java.lang.UnsupportedOperationException: This parser does not support specification “null“ version “

編譯OpenJDK8，遇到錯誤：

Generating jfrEventClasses.hpp
java.lang.UnsupportedOperationException: This parser does not support specification "null" version "null"
        at javax.xml.parsers.SAXParserFactory.setSchema(SAXParserFactory.java:394)
        at build.tools.jfr.GenerateJfrFiles$Metadata.<init>(GenerateJfrFiles.java:114)
        at build.tools.jfr.GenerateJfrFiles.main(GenerateJfrFiles.java:43)      

需要複制xerces.jar到編譯的jre/lib/ext目錄下。具體參考：

https://quantum6.blog.csdn.net/article/details/110426862