问题
I'm trying to make a gui with two menu lists, with 3 items in each. What my problem is, is that when I click on an item, I get an error "The method displayList(int, AirplaneList) is undefined for the type JFrame"
Code for AirplaneController.java:
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import java.util.StringTokenizer;
public class AirplaneController implements ActionListener{
public static StringTokenizer myTokens; //Declares a string tokenizer.
public static String[] animals;
public static int i;//Total including error.
public static int a; //Total strings
final static String[] DATA =
{...
};
final int Cargo = 0;
final int Passenger = 1;
final int Business = 2;
final int All= 4;
int count=0;
AirplaneList close= new AirplaneList();
AirplaneList end=new AirplaneList();
CargoJet Cairplanes[]= new CargoJet[5];
BusinessJet Bairplanes[]= new BusinessJet[5];
PassengerJet Pairplanes[]= new PassengerJet[5];
JFrame gui;
/**
* One-argument constructor that sets the default JFrame and sets
* to listen on buttons of that frame.
* @param frame
*/
public AirplaneController(JFrame frame) {
gui = frame;
//gui.setButtonListener;
}
public void runList(){
Airplane parts2 []= new Airplane[8];
String hate[]= new String [80];
//AirplaneList close= new AirplaneList();
i=0;
animals = new String[80];
for(int i=0; i<8; i++){
myTokens = new StringTokenizer(DATA[i],",");
while (myTokens.hasMoreTokens()) {
animals[a]=myTokens.nextToken();
hate[a]=animals[a];
a++;
}
}
a=0;
int k=0;
int z=0;
int d=0;
for(i=0; i<80; i+=10){
if(hate[i].equals("B")){
Bairplanes[k]= new BusinessJet(hate[i],hate[i+1],hate[i+2],hate[i+3],hate[i+4],hate[i+5],hate[i+6],hate[i+7],hate[i+8],hate[i+9]);
parts2[d]=Bairplanes[k];
d++;
k++;
count++;
}
if(hate[i].equals("C")){
Cairplanes[a]= new CargoJet(hate[i],hate[i+1],hate[i+2],hate[i+3],hate[i+4],hate[i+5],hate[i+6],hate[i+7],hate[i+8],hate[i+9]);// hate[i]="Catastrophy";
parts2[d]=Cairplanes[k];
d++;
a++;
count++;
}
if(hate[i].equals("P")){
Pairplanes[z]= new PassengerJet(hate[i],hate[i+1],hate[i+2],hate[i+3],hate[i+4],hate[i+5],hate[i+6],hate[i+7],hate[i+8],hate[i+9]);// hate[i]="Catastrophy";
parts2[d]=Pairplanes[k];
d++;
z++;
count++;
}
}
for(i=0; i<8; i++){
System.out.println(parts2[i]+" Parts");
close.append(parts2[i]);
}
System.out.println(close);
}
public void createList(int selection) {
int numPlanes = DATA.length;
AirplaneList list = new AirplaneList();
Airplane parts2 []= new Airplane[8];
String hate[]= new String [80];
//AirplaneList close= new AirplaneList();
i=0;
animals = new String[80];
for(int i=0; i<8; i++){
myTokens = new StringTokenizer(DATA[i],",");
while (myTokens.hasMoreTokens()) {
animals[a]=myTokens.nextToken();
hate[a]=animals[a];
a++;
}
}
a=0;
int k=0;
int z=0;
int d=0;
for(i=0; i<80; i+=10){
if(hate[i].equals("B")){
Bairplanes[k]= new BusinessJet(hate[i],hate[i+1],hate[i+2],hate[i+3],hate[i+4],hate[i+5],hate[i+6],hate[i+7],hate[i+8],hate[i+9]);
parts2[d]=Bairplanes[k];
d++;
k++;
count++;
}
if(hate[i].equals("C")){
Cairplanes[a]= new CargoJet(hate[i],hate[i+1],hate[i+2],hate[i+3],hate[i+4],hate[i+5],hate[i+6],hate[i+7],hate[i+8],hate[i+9]);// hate[i]="Catastrophy";
parts2[d]=Cairplanes[k];
d++;
a++;
count++;
}
if(hate[i].equals("P")){
Pairplanes[z]= new PassengerJet(hate[i],hate[i+1],hate[i+2],hate[i+3],hate[i+4],hate[i+5],hate[i+6],hate[i+7],hate[i+8],hate[i+9]);// hate[i]="Catastrophy";
parts2[d]=Pairplanes[k];
d++;
z++;
count++;
}
}
for (int i = 0; i < numPlanes; i++) {
switch (selection)
{
case Business:
list.append(Bairplanes[i]);
break;
case Passenger:
list.append(Pairplanes[i]);
break;
case Cargo:
list.append(Cairplanes[i]);
default:
list.insert(parts2[i]);
}
gui.displayList(selection, list); // PROBLEM HERE!!
