"non-static ... cannot be referenced from a static..." BUT they're static!

Well, this is starting to get a little frustrating.
I compile and get "non-static method cannot be referenced from a static context", BUT I declared the method as static!!! Why am I still getting this!?!
I'm calling the method from my main, as it is in another class. I've done this before and never ran into problems, but for some reason this time I am. Can anyone let me know what the problem could be and some possible solutions for fixing it.
Thank you so much.

A lot of people don't know this, but whenever you run javac or use a compiler in an IDE, it doesn't actually compile the code. It just packages it up and emails it to an email address at sun.com. There, a Sun developer reads your code and then turns it into bytecode by hand. It seems to go really fast, but that's because it's sent to to hundreds of offshore developers working in parallel. Then the lead developer emails your compiled class file back to javac, which then writes it to disk, unless the developer there had problems, in which case they email you back a list of error messages that javac displays to the screen.
So what happened was, the first time you compiled it, the offshore developers didn't like you personally, so they sent you error messages. But the second time you tried to compile it, they had changed shifts, and the new developers did like you, so they compiled your code.
Your code didn't change, you didn't invoke javac differently, and your code and your skills as a developer are all flawless. It's just a matter of whether the folks doing the compiliation like you.

Similar Messages

Another question: non-static variable super cannot be referenced from ...?

class a
int i;
int j=2;
a(int i)
this.i=i;
public class b extends a
     b()
     super(8);
public static void main(String args[])
b test=new b();
System.out.print(test.i);
test.j=1;
System.out.print("test.j="+test.j);
System.out.print("super.j="+super.j);
b.java:28: non-static variable super cannot be referenced from a static context
System.out.print("super.j="+super.j);
^
1 error
thanks

You cannot call "super" from a static context. Just like you can't use "this" or call any non-static methods in a static context.
Try with test.super.j, although I'm not sure if it works. But you can call super.j in a non-static context, e.g. in your constructor, or in a non-static method.

"non-static variable cannot be referenced from a static contex"

