• 0

JAVA GUI error message


Question

package Lab4;

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;


public class GUI_Element implements ActionListener{
    // Create a frame window

    public static final int WIDTH = 500;
    public static final int HEIGHT = 400;
    public static final int NUMBER_OF_DIGITS = 30;

    private JTextField ioField;
    private double result = 0.0;

    public GUI_Element () {
        JFrame frame = new JFrame ("Mortgage Calculator");
        frame.setSize (WIDTH, HEIGHT);
        frame.setLayout(new GridLayout(7,1,10,10));
}

Okay so I have this java program written. i'm trying to build a GUI for the first time, so just a beginner at this and I'm using Netbeans.

I get this error on the class name GUI_Element

GUI_Element is not abstract and does not override abstract method actionPerformed in java.awt.event.ActionListener

I have no idea why I'm getting this error.

Please help

Link to comment
https://www.neowin.net/forum/topic/886128-java-gui-error-message/
Share on other sites

10 answers to this question

Recommended Posts

  • 0

I dont mess with gui at all but it could be that you need super() in your constructor as the class is implementing the awt.

^ thats not it.

you could just make the class abstract and implement everything that is needed in your constructor.

public abstract class GUI_Element implements ActionListener{

  • 0

Your class GUI_Element implements an interface (ActionListener). ActionListener requires that implementing classes override the method actionPerformed. You need to define a method called actionPerformed.

It must match the signature in http://java.sun.com/javase/6/docs/api/java/awt/event/ActionListener.html .

so something like:

public void actionPerfomed(ActionEvent e){
   if(e.getSource()==jButton1){
      //do work
   }
}

  • 0

Okay so after adding more code to my file, this is what I ended up with. It looks right to me but the only thing that I need is to make the text field, button smaller so that I can fit the outputs on the same window. I have in all 7 outputs. In the picture I've only shown 2 for now.

Is there a way to make the textfield and button smaller?

Thanks.

post-234729-12694907304266.jpg

  • 0

A GridLayout will make every Component in the Grid the same size no matter what. GridBagLayout will let you set relative sizes, but it's somewhat difficult to figure out. The best bet if you don't want to code the GUI by hand is to use NetBeans IDE. It has a drag-and-drop GUI creator.

Otherwise, you'll want to read this: http://java.sun.com/docs/books/tutorial/uiswing/layout/visual.html

  • 0

^ Thanks for the link. I tried using BorderLayout in mine.

Seems okay to me till now.

Now where I'm stuck is, I want the text "Status of the Program: Waiting for user to enter all the values" to fit on the window. However, my GUI cuts it off. I have no idea how to make it not cut the text I've written.

Any help please?

Thanks :)

post-234729-12695709436469.jpg

  • 0

I don't quite understand how we use HTML tags. Can you give me a link that will make things more clearer?

I'm building on Netbeans. I have an assignment and its due tomorrow :(. I can't use the Netbeans GUI builder. I have to write all the code myself.

Thanks for the help :)

EDIT:

nvm I found this link:

http://java.sun.com/docs/books/tutorial/uiswing/components/html.html

Thanks for the kind help dontocsata!

EDIT2:

okay still stuck. So I have this:

        status.setText(" <html><b>Status of the Program: Waiting for user </b> <b>to enter all the values</b>");

where status is a JLabel.

HTML doesn't seem to work in this.

I don't really know if I'm right though.

