Scrolling limitation with JScrollPane and JViewport maximum sizes smaller than contents

Question

I have a JFrame containing a JScrollPane containing a JPanel. The JPanel contains a bunch of JTextAreas. I\

Answer 1

Your example is incorrectly synchronized in that it updates jTextArea2 on the initial thread. Note that JTextArea#setText() is no longer thread safe. The example below invokes EditorKit#read(), as suggested here, to load the same 27 MB, 176 K line file examined here. This takes a few seconds, about about twice as long as the JTable approach, but scrolling is comparable.

import java.awt.EventQueue;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

/**
 * @see https://stackoverflow.com/a/25691384/230513
 */
public class Test {

    private static final String NAME = "/var/log/install.log";

    private void display() {
        JFrame f = new JFrame("Test");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JTextArea text = new JTextArea(24, 32);
        try {
            text.read(new BufferedReader(new FileReader(NAME)), null);
        } catch (IOException ex) {
            ex.printStackTrace(System.err);
        }
        f.add(new JScrollPane(text));
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(() -> {
            new Test().display();
        });
    }
}