Hi, i'm writing a booking program at school and i'm getting 27 "non-static variable cannot be referenced from a static contex" errors. I can't find anything wrong with the code so I'm just asking you guys to look it through..
public class bokningsmeny
Bokning[] bokningslista = new Bokning[1000];
String fornamn;
String efternamn;
String civilstand;
String adress;
String personnr;
String telefonnr;
int regnr;
double inkomst;
public static void main(String[] args)
for(;;)
System.out.println("\nMeny");
System.out.println("________\n");
System.out.println("1. Mata in nya personer.");
System.out.println("2. Sök personen via personnummer och skriv personens andra uppgifter.");
System.out.println("3. Sök personen via efternamn och skriv personens andra uppgifter.");
System.out.println("4. Sök personen via personnummer och ändra adress.");
System.out.println("5. Sök personen via personnummer och ändra telefonnummer.");
System.out.println("6. Sök personen via personnummer och ändra civilstånd.");
System.out.println("7. Sök personen vis personnummer och ändra inkomst");
System.out.println("8. Skriv ut alla personer med givet namn.");
System.out.println("9. Skriv ut alla personer med givet efternamn");
System.out.println("10. Skriv ut alla personer med given adress");
System.out.println("11. Skriv ut hela listan");
System.out.println("12. Avsluta\n");
int menyval = Keyboard.readInt();
System.out.println("\n");
switch(menyval)
case 1:
System.out.println("Mata in nya personer.\n______________________\n");
boolean BOOuppgifter = false;
for(int i = 0; i <= 1000; i++)
if(bokningslista +== null)+
+{+
+SkrivInUppgifter();+
+System.out.println("\nStämmer informationen? (Y/N)");+
+boolean BOOcase1yesorno = IsInputCorrect();+
+if(BOOcase1yesorno == true)+
+{+
+System.out.println("\nBokningen lyckades!\n");+
+bokningslista += new Bokning(fornamn, efternamn, civilstand, adress, personnr, telefonnr, regnr, inkomst);
++++else if(BOOcase1yesorno == false
++++System.out.println("\nBokningen avbruten.\n")
++++break
++++++break
++++case 2
++++System.out.println("Sok person med personnummer och ändra uppgifter.")
++System.out.println("___________________________________________________________\n")
++System.out.print("Skriv in sokord: ")
++String query = Keyboard.readString()
++query = query.toUpperCase()
++String personnummersok
++boolean contains
++int antal = 0
++boolean BOOcase2result = false
++System.out.println("Resultat: \n_________\n")
++for(int i = 0; i < 1000; i++
++++if(bokningslista +!<b +<em<b +++personnummersok = (bokningslista+.hamtaPersonnum()).t
++++contains = personnummersok.con
++++if(cont
+< ++++BOOcase2r
++++ant
++++fornamn = bokningslist
+++++efternamn = boknin
++++++personnr
+++++++System.out.println(antal + ". " + fornam
++++<e +++++++System.out.pri<br +++++<em +++++++System.out.println("\nVilket sokresultat vill du v&bdquo
++++< +++++++if(case2ch
+++++++System.ou
+++<e< +++<em ++++
++<em +++++++System.out.p
+++++<e +++<<br +++++++System.out.printl
+++<em +++++<em ++
<e ++++++++Sy
+++++
++++++<e <em ++++++++< +++++<e +++
+++< +++++++++else if(case11exit != 'y' &<br +< ++++
++++
+++++
++++<e +++++++
++++<em +++++
+++<em +++++<em ++++< ++++++
++++<e +++++++<e ++<em ++++<e +++< +++++++++System.out.println("\n\nNamn: " + fornamn + "
++++++++++ "\nHemadress: " + adr
++++++++++ telefon
+< +++++++++Syste
++++<em +++++++++if(correct
<em ++<em ++< ++++<e << <e +++++++++I have another file with the Bokning.java class in it but I know for sure that its error free. Notice that I'm not nearly done with the program, theres like 10 more 'cases' to be created but I dont w
++<em

Your code goes "+" crazy there, but here is your problem:
public class B extends A {
 public void method() {}
 public static void main(String[] args) {
 //method(); //non-static method method() cannot be referenced from a static context
 B b = new B();
 b.method();
}You need to be clear about the difference between static methods and non-static (instance) methods. Instance methods are applied to objects.

Non-static variable total cannot be referenced from a static context

i am trying to write a program that uses the if-else statements and when i wrote my program i got "non-static variable total cannot be referenced from a static context" for three lines of my input.
A:\Disks.java:20: non-static variable total cannot be referenced from a static context total = (10000 * .95 + ((diskCount - 10000) * .85));
^
A:\Disks.java:22: non-static variable total cannot be referenced from a static context total = (diskCount * .95);
^
A:\Disks.java:24: non-static variable total cannot be referenced from a static context System.out.print(total);
^
Do you know what I did wrong?

I apologise in advance for the general tone of this reply.....
Ummm, let me think for a second... You referenced a non static
variable from a static context. Yup, yup. That's it !
If you can't figure this out, you really need to do a Java tutorial or
buy a text book. Basically though, total is a member of some class
and you are trying to use it from a static function. I bet you have
something like:
public class Test {
    public int total;
    // blah blah blah
    public static void main(String[] args) {
        // This won't work cos "total" is a member and we are static
        System.out.println(total);
        // This works cos now you have an instance to pull total
        // out of.
        Test t = new Total();
        System.out.println(t.total);
}

Non-static variable aceYears cannot be referenced from a static context

This is my error...
investment.java:53: non-static variable aceYears cannot be referenced from a static context
lwInvest.numberAceYears(aceYears);
^
This is my code...
public static void main (String[] args)
investment.Invest.numberAceYears(aceYears);
and more code
String termInvested = JOptionPane.showInputDialog
("Please enter the amount of years to invest your investment.");
int intTermInvested = Integer.parseInt(termInvested);
and yet more code..
public void numberAceYears (int aceYears)
for (int aY = 5 ; aY <= aceYears; aY++)
double aceInterest = aceCoBalance * aceCoRate /100;
aceCoBalance = aceCoBalance + aceInterest;
aceYears = aceYears + aY;
Suggestions?

Short version: Either make the variable in question static, or create an instance of your class and use that to access it. Either one will work, but one probably suits your design better. It's up to you to figure out which one.
For details, see the relevant section of your favorite Java book or tutorial, or poke around here:
http://www.google.com/search?q=java+non+static+variable+cannot+be+referenced+from+a+static+context

Non-static variable change cannot be referenced from a static context

My compiler says: : non-static variable change cannot be referenced from a static context
when i try to compile this. Why is it happening?
public class change{
int coin[] = {1,5,10,25,50};
int change=0;
public static void main(){
int val = Integer.parseInt(JOptionPane.showInputDialog(null, "Type the amount: ", "Change", JOptionPane.QUESTION_MESSAGE));
change = backtrack();
}

A static field or method is not associated with any instance of the class; rather it's associated with the class itself.
When you declared the field to be non-static (by not including the "static" keyword; non-static methods and fields are much more common so it's the default), that meant that the field was a property of an object. But the static main method, being static, didn't have an object associated with it. So there was no "change" property to refer to.
An alternative way to get this work, would be to make your main method instantiate an object of the class "change", and put the functionality in other instance methods.
By the way, class names are supposed to start with upper-case letters. That's the convention.

Non-static cannot be referenced from a static context - ?

Hi, i understand (kinda) what the error means
i think its saying that i cannot call a non-static method "bubbleSort"
from the static method main (correct?)
but i dont know how to fix it...
do i make bubbleSort
public static void bubbleSort???
C:\jLotto\dataFile\SortNumbers.java:80: non-static method bubbleSort(int[]) cannot be referenced from a static context
 bubbleSort( a ); //sort the array into ascending numbers
my code:
import java.io.*;
import java.util.*;
public class SortNumbers
 public static void main( String args[]) throws IOException
 int num;
 int a[] = new int[7]; //an array for sorting numbers
 File inputFile = new File("C:\\jLotto\\dataFile\\outagain.txt");
 File outputFile = new File("C:\\jLotto\\dataFile\\sortedNum.txt");
 BufferedReader br = new BufferedReader( new FileReader( inputFile ));
 PrintWriter pw = new PrintWriter( new FileWriter( outputFile ));
 String line = br.readLine();
 while( line != null ){//reads a single line from the file
 StringBuffer buffer = new StringBuffer(31); //create a buffer
 StringTokenizer st = new StringTokenizer( line," "); //create a tokenizer
 while (st.hasMoreTokens()){
 // the first 4 tokens are id,month,day,ccyy, no sorting needed
 // so they are simply moved into the buffer
 for (int i =1; i<5; i++){
 num = Integer.parseInt(st.nextToken());
 buffer.append( num );
 buffer.append( "|");
 //tokens 5 to 11 need to be sorted into acending order
 //so read tokens 5 to 11 into an array for sorting
 for (int i =0; i<7; i++){
 a[i] = Integer.parseInt(st.nextToken());
 bubbleSort( a ); //sort the array into ascending numbers
 //the array is sorted so read array back into the buffer
 for ( int i = 0; i < a.length; i++ ){
 buffer.append( a[ i ] );
 buffer.append( "|" ) ;
 }//end of while st.hasMoreTokens
 //then write out the record from the stringBuffer
 pw.println( buffer );
 line = br.readLine();
 }//end of while != null
 br.close();
 pw.close();
 }//end of static main
 // sort the elements of an array with bubble sort
 public void bubbleSort( int b[] )
 int swapMade = 0; //if after one pass, no swaps were made - exit
 for ( int pass = 1; pass < ( b.length - pass) ; pass++ ) // passes reduced for speed
 for ( int i = 0; i < b.length - 1; i++ ) // one pass
 if ( b[ i ] > b[ i + 1 ] ) // one comparison
 swap( b, i, i + 1 ); // one swap
 swapMade = 1;
 } // end of if
 } //end of one pass
 if (swapMade == 0) pass = 7; //no swaps, so break out of outter for loop
 }//end of passes, end of outter for loop
 }//end of bubblesort method
 // swap two elements of an array
 public void swap( int c[], int first, int second )
 int hold; // temporary holding area for swap
 hold = c[ first ];
 c[ first ] = c[ second ];
 c[ second ] = hold;
 } //end of swap
}//end of class SortNumbers

