这两天在做cas单点登录,遇到证书问题并完美解决.  

错误日志:

2016-12-19 17:32:09.690 [ERROR] org.jasig.cas.client.util.CommonUtils  - sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
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) ~[na:1.8.0_101]
        at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1949) ~[na:1.8.0_101]
        at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302) ~[na:1.8.0_101]
        at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296) ~[na:1.8.0_101]
        at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1509) ~[na:1.8.0_101]
        at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216) ~[na:1.8.0_101]
        at sun.security.ssl.Handshaker.processLoop(Handshaker.java:979) ~[na:1.8.0_101]
        at sun.security.ssl.Handshaker.process_record(Handshaker.java:914) ~[na:1.8.0_101]
        at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1062) ~[na:1.8.0_101]
        at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375) ~[na:1.8.0_101]
        at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403) ~[na:1.8.0_101]
        at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387) ~[na:1.8.0_101]
        at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:559) ~[na:1.8.0_101]
        at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185) ~[na:1.8.0_101]
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1513) ~[na:1.8.0_101]
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1441) ~[na:1.8.0_101]
        at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254) ~[na:1.8.0_101]
        at org.jasig.cas.client.util.CommonUtils.getResponseFromServer(CommonUtils.java:326) [cas-client-core-3.2.1.jar:3.2.1]
        at org.jasig.cas.client.util.CommonUtils.getResponseFromServer(CommonUtils.java:305) [cas-client-core-3.2.1.jar:3.2.1]
        at org.jasig.cas.client.validation.AbstractCasProtocolUrlBasedTicketValidator.retrieveResponseFromServer(AbstractCasProtocolUrlBasedTicketValidator.java:50) [cas-client-core-3.2.1.jar:3.2.1]
        at org.jasig.cas.client.validation.AbstractUrlBasedTicketValidator.validate(AbstractUrlBasedTicketValidator.java:207) [cas-client-core-3.2.1.jar:3.2.1]
        at org.jasig.cas.client.validation.AbstractTicketValidationFilter.doFilter(AbstractTicketValidationFilter.java:169) [cas-client-core-3.2.1.jar:3.2.1]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.15.jar:8.0.15]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.15.jar:8.0.15]
        at org.jasig.cas.client.util.AssertionThreadLocalFilter.doFilter(AssertionThreadLocalFilter.java:54) [cas-client-core-3.2.1.jar:3.2.1]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.15.jar:8.0.15]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.15.jar:8.0.15]
        at org.jasig.cas.client.util.HttpServletRequestWrapperFilter.doFilter(HttpServletRequestWrapperFilter.java:75) [cas-client-core-3.2.1.jar:3.2.1]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.15.jar:8.0.15]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.15.jar:8.0.15]
        at org.jasig.cas.client.session.SingleSignOutFilter.doFilter(SingleSignOutFilter.java:76) [cas-client-core-3.2.1.jar:3.2.1]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) [tomcat-embed-core-8.0.15.jar:8.0.15]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) [tomcat-embed-core-8.0.15.jar:8.0.15]
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) [tomcat-embed-core-8.0.15.jar:8.0.15]
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) [tomcat-embed-core-8.0.15.jar:8.0.15]
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) [tomcat-embed-core-8.0.15.jar:8.0.15]
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHo