test.java

import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextPane;

public class test
{

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

    private static void buildAndShowGui()
    {

        // Set up the frame
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300, 200);
        frame.setTitle("text");

        // Main panel
        JPanel panel = new JPanel();
        panel.setLayout(new GridBagLayout());

        GridBagConstraints gc = new GridBagConstraints();
        gc.gridx = 0;
        gc.gridy = 0;
        gc.weightx = 500;
        gc.weighty = 500;
        gc.fill = GridBagConstraints.BOTH;

        JScrollPane scrollPane = new JScrollPane();
        JTextPane textPane = new JTextPane();
        scrollPane.setViewportView(textPane);
        panel.add(scrollPane, gc);

        textPane.setText(
                "asoidfaosdijoaisdjodjfodsjfoiadjsfoijdofjdosijfoasdjfoajdsfoijasdofjdoifjaosdfjaodsijfoij\n"
                + "sdandfiunadsiufnasidufidusn\n"
                + "asdfnasdoufn34ejnafdiunadsifunadsiufniuaenifneaiufneiunfiueanfiuaeniuenfe\n"
                + "asdfuioasdfoijasdoifj\n"
                + "adsofijasdofijadosifjoijefmaneoinfaeiounfiuenfiunefinaefoenawofineafoienafoenafiunaeiufneaiufnea\n"
        );

        // Add to frame and display
        frame.add(panel);
        frame.setVisible(true);
    }

}