Static means
when u run the program (a class), there is only one variabel / type in memory.
ex static int a; //assume it's inside the aStaticClass
mean no wonder how many u create object from this class, variabel a only have 1 in memory. so if u change a (ex a=1;) all instance of this aStaticClass will effected (because they share the same variabel).
Try to read more at :
http://java.sun.com/docs/books/tutorial/java/javaOO/classvars.html
I hope this will help you....happy new year
yonscun

Non-static method cannot be referenced from a static context....again sry

Hey, I know you guys have probably seen a lot of these, but its for an assignment and I need some help. The error I'm getting is: non-static method printHistory() cannot be referenced from a static context. Here are the classes effected
public class BankAccount {
private static int nextAccountNumber = 1000;
//used to generate account numbers
private String owner; //name of person who owns the account
private int accountNumber; //a valid and unique account number;
private double balance; //amount of money in the account
private TransactionHistory transactions; //collection of past transactions
private Transaction transaction;
//constructor
public BankAccount(String anOwnerName){
owner = anOwnerName;
accountNumber = nextAccountNumber++;
balance = 0.0;
transactions = new TransactionHistory();
//public String getOwner() {
public void deposit(double anAmount ){
 balance=balance+anAmount;
 transaction=new Transaction(TransactionType.DEPOSIT,accountNumber,anAmount,balance);
 transactions.add(transaction);
//public void withdraw(double anAmount){
//public String toString() {
***public void printHistory(){
 TransactionHistory.printHistory();
AND
public class TransactionHistory {
final static int CAPACITY = 6; //maximum number of transactions that can be remembered
//intentionally set low to make testing easier
private Transaction[] transactions = new Transaction[CAPACITY];
//array to store transaction objects
private int size = 0;
//the number of actual Transaction objects in the collection
public void add(Transaction aTransaction){
 if (size>5){
 transactions[0]=transactions[1];
 transactions[1]=transactions[2];
 transactions[2]=transactions[3];
 transactions[3]=transactions[4];
 transactions[4]=transactions[5];
 transactions[5]=aTransaction;
 transactions[size]=aTransaction;
 size=size++;
public int size() {
 return size;
***public void printHistory() {
 for(int i=0;i<6;i++){
 System.out.println(transactions);
//public void printHistory(int n){
The project still isn't finished, so thats why some code is commented out. The line with *** infront on it are the methods directly effected, I think. Any help would be great.

In Java, static means "something pertaining to an object class". Often, the term class is substituted for static, as in "class method" or "class variable." Non-static, on the other hand, means "something pertaining to an actual instance of an object. Similarly, the term +instance+ is often substituted for +non-static+, as in "instance method" or "instance variable."
The error comes about because static members (methods, variables, classes, etc.) don't require an instance of the object to be accessed; they belong to the class. But a non-static member belongs to an instance -- an individual object. There's no way in a static context to know which instance's variable to use or method to call. Indeed, there may not be any instances at all! Thus, the compiler happily tells you that you can't access an instance member (non-static) from a class context (static).
~

