使用RTextArea 遇到的问题

使用RTextArea 遇到的问题

heightTextField = new RTextArea("abc");

运行时报错:

java.lang.NullPointerException
	at javax.swing.text.JTextComponent.setCaretPosition(JTextComponent.java:1680)
	at javax.swing.text.JTextComponent.select(JTextComponent.java:1922)
	at javax.swing.JTextArea.<init>(JTextArea.java:213)
	at javax.swing.JTextArea.<init>(JTextArea.java:150)
	at org.fife.ui.rtextarea.RTextAreaBase.<init>(RTextAreaBase.java:114)
	at org.fife.ui.rtextarea.RTextArea.<init>(RTextArea.java:205)
	at com.swing.dialog.SpecifyWidthAndHeightDialog.<init>(SpecifyWidthAndHeightDialog.java:76)
	at com.swing.dialog.SpecifyWidthAndHeightDialog$1.run(SpecifyWidthAndHeightDialog.java:40)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:312)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
	at java.awt.EventQueue.access$200(EventQueue.java:103)
	at java.awt.EventQueue$3.run(EventQueue.java:694)
	at java.awt.EventQueue$3.run(EventQueue.java:692)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

但是下面的程序是没有问题的:

package com.swing.test;

import com.swing.dialog.GenericFrame;
import org.fife.ui.rtextarea.RTextArea;

import java.awt.*;

/**
 * Created by huangweii on 2016/1/10.
 */
public class TestFrame extends GenericFrame {
    @Override
    public void layout3(Container contentPane) {
        super.layout3(contentPane);
        setLoc(200,200);
        RTextArea rTextArea=new RTextArea();
        rTextArea.setText("文本内容");
        contentPane.add(rTextArea);
    }
    public static void main(String[]args){
        new TestFrame().launchFrame();
    }
}

pom.xml:

 <dependency>
            <groupId>com.fifesoft</groupId>
            <artifactId>rsyntaxtextarea</artifactId>
            <version>r239</version>
        </dependency>