new JTextArea(SomeStr, 10, 10, JTextArea.SCROLLBARS_VERTICAL_ONLY);
creates a horizontal scrollbar.

import com.sun.java.swing.*;
import java.awt.*;

public class test4 extends JFrame {

    public test4() {
        setLayout(new BorderLayout());
        String SomeStr = "hello";
        JTextArea myTextArea = new JTextArea(SomeStr, 10, 10, JTextArea.SCROLLBARS_VERTICAL_ONLY);
        add("Center", myTextArea);
    }

    public static void main(String args[]) {
        test4 myWindow = new test4();
        myWindow.setTitle("My JTextArea Example");
        myWindow.pack();
        myWindow.show();
    }
}