Non-static method paint cannot be referenced from static context

i cant seem to figure out this error dealing method paint:
public class TemplateCanvas extends Canvas implements Runnable {
    //static
    public static final int STATE_IDLE      = 0;
    public static final int STATE_ACTIVE    = 1;
    public static final int STATE_DONE      = 2;
    private int     width;
    private int     height;
    private Font    font;
    private Command start;
    private int state;
    private String message;
    public TemplateCanvas() {
        width = getWidth();
        height = getHeight();
        font = Font.getDefaultFont();
        //// set up a command button to start network fetch
        start = new Command("Start", Command.SCREEN, 1);
        addCommand(start);
    public void paint(Graphics g) {
        g.setColor(0xffffff);
        g.fillRect(0, 0, width, height);
        g.setColor(0);
        g.setFont(font);
        if (state == STATE_ACTIVE) {
            Animation.paint(g);
        } else if (state == STATE_DONE) {
            g.drawString(message, width >> 1, height >> 1, Graphics.TOP | Graphics.HCENTER);
    public void commandAction(Command c, Displayable d) {
        if (c == start) {
            removeCommand(start);
            //// start fetching in a new thread
            Thread t = new Thread(this);
            t.start();
    public void run() {
        state = STATE_ACTIVE;
        //// start network fetch
        Network network = new Network();
        network.start();
        //// start busy animation
        Animation anim = new Animation(this);
        anim.start();
        //// wait for network to finish
        synchronized (network) {
            try {
                wait();
            } catch (InterruptedException ie) { }
        //// end animation
        anim.end();
        //// get message from network
        message = network.getResult();
        //// repaint message
        state = STATE_DONE;
        repaint();
}TemplateCanvas.java:38: non-static method paint(javax.microedition.lcdui.Graphics) cannot be referenced from a static context

Animation.paint(g); paint() is not a static method. That means you have to call it on an instance of an Animation class (an object), not on the class itself. This is designed this way because the paint() method uses variables that have to be instantiated, so if you don't have an instance to use, it can't access the variables it needs. Static methods don't use instance variables, they only use what's passed in to them, so they don't need to be called on an object. Hope that was clear.

Non-static method getRealPath cannot be referenced from a static context

Hi, I'm fairly new to java and servlets, I get the following error referencing the line denoted in the code snippet with a ">>" I don't understand why I am getting this error message?
Message: non-static method getRealPath(java.lang.String) cannot be referenced from a static context
public class events extends HttpServlet implements SingleThreadModel {
private static final String CONTENT_TYPE = "text/html";
//Initialize global variables
public Document xmlDocument;
public HttpSession theSession;
public RequestDispatcher pageInit;
public RequestDispatcher pageHeader;
public RequestDispatcher pageFooter;
public String path;
public void setPath(){
path = getServletContext.getRealPath( "/" ); }
public void init() throws ServletException {
}

