服务器请求https网站证书不信任 certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

将目标网站的https证书下载到本地，然后导入到 证书列表中，即可正常请求

keytool -import -alias www.xxx.com.cer -keystore $JAVA_HOME/jre/lib/security/cacerts -file www.xxx.com.cer

keystore 的默认密码为：changeit