Avoid using default charset when the output stream is a PrintStream

This rule flags the following Java class constructors that take a java.io.OutputStream and no charset :

• java.io.PrintStream
• java.io.PrintWriter
• java.io.OutputStreamWriter

The constructor signatures that take OutputStream without Charset parameters default to use the Charset.defaultCharset() encoding. This causes an issue if the OutputStream to wrap is a PrintStream, which holds its own charset, leading it to ignored. This is especially problematic when PrintWriter wraps System.out/err, because with the JEP400 , the default charset is now UTF-8 while standard I/O remains in native.encoding.

As part of this change, java.io.PrintStream now defines a charset() method to return the print stream's charset.

For more information see JDK-8276970