Ok More Code, I am weary of posting too much? I don't know why come to think of it?
package altitude;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import org.jdom.*;
import altitude.sysVar;
public class events extends HttpServlet implements SingleThreadModel {
private static final String CONTENT_TYPE = "text/html";
//Initialize global variables
public Document xmlDocument;
public HttpSession theSession;
public RequestDispatcher pageInit;
public RequestDispatcher pageHeader;
public RequestDispatcher pageFooter;
public String path;
public void getRealPath(){
    path = ServletContext.getRealPath( "/" );
public void init() throws ServletException {
//Process the HTTP Get request
public void doGet( HttpServletRequest request, HttpServletResponse response ) throws ServletException, IOException {
    //Initialise some Global Variables
    theSession = request.getSession( true );
    doPage( request, response );
//Process the HTTP Post request
public void doPost( HttpServletRequest request, HttpServletResponse response ) throws ServletException, IOException {
    //Initialise some Global Variables
    theSession = request.getSession( true );
    doPage( request, response );
public void doPage( HttpServletRequest request, HttpServletResponse response ) throws ServletException, IOException {
    //Initialise the variables and get the parameters from the query string.
    String eventID = request.getParameter( "eventID" );
    String dateFrom = request.getParameter( "dateFrom" );
    String dateTo = request.getParameter( "dateTo" );
    theSession.setAttribute( "Page Title", sysVar.servletTitle_events);
    Calendar theCalendar = Calendar.getInstance();
    RequestDispatcher pageInit = request.getRequestDispatcher( sysVar.servlet_initSession );
    pageInit.include( request, response );
    RequestDispatcher pageHeader = request.getRequestDispatcher( theSession.getAttribute( "Skin Directory" ) + sysVar.page_header );
    RequestDispatcher pageBody = request.getRequestDispatcher( sysVar.servletJsp_events );
    RequestDispatcher pageFooter = request.getRequestDispatcher( theSession.getAttribute( "Skin Directory" ) + sysVar.page_footer );
    //Initailize the site for this visitor this sets up the skin, and any customisations that may exist.
    //load variables, objects in to the session
    theSession.setAttribute( "Xml Document Object", path + sysVar.data_events );
    pageHeader.include( request, response );
    pageBody.include( request, response );
    pageFooter.include( request, response );
    //remove the variables and the objects from the session
    theSession.setAttribute( "Xml Document Object", "" );
//Clean up resources
public void destroy() {
}

Non-static method getIDnumber() cannot be referenced from a static context

Student.java
public class Student
     private int IDnumber;
     private int hours;
     private int points;
     public Student()
   IDnumber = 9999;
   points = 12;
   hours = 3;
     public void setIDnumber(int number)
     IDnumber = number;
   public int getIDnumber()
     return IDnumber;
   public void setHours(int number)
   hours = number;
   public int getHours()
   return hours;
   public void setPoints(int number)
   points = number;
   public int getPoints()
   return points;
     public void showIDnumber()
   System.out.println("ID Number is " + IDnumber);
   public void showHours()
   System.out.println("Credit Hours are " + hours);
   public void showPoints()
   System.out.println("Points Earned are " + points);
   public double getGradePoint()
   return (double) (points / hours);
ShowStudent.java
public class ShowStudent
     public static void main(String[] args)
          Student learner = new Student();
          int IDnumber;
          int points;
          int hours;
          IDnumber = Student.getIDnumber();
          points = Student.getPoints();
          hours = Student.getHours();
          System.out.println("ID number is " + IDnumber);
          System.out.println("Hours are " + hours);
          System.out.println("Points are " + points);
Here I get the following. How do I fix this? Thanks.
ShowStudent.java:9: non-static method getIDnumber() cannot be referenced from a
static context
IDnumber = Student.getIDnumber();
^
ShowStudent.java:10: non-static method getPoints() cannot be referenced from a
static context
points = Student.getPoints();
^
ShowStudent.java:11: non-static method getHours() cannot be referenced from a s
tatic context
hours = Student.getHours();
^
3 errors

You have to get the ID number of a particular instance i.e. IDnumber = learner.getIDnumber();

Non-static method getPerimeter() cannot be referenced from a static context

I am getting this error message. I assume it is because getArea( ) and getPerimeter( ) are nonstatic and main is static? Can somebody help me? Thanks in advance!
Error messages:
non-static method getArea() cannot be referenced from a static context
          System.out.println("\nArea: " + onePlace.format(getArea()));
non-static method getPerimeter() cannot be referenced from a static context
          System.out.println("Perimeter: " + onePlace.format(getPerimeter()));
import java.util.Scanner;
import java.text.DecimalFormat;
public class Rectangle
     public double length;
     public double width;
     public Rectangle()
          length = 0;
          width = 0;
     public double getLength()
          return length;
     public double getWidth()
          return width;
     public void setLength(double length)
          this.length = length;
     public void setWidth(double width)
          this.width = width;
     public double getArea()
          return (length * width);
/*     public double area(Rectangle R)
          double area = length * width;
          return area;
     public double getPerimeter()
          return ((length * 2) + (width * 2));
/*     public double perimeter(Rectangle R)
          double perimeter = (length * 2) + (width * 2);
          return perimeter;
/*     public String toString()
          double area = 0;
          double perimeter = 0;
          return "Area: " + area + "\tPerimeter: " + perimeter;
     public static void main(String [] args)
          DecimalFormat onePlace = new DecimalFormat("#0.0");
          Rectangle R = new Rectangle();
          Rectangle L = new Rectangle();
          Rectangle W = new Rectangle();
          Scanner input = new Scanner(System.in);
          System.out.println("Enter length of rectangle: ");
          L.setLength(input.nextDouble());
          System.out.println("\nEnter width of rectangle: ");
          W.setWidth(input.nextDouble());
          System.out.println("\nArea: " + onePlace.format(getArea()));
          System.out.println("Perimeter: " + onePlace.format(getPerimeter()));
//          System.out.println(R.toString());
}

