This might sound flippant, but PrintStream prints to an OutputStream, and PrintWriter prints to a Writer. Ok, I doubt I’ll get any points for stating the obvious. But there’s more. So, what is the difference between an OutputStream and a Writer? Both are streams, with the primary difference being a OutputStream is a stream of … Read more
Updated answer after learning that OP wants to duplicate streams Since you want to write data in both streams try using TeeOutputStream from Apache Commons. Change your code in second try to try { FileOutputStream fos = new FileOutputStream(f); Runtime.getRuntime().addShutdownHook(new Thread(() -> { try { fos.flush(); } catch (Throwable t) { // Ignore } }, … Read more
I recently ran into this problem and just wanted to mention that since java 7 the process builder api has been expanded. This problem can now be solved with: ProcessBuilder pb = new ProcessBuilder(“yourcommand”); pb.redirectOutput(Redirect.INHERIT); pb.redirectError(Redirect.INHERIT); Process p = pb.start();
Since the API documentation makes no mention of thread safety on the System.out object nor does the PrintStream#println(String) method you cannot assume that it is thread-safe. However, it is entirely possible that the underlying implementation of a particular JVM uses a thread-safe function for the println method (e.g. printf on glibc) so that, in reality, … Read more