import java.awt.BorderLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;

public class Vorauswahl {

    public Vorauswahl() {
        initGUI();
    }

    private void initGUI() {
        String txt = "Text hier einf\u00FCgen";
        JTextArea area = new JTextArea(txt);
        area.setSelectionStart(txt.indexOf("hier"));
        area.setSelectionEnd(txt.indexOf("hier") + "hier".length());
        area.addMouseListener(new MouseAdapter() {
            public void mousePressed(MouseEvent me) {
                area.setSelectionStart(0);
                area.setSelectionEnd(area.getText().length());
            }
        });
        JFrame frame = new JFrame("Vorauswahl");
        frame.setSize(300, 200);
        frame.add(area, BorderLayout.CENTER);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> new Vorauswahl());
    }
}