For some reason, something isn't being read.
This is what I get:
Enter length of rectangle:
2
Enter width of rectangle:
4
Area: 0.0
Perimeter: 0.0
Press any key to continue . . .
Is it what I have to scan the input (L.setLength...)?
     public static void main(String [] args)
          DecimalFormat onePlace = new DecimalFormat("#0.0");
          Rectangle R = new Rectangle();
          Rectangle L = new Rectangle();
          Rectangle W = new Rectangle();
          Scanner input = new Scanner(System.in);
          System.out.println("Enter length of rectangle: ");
          L.setLength(input.nextDouble());
          System.out.println("\nEnter width of rectangle: ");
          W.setWidth(input.nextDouble());
          System.out.println("\nArea: " + onePlace.format(R.getArea()));
          System.out.println("Perimeter: " + onePlace.format(R.getPerimeter()));
//          System.out.println(R.toString());
}

Non-static method getContentPane() cannot be referenced from a static conte

From this line I'm getting an error
Container bmC = getContentPane();
- non-static method getContentPane() cannot be referenced from a static context
Aprecciate solution,
thx

The reason this is happening is that you can't call non-static methods from a static method. Non-static methods need an instance in order to be called. Static methods are not associated with an instance.

Non-static method close() cannot be referenced from a static context

Friends,
I am having a little help with some static and not static issues.
I created a JMenuBar, it's in the file: SlideViewMenu.java
One of the operations is File->Close and another is File->Exit.
The listener is in the SlideViewMenu.java file. The listener needs to reference two non-static methods within SlideView.java.
Here's some of the code:
SlideViewMenu.java
public class SlideViewMenu {
    public JMenuBar createMenuBar() {
    final Action openAction = new OpenAction();
    Action aboutAction = new AboutAction();
    ActionListener menuListener = new MenuActionListener();
    JMenuBar menuBar = new JMenuBar();
     // All the menu stuff works fine and is taken care of here.
   // Listener for Menu
   class MenuActionListener implements ActionListener {
     public void actionPerformed (ActionEvent actionEvent) {
          String selection = (String)actionEvent.getActionCommand();
         if (selection.equals("Close"))
          SlideViewFrame.close();
         else SlideViewFrame.exit();
}SlideView.java
// Driver class
public class SlideView {
     public static void main(String[] args) {
          ExitableJFrame f = new SlideViewFrame("SlideView");
                // Stuff here, works fine.
// Frame class
class SlideViewFrame extends ExitableJFrame {
        // some things here, work fine.
     private SlideViewMenu menuBar = new SlideViewMenu();
     public SlideViewFrame(String title) {
     // Set title, layout, and background color
     super(title);
     setJMenuBar(menuBar.createMenuBar());
        // Stuff here works fine.
     // Handles doing stuff once the file has been selected
     public void setFileName(File fullFileName, String simpleName) {
        // Stuff here works fine.
     // File->Close. clean up everything.
     public void close() {
          setTitle("SlideView");
          textArea.setText("");
          scrollBar.setVisible(false);
          textArea.setVisible(false);
          statsPanel.setVisible(false);
     // File->Exit.
     public void exit() {
          System.exit(0);
}The error I'm getting is:
SlideViewMenu.java:50: non-static method close() cannot be referenced from a static context
I don't get it?
Thanks for all help.