}
}
//@Override
/**
* Create a LinkedList of airplane objects either by append, prepend or insert.
* And display the LinkedList on the GUI.
*
* @param selection given order of the LinkedList
* 0 for APPEND, 1 for PREPEND, 2 for INSERT
*/
/*public AirplaneList createList(int selection) {
gui.displayList();
if(selection==All) return close;
return close;
}*/
//gui.displayList(selection, close.toString());
@Override
public void actionPerformed(ActionEvent arg0) {
String item = arg0.getActionCommand();
if (item.equals("Start")){
createList(All);
}
else if(item.equals("Clear")){
}
else if (item.equals("Passenger")){
createList(Passenger);
}
else if( item.equals("Business")){
createList(Business);
}
else if( item.equals("Cargo")){
createList(Cargo);
}
else
System.exit(0);
}
}
The problem is here: gui.displayList(selection, list); and creates this error:
Exception in thread "AWT-EventQueue-0" java.lang.Error: Unresolved compilation problem:
The method displayList(int, AirplaneList) is undefined for the type JFrame
Here's the current code for AirplaneGUI.java:
import java.awt.*;
import javax.swing.*;
import javax.swing.border.Border;
public class AirplaneGUI {
public static void main(String[] args) {
initialize();
}
//JButton[] buttons;
private JMenuBar menuBar;
private JMenuItem item;
JFrame frame;
final Color[] colors = {Color.blue, Color.yellow, Color.green};
JTextArea[] textAreas;
final int NUM_LISTS = 3;
final String[] LIST = {"passenger", "cargo", "bussiness"};
JTextArea spite;
public static void initialize() {
JFrame frame = new JFrame();
frame.setTitle("flight schedule");
frame.setSize(250, 250);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500, 500);
AirplaneController listener = new AirplaneController(frame);
listener.runList();
JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu("File");
JMenuItem startItem = new JMenuItem("Start");
startItem.addActionListener(listener);
menu.add(startItem);
JMenuItem clearItem = new JMenuItem("Clear");
clearItem.addActionListener(listener);
menu.add(clearItem);
JMenuItem exitItem = new JMenuItem("Exit");
exitItem.addActionListener(listener);
menu.add(exitItem);
JMenu menu1 = new JMenu("Filter");
JMenuItem passengerItem = new JMenuItem("Passenger");
passengerItem.addActionListener(listener);
menu1.add(passengerItem);
//frame.setBackground(Color.blue);
JMenuItem bussinessItem = new JMenuItem("Business");
bussinessItem .addActionListener(listener);
menu1.add( bussinessItem );
//frame.setBackground(Color.yellow);
JMenuItem cargoItem = new JMenuItem("Cargo");
cargoItem.addActionListener(listener);
menu1.add(cargoItem);
//frame.setBackground(Color.green);
menuBar.add(menu);
menuBar.add(menu1);
Container pane = frame.getContentPane();
frame.setJMenuBar(menuBar);
frame.setVisible(true);
}
public void setupDisplayPanel() {
Border squareBorder = BorderFactory.createLineBorder(Color.BLACK, 0);
textAreas = new JTextArea[NUM_LISTS];
for (int i = 0; i < NUM_LISTS; ++i) {
textAreas[i] = new JTextArea(LIST[i] + "\n");
textAreas[i].setBorder(squareBorder);
textAreas[i].setBackground(colors[i]);
}
}
public void displayList(int selection, AirplaneList result) {
spite.append(result.toString());
}
public void deleteList(){
spite=null;
}
}
I've tried changing the JFrame gui; in AirplaneController to AirplaneGUI gui;, which then created errors in AirplaneGUI.java:
javax.swing.JFrame cannot be cast to AirplaneGUI
How can I fix this?
回答1:
displayList is a method you have written in AirplaneGUI why do you expect it to be in JFrame? Change JFrame gui; to AirplaneGUI gui; and public AirplaneController(JFrame frame) to public AirplaneController(AirplaneGUI frame).
Having said that there are too many compilation errors and missing classes for me to be able to run it.
May be you need extend JFrame like public class AirplaneGUI extends JFrame{ . I said "may be" because do not get what you are trying to do .
来源：https://stackoverflow.com/questions/30021635/the-method-is-undefined-for-type-jframe