在Ubuntu機器上用apt 裝完OpenJDK 11後，按照Jenkins官方文檔按照Jenkins，啓動之後出現以下錯誤：
安裝：
# 安裝JDK11
add-apt-repository ppa:openjdk-r/ppa
apt install openjdk-11-jdk
#安裝Jenkins
wget -q -O - https://pkg.jenkins.io/debian/jenkins.io.key | sudo apt-key add -
sudo sh -c 'echo deb http://pkg.jenkins.io/debian-stable binary/ > /etc/apt/sources.list.d/jenkins.list'
sudo apt-get update
sudo apt-get install jenkins
錯誤：
2020-05-08 04:31:09.838+0000 [id=48] INFO hudson.util.Retrier#start: The attempt #1 to do the action check updates server failed with an allowed exception:
java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty
at java.base/java.security.cert.PKIXParameters.setTrustAnchors(PKIXParameters.java:200)
at java.base/java.security.cert.PKIXParameters.<init>(PKIXParameters.java:120)
at java.base/java.security.cert.PKIXBuilderParameters.<init>(PKIXBuilderParameters.java:104)
at java.base/sun.security.validator.PKIXValidator.<init>(PKIXValidator.java:86)
Caused: java.lang.RuntimeException: Unexpected error
at java.base/sun.security.validator.PKIXValidator.<init>(PKIXValidator.java:89)
at java.base/sun.security.validator.Validator.getInstance(Validator.java:181)
at java.base/sun.security.ssl.X509TrustManagerImpl.getValidator(X509TrustManagerImpl.java:300)
at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrustedInit(X509TrustManagerImpl.java:176)
at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:189)
at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:129)
at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.checkServerCerts(CertificateMessage.java:625)
at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.onCertificate(CertificateMessage.java:460)
at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.consume(CertificateMessage.java:360)
at java.base/sun.security.ssl.SSLHandshake.consume(SSLHandshake.java:392)
at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:443)
at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:421)
at java.base/sun.security.ssl.TransportContext.dispatch(TransportContext.java:177)
at java.base/sun.security.ssl.SSLTransport.decode(SSLTransport.java:164)
at java.base/sun.security.ssl.SSLSocketImpl.decode(SSLSocketImpl.java:1152)
at java.base/sun.security.ssl.SSLSocketImpl.readHandshakeRecord(SSLSocketImpl.java:1063)
at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:402)
Caused: javax.net.ssl.SSLException: Unexpected error: java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty
at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:133)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:320)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:263)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:258)
at java.base/sun.security.ssl.SSLSocketImpl.handleException(SSLSocketImpl.java:1314)
at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:408)
at java.base/sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:567)
at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1587)
at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1515)
at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:250)
at hudson.model.DownloadService.loadJSON(DownloadService.java:114)
at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:208)
at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:203)
at hudson.PluginManager.checkUpdatesServer(PluginManager.java:1765)
at hudson.util.Retrier.start(Retrier.java:63)
at hudson.PluginManager.doCheckUpdatesServer(PluginManager.java:1736)
at jenkins.DailyCheck.execute(DailyCheck.java:93)
at hudson.model.AsyncPeriodicWork.lambda$doRun$0(Async
解決方法：
網上很多的方法包括Stackoverflow上的高贊回答都無法解決，最簡單的方法是從https://jdk.java.net/java-se-ri/11下載OpenJDK 11包，解壓其中的lib/security/cacerts 替換 /etc/ssl/certs/java/cacerts 就OK 了。
參考：https://askubuntu.com/a/991636