連線SSL URL出現錯誤 unable to find valid certification path to requested target

參考：SunCertPathBuilderException: unable to find valid certification path to requested target
InstallCert.java

這狀況挺奇怪的，運作已經半年以上的突然出了以下Exception：

javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException:
PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderExce
ption: 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:1937)
        at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302)
        at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296)
        at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.
java:1478)
        at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.jav
a:212)
        at sun.security.ssl.Handshaker.processLoop(Handshaker.java:957)
        at sun.security.ssl.Handshaker.process_record(Handshaker.java:892)
        at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1050)
        at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.
java:1363)

出問題的地方在於我要連結一個https的路徑取回資料，參考解法步驟如下：

1. 將上述連結InstallCert.java 的檔案拿回來存成InstallCert.java
2. 切換到存放InstallCert.java的路徑，使用javac編譯成.class
3. cmd：java InstallCert [your target SSL domain]
   執行第一次的時候會有錯誤。再執行一次就可以（總共執行兩次）
4. 將產生出來的jssecacerts檔案複製到 $JAVA_HOME/jre/lib/secirity
5. restart your service(ex:tomcat)