How to get Logger value in a string array

Question

I used the log4j.Logger and I have written the log value in to a file using the FileAppender.

Now I want to show the log value in a textarea. How can I assign the logger value to an array of Strings?

Answer 1

You can add an additional Appender to your Logger. Use a WriterAppender to write to a StringWriter then you change the content of your TextArea to the value of StringWriter#toString()

Example Code:

public static void main(String[] args) {
    Logger logger = Logger.getLogger("logger");
    Layout layout = new PatternLayout();
    StringWriter stringWriter = new StringWriter();
    WriterAppender writerAppender = new WriterAppender(layout, stringWriter);
    logger.addAppender(writerAppender);
    TextArea textArea = new TextArea();

    logger.error("test");
    //if(stringWriter changed){// compare to old TextArea-content?
      textArea.setText(stringWriter.toString());
    //}
    //System.out.println(stringWriter.toString());
  }

you need to find a smart way update your TextArea depending on the logLevel and if the content of the StringWriter changed.

Update: A comparable solution is presented here.