
at org.apache.jsp.inc.memberProc.login_005fkakao_005fproc_jsp.getMapToJsonString(login_005fkakao_005fproc_jsp.java:1218)
at org.apache.jsp.inc.memberProc.login_005fkakao_005fproc_jsp._jspService(login_005fkakao_005fproc_jsp.java:2320)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:744)

10월 28, 2021 10:48:37 오전 org.apache.catalina.core.StandardWrapperValve invoke
심각: Servlet.service() for servlet [jsp] in context with path [] threw exception [java.lang.StringIndexOutOfBoundsException: String index out of range: -1] with root cause
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
at java.lang.String.substring(String.java:1911)
at org.apache.jsp.inc.memberProc.login_005fkakao_005fproc_jsp.getMapToJsonString(login_005fkakao_005fproc_jsp.java:1218)
at org.apache.jsp.inc.memberProc.login_005fkakao_005fproc_jsp._jspService(login_005fkakao_005fproc_jsp.java:2320)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:744)

안녕하세요.

아래 공지사항 확인해보시겠어요?

https://devtalk.kakao.com/t/open-api-ssl-urgent-notice-replacing-ssl-certificates-in-kakao-open-api-platform-revised-need-to-recheck/117933

API호출 하는 방식으로 아래 주소 GET방식으로 호출이 되는지 테스트 해보시면 인증서 문제인지 쉽게 확인 가능합니다.

https://test-kapi.kakao.com/test-ca-certificates

kakao

이런식으로 넘어오는데 바뀐게 없는 웹쪽에선 응답이 없어 값이 맞는지 문의드립니다.

캡쳐해주신 화면 크롬 익스텐션으로 KOE006에러 확인을 위한 팝업 내용 같은데요.
위에 기재해주신 로그는 Backend 로그이구요.
__

(1) Backend에서 API호출이 안되신다면,

API호출하시는 방식과 동일하게 아래주소를 Get방식으로 호출 테스트 해주세요. OK응답이 온다면 인증서 문제는 아닙니다.

https://test-kapi.kakao.com/test-ca-certificates

(2) Frontend에서 JS SDK로 카카오 로그인하는 것은 인증서 문제와 관계없이 작동됩니다.

어떤 상황이신지 파악할 수 없는데요. 에러를 재현 할 수 있는 URL알려주시겠어요?

https://bravogolf.co.kr/kr/m/member/login.jsp

에서 카카오톡 로그인을 누르면 서버에서 3번째 댓글처럼 에러가 나오는데 정작 login_kakao_proc.jsp 까지는 넘어오지는 않습니다.

function kakaoLogin() {
        // 로그인 창을 띄웁니다.
        Kakao.Auth.login({
          success: function(authObj) {
            $.ajax({
                url : "/inc/memberProc/login_kakao_proc.jsp",
                method : "post",
                data : {access_token: authObj.access_token},
                dataType : "json",
                success : function(result) {
                    console.log(result);
                    if(result.result && result.result == "success") {
                        location.replace("../");
                    } else {
                        alert(result.resultMsg);
                    }
                },
                error : function(err) {}
            });
          },
          fail: function(err) {
          }
        });
      };

이런식으로 호출하고 있습니다

재현 보니
카카오 로그인 이후 “/inc/memberProc/login_kakao_proc.jsp” 에서 500 에러가 발생하네요.

Failed to load resource: the server responded with a status of 500 (Internal Server Error)

어떤에러인지 먼저 확인해보셔야 할 것 같습니다.

이게 3년 넘게 쓰는 코드인데 어제부터 갑자기 안됩니다.
해당 부분이 고쳐진적도 없고요;;;

최근 애플이 9월 2일 Symantec 계열 루트 인증서 9개를 (macOS/iOS) 루트 저장소에서 삭제한다는 내용을 인증서 발급기관을 통해 전달받아. 인증서교체하게 되었는데요.

