How do I write logs and display them real-time in a Java Swing application?

Question

I have created a GUI program that uses a class to perform some tasks.

I would like to add logging in both the JFrame and the class. Logs should be kept in a file and displayed in a JTextArea concurrently.

What is a convient solution for this?

Answer 1

Create a wrapper that

1. updates your JTextArea
2. logs via log4j, SLF4J or Apache Commons Logging or another logging framework

public void log(String msg) {
      appendToJTextArea(msg);
      LOG.info(msg);
 }

Answer 2

I suggest using a simple System.out.println() call and then running your application like this:

java -cp path/to/my/class/or/jar/MyClass.class MyClass -debug > myLog.log

Which will create a text pane for you (-debug parameter), as well as put them in a log file for you.