[newbie] Syntax error on token(s), misplaced construct(s)

[Jon Camilleri]

In this snippet I think I declared textArea before so why am I getting a syntax error?

    
TextComponentFrame.java
package homenetwork.bkr.training;

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

@SuppressWarnings("serial")
public class TextComponentFrame extends JFrame {
	public TextComponentFrame()
	{
		setTitle("Text Component Test");
		setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
		
		final JTextField textField = new JTextField();
		final JPasswordField passwordField = new JPasswordField();
		
		JPanel northPanel = new JPanel();
		northPanel.setLayout(new GridLayout(2,2));
		northPanel.add(new JLabel("User name: ", SwingConstants.RIGHT));
		northPanel.add(textField);
		northPanel.add(new JLabel("Password: ", SwingConstants.RIGHT));
		northPanel.add(passwordField);
		
		add(northPanel, BorderLayout.NORTH);
		
		final JTextArea textArea = new JTextArea(8,40); //here I declare textArea
		JScrollPane scrollPane = new JScrollPane(textArea);
		
		add(scrollPane,BorderLayout.CENTER);
		
		//add button to append text into the text area
		JPanel southPanel = new JPanel();
		JButton insertButton = new JButton("Insert");
		southPanel.add(insertButton);
		
		insertButton.addActionListener(new ActionListener()
			{
				public void actionPerformed(ActionEvent event)
				{
					textArea.append("User name: " + textField.getText() + "Password: " + 
							new String(passwordField.getPassword()) + "\n" );
					//Error: Syntax error on token(s), misplaced construct(s)
				}
			}
		);
		
		add(southPanel,BorderLayout.SOUTH);
		
	}
	
	public static final int DEFAULT_WIDTH = 300;
	public static final int DEFAULT_HEIGHT = 300;

}


TextComponentTest.java
package homenetwork.bkr.training;

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

public class TextComponentTest {
	
	public static void main (String[] args) {
		EventQueue.invokeLater(new Runnable()
		{
			public void run()
			{
				TextComponentFrame frame = new TextComponentFrame();
				frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
				frame.setVisible(true);
			}
		}
		);
	}

}

Output:
Exception in thread "AWT-EventQueue-0" java.lang.Error: Unresolved compilation problem:
ActionListener cannot be resolved to a type

at homenetwork.bkr.training.TextComponentFrame.<init>(TextComponentFrame.java:35)
at homenetwork.bkr.training.TextComponentTest$1.run(TextComponentTest.java:14)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)


NOTE: The tags don't seem to work for bold.

[Jesper de Jong]

Please copy and paste the exact error message that you get, that makes it much easier to help you with this.

NOTE: The tags don't seem to work for bold.

No, ubb tags do not work inside a code block.

[Jesper de Jong]

Aha, I see you edited your post.

ActionListener is in the package java.awt.event, and you're not importing that in your source file. Add this at the top of your source file:

import java.awt.event.ActionListener;

Note that import java.awt.*; does not import everything in package java.awt.event - Java has no subpackages.

The error you get is a little strange, it indicates that you probably have old *.class files lying around. Try deleting them and recompiling everything.

[Jon Camilleri]

Jesper Young wrote:Please copy and paste the exact error message that you get, that makes it much easier to help you with this.

NOTE: The tags don't seem to work for bold.

No, ubb tags do not work inside a code block.

lol...I had a missing import, now it's working thanks anyway

   
package homenetwork.bkr.training;

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

@SuppressWarnings("serial")
public class TextComponentFrame extends JFrame {
	public TextComponentFrame()
	{
		setTitle("Text Component Test");
		setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
		
		final JTextField textField = new JTextField();
		final JPasswordField passwordField = new JPasswordField();
		
		JPanel northPanel = new JPanel();
		northPanel.setLayout(new GridLayout(2,2));
		northPanel.add(new JLabel("User name: ", SwingConstants.RIGHT));
		northPanel.add(textField);
		northPanel.add(new JLabel("Password: ", SwingConstants.RIGHT));
		northPanel.add(passwordField);
		
		add(northPanel, BorderLayout.NORTH);
		
		final JTextArea textArea = new JTextArea(8,40); //here I declare textArea
		JScrollPane scrollPane = new JScrollPane(textArea);
		
		add(scrollPane,BorderLayout.CENTER);
		
		//add button to append text into the text area
		JPanel southPanel = new JPanel();
		JButton insertButton = new JButton("Insert");
		southPanel.add(insertButton);
		
		insertButton.addActionListener(new ActionListener()
		//Error displayed: The type new ActionListener(){} must implement the inherited abstract method ActionListener.actionPerformed(ActionEvent)
			{
				public void actionPerformed(ActionEvent event)
				//Error: ActionEvent cannot be resolved to a type
				{
					textArea.append("User name: " + textField.getText() + "Password: " + 
							new String(passwordField.getPassword()) + "\n" );
					//Error: Syntax error on token(s), misplaced construct(s)
				}
			}
		);
		
		add(southPanel,BorderLayout.SOUTH);
		
	}
	
	public static final int DEFAULT_WIDTH = 300;
	public static final int DEFAULT_HEIGHT = 300;

}

[Rob Spoor]

Jon, you're getting quote some "Unresolved compilation problem" runtime errors (also in other threads). That tells me you are using an IDE (Eclipse, Netbeans, etc) to run your code. I suggest you check the IDE's compiler errors before trying to run. Those will tell you, more or less, what's wrong. Don't run your code until all errors have been resolved.

In your case, the error should be something like "ActionEvent cannot be resolved to a type". And Jesper told you the reason (although he mentioned the wrong class).