Using JavaFileObject.openOutputStream is very slow

[oehme]

transfuse/transfuse-core/src/main/java/org/androidtransfuse/gen/FilerSourceCodeWriter.java

Line 53 in a8ee2e9

OutputStream os = sourceFile.openOutputStream();

This method returns an output stream that writes each byte individually, which makes builds very slow. This Javac bug exists all the way up to JDK 15. The FilerOutputStream extends FilterOutputStream without overriding the write(byte[], offset, length) method. I've opened a JDK bug.

In the meantime you can use JavaFileObject.openWriter instead, which does not have this performance problem. You can adapt it back to OutputStream using org.apache.commons.io.output.WriterOutputStream