Java System.out重定向问题

Question

I've written an recursive directory search that, for each dir that matches a certain pattern, will execute a .bat. Now I want to redirect messages printed to the java console (no need to write standardErr) to an JTextArea. The following code is for the redirection part of the GUI.

taConsole = new JTextArea();
taConsole.setEditable(false);
PrintStream printStream = new PrintStream(new CustomOutputStream(taConsole));
JScrollPane consolePane= new JScrollPane(taConsole);
System.setOut(printStream);

The recursive search and process execution is ok, but when I try to execute with GUI nothing is written on the textarea. When I inserted some System.out.println("foobar") into the GUI class, the messages were printed into the text area as expected. However the prints on my logic class are not being inserted into the textarea.

The program prints a message before and after the bat execution, as follows:

System.out.println("Generating PDFs for"+grandparent+"\\"+parent+"\\ ..."+f.getName());
Process p = Runtime.getRuntime().exec("cmd /c start /wait .\\Run.bat \""+f.getParent()+"\"");
p.waitFor();
System.out.println("PDFs generated!");

The (not so) funny thing is that, when i remove the "start" statement from the command line, the messages are printed in the textarea as I want, but the process is not executed. With the start statement, the program executes and generates my pdfs normally, but no messages are printed to text area at all.

What am I missing here?

Thanks in advance.

SOLVED:

the actual problem was that the main thread for the swing GUI was getting blocked waiting for the recursive search (and PDF generating) to end, so the frame wasn't being refreshed. Solved by implementing Runnable on the logic class and calling it through a new thread in the GUI.

Answer 1

try

new PrintStream(new CustomOutputStream(taConsole), true);

or flush after every println