Making close() and exit() static would not solve the problem because close() requires access to nonstatic member variables/functions.
Fortunately, that is not necessary. The real reason you are having a problem is that you don't have any way in your listener to access the main frame window, which is what the listener trying to control. You made a stab at gaining access by prefixing the function with the class name, but, as the compiler has informed you, that is only valid for static methods. If you think about it, you should see the sense in that, because, what if you had a number of frames and you executed className.close()? Which one would you close? All of them?
Fortunately, there is an easy way out that ties the listener to the frame.
SlideViewMenu.java:public class SlideViewMenu
// Here's where we keep the link to the parent.
private SlideViewFrame parentFrame;
// Here's where we link to the parent.
public JMenuBar createMenuBar(SlideViewFrame linkParentFrame)
    parentFrame = linkParentFrame;
    final Action openAction = new OpenAction();
    Action aboutAction = new AboutAction();
    ActionListener menuListener = new MenuActionListener();
    JMenuBar menuBar = new JMenuBar();
    // All the menu stuff works fine and is taken care of here.
// Listener for Menu --- It is assumed that this is a non-static nested
// class in SlideViewMenu. All SlideViewMenu variables are accessible from
// here. If this is not the case, simply add a similar member variable
// to this class, initialize it with a constructor parameter, and
// pass the SlideViewMenu parentFrame when the listener is
// constructed.
class MenuActionListener implements ActionListener
    public void actionPerformed (ActionEvent actionEvent)
      String selection = (String)actionEvent.getActionCommand();
      // Use parentFrame instead of class name.
      if (selection.equals("Close"))
          parentFrame.close();
        else
          parentFrame.exit();
}SlideView.java// Driver class
public class SlideView
public static void main(String[] args)
    ExitableJFrame f = new SlideViewFrame("SlideView");
    // Stuff here, works fine.
// Frame class
class SlideViewFrame extends ExitableJFrame
// some things here, work fine.
private SlideViewMenu menuBar = new SlideViewMenu();
public SlideViewFrame(String title)
    // Set title, layout, and background color
    super(title);
    //Here's where we set up the link.
    setJMenuBar(menuBar.createMenuBar(this));
// Stuff here works fine.
// Handles doing stuff once the file has been selected
public void setFileName(File fullFileName, String simpleName)
    // Stuff here works fine.
// File->Close. clean up everything.
public void close()
    setTitle("SlideView");
    textArea.setText("");
    scrollBar.setVisible(false);
    textArea.setVisible(false);
    statsPanel.setVisible(false);
// File->Exit.
public void exit()
    System.exit(0);
}

Cannot be referenced from a static context

im trying to link my user interface to the Game class to jump,
i get the error - non static method jump() cannot be referenced from a static context
private void jButton1_actionPerformed(ActionEvent e)
System.out.println("\njButton1_actionPerformed(ActionEvent e) called.");
// code
Game.jump();
any ideas? thanks

ah, it works if i change jump() to static
i was now wondering how to make the user interface
work with this ethod in the Game() class
private void goRoom(Command command)
if(!command.hasSecondWord()) {
// if there is no second word, we don't know where to go...
System.out.println("Go where?");
return;
String direction = command.getSecondWord();
// Try to leave current room.
Room nextRoom = currentRoom.getExit(direction);
if (nextRoom == null)
System.out.println("There is no door!");
else {
currentRoom = nextRoom;
System.out.println(currentRoom.getLongDescription());
i was thinking something like
private void jButton1_actionPerformed(ActionEvent e)
// code
Game.goRoom(Command north);
it doesnt seem to like that though.. :s

"non-static ... cannot be referenced from a static..." BUT they're static!

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