[LOG4J2-3134] RandomAccessFileAppender does not write headers

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.14.1
• Component/s: Appenders
• Assignee: Unassigned
• Reporter: Yair Halevi
• Created: 09/Aug/21 11:55
• Updated: 09/Aug/21 11:55

Description

When using a `RandomAccessFileAppender` with a layout that includes a header/footer (e.g., a `JsonLayout` with complete=true), the header is not written to the file. 

This seems to be due to `OutputStreamManager.writeHeader` directly writing to the output stream using `os.write` rather than invoking `writeToDestination`. Since the output stream is a `NullOutputStream` when the manager is a RandomAccessFileManager, nothing gets written.

This makes generating complete JSON files in a RandomAccessFileAppender impossible.