갑자기 그렇다면 인증서가 원인일 수 있으니 위에 기재드린 테스트 URL을 카카오 API호출하시는 것과 동일하게 호출해보시고 OK응답이 안온다면


Java: JRE 1.8.0_101 이상, ca-certificates-2015.2.4-65.0.1.el6_6.noarch 이상 버전으로 업데이트하시거나

[긴급공지] 카카오 Open API 플랫폼 SSL 인증서 변경 안내 (수정됨, 재확인 필요) / [Urgent Notice] Replacing SSL certificates in Kakao Open API Platform (Revised, Need to recheck)


https://www.digicert.com/kb/digicert-root-certificates.htm

에서 루트 인증서 받으시고 아래 게시물 참고하셔서 설치 부탁드립니다.

https://www.sslcert.co.kr/guides/kb/47

20211028150250
해당 루트인증서가 설치가 안되네요

인증서 설치전에 아래 테스트 주소 정상 호출되시는지 확인해보셨을까요?

https://test-kapi.kakao.com/test-ca-certificates

어떻게 하는지 몰라 확인중에 있습니다.

10월 28, 2021 4:04:30 오후 org.apache.catalina.core.StandardWrapperValve invoke
심각: Servlet.service() for servlet [jsp] in context with path [] threw exception
java.io.IOException: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:467)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:744)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1884)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:276)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:270)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1341)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:153)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:868)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:804)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1016)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1312)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1339)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1323)
at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:563)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1300)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:468)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:338)
at org.apache.jsp.inc.memberProc.kakao_005fproc_jsp._jspService(kakao_005fproc_jsp.java:2192)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
… 23 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:385)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292)
at sun.security.validator.Validator.validate(Validator.java:260)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:326)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:231)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:126)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1323)
… 39 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:196)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:268)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:380)
… 45 more

우선 한줄한줄 확인 하고 있는데 위와같은 에러로 바뀌었는데 확인 부탁드립니다.

PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

https://test-kapi.kakao.com/test-ca-certificates 이 주소를 Get으로 호출했을때 발생한 내용인가요?

아니요 원래 String urlStr = “https://kapi.kakao.com/v2/user/me”;
했을떄 나오는 에러이구요

String urlStr = “https://test-kapi.kakao.com/test-ca-certificates”;
System.out.println(urlStr);
URL kUrl = new URL(urlStr);
HttpURLConnection con = (HttpURLConnection) kUrl.openConnection();
con.setRequestMethod(“GET”); // optional default is GET
con.setRequestProperty(“Content-Type”, “application/x-www-form-urlencoded;charset=utf-8”);

      int responseCode = con.getResponseCode();
	  System.out.println(responseCode);	
	  System.out.println(con.getResponseCode());	

같은 부분 위와같이 수정했을때 해당 getResponseCode 코드값은 나오지 않고 에러는 안뜨고 있습니다.

네, 인증서 문제로 보이긴하네요.

루트인증서설치 마무리 하시고 재기동하셔서 확인해보시겠어요?

아까 저부분에서 설치가 안되긴 합니다 아니오로만 나와서요
저게 ssl 인증서와는 상관없는건가요 ?

네. 사이트의 SSL인증서가 아니라 JVM에서 http Request할때 사용할 루트 인증서 설치 작업입니다.

저도 cmd 는 잘 모르기는한데, 검색해보니 아래처럼하네요.
한번 시도해보시겠어요?

이 인증서를 신뢰합니까? [아니오]:  예

인증서가 키 저장소에 추가되었습니다.

네 우선 y 누르니깐 되네요 추가 되었습니다. 현재 윈도우에서 톰캣 재실행 하였는데 에러메세지는 안뜨는데 여전히 로그인은 안되고 있습니다. 댓글이 이제 안달아지네요 ㅜ.ㅜ

10월 28, 2021 4:20:33 오후 org.apache.catalina.core.StandardWrapperValve invoke
심각: Servlet.service() for servlet [jsp] in context with path [] threw exception
java.io.IOException: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:467)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:744)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1884)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:276)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:270)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1341)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:153)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:868)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:804)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1016)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1312)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1339)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1323)
at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:563)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1300)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:468)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:338)
at org.apache.jsp.inc.memberProc.kakao_005fproc_jsp._jspService(kakao_005fproc_jsp.java:2192)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
… 23 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:385)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292)
at sun.security.validator.Validator.validate(Validator.java:260)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:326)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:231)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:126)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1323)
… 39 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:196)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:268)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:380)
… 45 more

위와같은 에러가 나옵니다.
20211028162318

하나 더 궁금한게 int responseCode = con.getResponseCode(); 이값이 null 오는것 같습니다.

con.getResponseCode();
https://test-kapi.kakao.com/test-ca-certificates 주소도 https://kapi.kakao.com/v2/user/me
이것도 둘다 결과값이 안오는것 같습니다.

아래 절차데로 하니 되네요 ㅜ.ㅜ 도움주셔서 감사합니다.