This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Posts

    • This site is just old men ranting at clouds. Neowin knows its audience.
    • That's nice and all. but I generally just stick with Lutris paired with 'ge-proton' (which gets updated fairly often (June 1st was last update) as the 'ge-proton' entry in Lutris uses stuff here... https://github.com/GloriousEggroll/proton-ge-custom/releases ) and the like to play my games. p.s. if a person wants to stick with a specific version from that link you can download a specific version and extract it to "~/.local/share/lutris/runners/proton/". then select it in Lutris options on game shortcut is the basic idea. because by default the standard 'ge-proton' entry will automatically get updated which can occasionally cause issues even though it's usually fine. but manually setting it on a specific version will prevent the standard updates on 'ge-proton' from messing with it on a particular game you may have issues with if that gets updated etc. one good example of the 'ge-proton' updates messing with a game in particular is the offline version of RDR2 1491.50 as I setup a specific version there and after removing the 'vulkan-1 (native)' entry in 'Wine configuration' on 'RDR2.exe' entry (if you don't remove this the game won't start up) is when the 'ge-proton' updates, it will restore that 'vulkan-1 (native)' entry and prevent the game from working. you can always remove the entry on the RDR2.exe in Wine configuration specifically after updates, but doing that everytime that updates will get old quickly. hence, keeping it on a specific GE Proton version stops me from having to mess with it as then you just adjust it once and you are done with it. also, when using 'bat' files to start a game (like Hitman: WoA for example using Peacock etc) I had some issues with GE Proton after '9-27', so I got the game locked to '9-27' (April 1st) instead of the newer ones (10-1 etc).
    • Sam Altman says AI could soon help with discovering new knowledge by Hamid Ganji OpenAI is currently at the forefront of developing powerful AI models, while its ChatGPT product is rewriting our traditional way of looking for new information. The company's CEO, Sam Altman, now says AI could even help humans discover new knowledge. He also described AI agents as junior employees. Speaking at the Snowflake Summit 2025, Altman boasted that AI agents can act like junior employees, saying, "You hear people that talk about their job now is to assign work to a bunch of agents, look at the quality, figure out how it fits together, give feedback, and it sounds a lot like how they work with a team of still relatively junior employees." OpenAI CEO also added AI agents could help humans discover new knowledge in "limited cases" or "figure out solutions to business problems that are kind of very non-trivial." While the use of AI for scientific discovery is still viewed with skepticism, the technology has proven its capabilities for new discoveries in several cases. For example, the Microsoft Discovery platform, designed for accelerating scientific research and development by AI agents, was recently able to discover a new chemical for cooling data centers in just 200 hours, a process that normally takes years to research and complete by humans. AI firms are also shifting their focus toward developing AI agents capable of performing various tasks. OpenAI recently unveiled Codex, which contains AI agents for helping programmers write and debug code. According to Altman, OpenAI engineers are already using Codex. As AI agents become more intelligent, more employees should be concerned about losing their jobs. Companies have already started replacing some specific roles with AI. For example, Duolingo has replaced its contract workers with AI, while Shopify managers need to provide reasons why AI cannot handle a job before seeking approval for new hires. Via: Business Insider
    • I personally don't think there will be many survivors past the ESU date, but I can be wrong🙂 >Firefox still supports Windows 7 (until the end of August), which will be just over 16 years since release. Well, yes, but it's an ESR version, which kind of doesn't count as fresh for me. So the last mainline version of Firefox with W7 support was 115, which was released in 2023, exactly around the W7 ESU expiration.
    • Hey, sounds like it’s definitely time for an upgrade. The R7000 had an excellent run! If you want lots of wired ports and future-proofing, the Asus RT-BE88U is a killer choice. It’s got 2x 10GbE, 4x 2.5GbE, and handles WiFi 7 like a champ. Super fast, stable, and the ASUS firmware is solid with loads of features. The TP-Link BE900 is also great, sleek design, strong performance, and a combo 10G port (RJ45/SFP+), but it has fewer wired ports than the Asus. Netgear RS700S is powerful too, but the firmware isn’t as flexible and only has one 10G port. It might feel familiar from your R7000. If wired ports are a big deal, maybe adding a 2.5G or 10G switch later gives you more options. My vote is RT-BE88U all the way.
  • Recent Achievements

    • First Post
      nothin earned a badge
      First Post
    • Enthusiast
      Epaminombas went up a rank
      Enthusiast
    • Posting Machine
      Fiza Ali earned a badge
      Posting Machine
    • One Year In
      WaynesWorld earned a badge
      One Year In
    • First Post
      chriskinney317 earned a badge
      First Post
  • Popular Contributors

    1. 1
      +primortal
      186
    2. 2
      ATLien_0
      130
    3. 3
      snowy owl
      129
    4. 4
      Xenon
      119
    5. 5
      +FloatingFatMan
      97
  • Tell a friend

    Love Neowin? Tell a friend!