Why am I getting a "cannot find symbol" error in Java?

Question

@Override
public Component getTableCellRendererComponent(
        JTable table, Object value, boolean isSelected,
        boolean hasFocus, int row, int col) {

    // *** here  *** 
    Component c = super.getTableCellRendererComponent(table, value, isSelected, 
               hasFocus, row, col); 

    // Formatting here
    return c;
}

I'm getting an error in the indicated line. It says "cannot find symbol" but I can't realize what the real problem is.

Updated

@martinusadyh

I'm afraid the class is too big so it doesn't allow me to paste it here.

@ Hovercraft Full Of Eels

here's the error in Netbeans
https://i.stack.imgur.com/R4fv3.jpg

@Henery

It's not my class. I'm only implementing an interface method.

Please show the actual text of the error message in your post above. Does it say more than "cannot find symbol"? Every bit of information is essential. — Hovercraft Full Of Eels, Nov 05 '11 at 14:44
Did you make sure that your super class contain the exact method getTableCellRendererComponent with the same signature? — Bhavesh, Nov 05 '11 at 14:51
@Maxi Dee: can you paste your full source code ? I mean, we need to know which class you implemented or extend. — martinusadyh, Nov 05 '11 at 14:53
@martinusadyh I'm afraid the class it's too big so it doesnt allow me to paste it here. — Maxi Dee, Nov 05 '11 at 15:14
PLEASE! Do me (and yourself) a favour and put the font of NetBeans to something **Monospaced**... — Martijn Courteaux, Nov 05 '11 at 15:14
In which class this method getTableCellRendererComponent() is implemented? or at least say which class you are extending if such is a case? — Bhavesh, Nov 05 '11 at 15:14
@ Hovercraft Full Of Eels here's the error in Netbeans h t t p : / / i. stack.i mgur.com/R4fv3.jpg — Maxi Dee, Nov 05 '11 at 15:16
@martinusadyh done, here's the code h t t p://pastebin.com/m7QnkUMC its too big to paste it here. — Maxi Dee, Nov 05 '11 at 15:21
@MaxiDee: that's why you shouldn't try to have a class do too much. Your class extends JPanel and implements TableCellRenderer, but JPanel doesn't have the super method. Perhaps you want your class to extend DefaultTableCellRenderer. — Hovercraft Full Of Eels, Nov 05 '11 at 15:37
@MaxiDee you get error because `super` in your method calling JPanel class, and JPanel don't have method `getTableCellRendererComponent()`. If you want to do some custom rendering to your JTable, why you do not implemented in your method in this class ? Why you must call `super` ??? — martinusadyh, Nov 05 '11 at 15:38

A.H. · Answer 1 · 2011-11-05T15:25:25.880

3

It's not mine that class, i'm only implementing an interface's method.

Then your parent class super is Object and has no method getTableCellRendererComponent. You either have to extend a suitable class or get along without calling non-existing methods.

edited Nov 05 '11 at 15:25

answered Nov 05 '11 at 15:16

A.H.

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Makes sense -- but then why wouldn't there be an error at the @Override annotation? The `getTableCellRendererComponent` method certainly doesn't override a method of Object. – Hovercraft Full Of Eels Nov 05 '11 at 15:19
1

If he is using Java6 @Hovercraft, the `Override` could be for the interface method so there is not a super method with the same name. – Gray Nov 05 '11 at 15:30
@A.H.: Aha and exactly! That's what was tripping me up. Great thoughts and 1+. – Hovercraft Full Of Eels Nov 05 '11 at 15:35
@HovercraftFullOfEels, i'm using java 7 – Maxi Dee Nov 05 '11 at 15:50
@MaxiDee: what does using Java 7 have to do with the price of tea in China? – Hovercraft Full Of Eels Nov 05 '11 at 15:53
@HovercraftFullOfEels i know i know – Maxi Dee Nov 05 '11 at 16:00
@Gray im using java 7, i dont think that this is important – Maxi Dee Nov 05 '11 at 16:01
@gray when I used the code in answer 2, I realized that I was calling a super method, when the class wasn't inheriting nothing. – Maxi Dee Nov 05 '11 at 18:09

Martijn Courteaux · Answer 2 · 2011-11-05T15:41:41.200

2

You have to extends DefaultTableCellRenderer instead of implements TableCellRenderer.

Note: DefaultTableCellRenderer its method getTableCellRendererComponent returns this. This means that it's enough to call the super.getTableCellRendererComponent(); without assigning it to a local variable. Because the local variable equals this. Maybe my explanation is too difficult: example.

public class MyTableCellRenderer extends DefaultTableCellRenderer
{

    @Override
    public Component getTableCellRendererComponent(
            JTable table, Object value, boolean isSelected,
            boolean hasFocus, int row, int col) {

        super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, col); 

        // Formatting here
        setIcon(myCustomIcon);
        setText(myCustomText);

        return this;
    }

}

edited Nov 05 '11 at 15:41

answered Nov 05 '11 at 15:36

Martijn Courteaux

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i cant extend DefaultTableCellRenderer because im already extending JPanel to show the table! – Maxi Dee Nov 05 '11 at 15:52
1

@MaxiDee: then it's obvious you can't call the super method. Solution: don't try to do this. – Hovercraft Full Of Eels Nov 05 '11 at 16:11
@HovercraftFullOfEels to sum up, then, I'll have to try painting the cells using other tecniques.. thx!! – Maxi Dee Nov 05 '11 at 16:17
@MaxiDee: No, you have to create a **new** class. (Which means a new `.java` file). Then use an instance of that class as cell renderer for your table. – Martijn Courteaux Nov 05 '11 at 16:31
@MartijnCourteaux i'll try creating a new class, see how can I make it work, then I tell you. Thanks for the tip. – Maxi Dee Nov 05 '11 at 18:00
@MartijnCourteaux sorry for me asking so much, but where i should instance the class extending DefaultTableCellRenderer? because i try to call the getTableCellRendererComponent method but it wont work – Maxi Dee Nov 05 '11 at 18:23
`myTable.setDefaultRenderer(Object.class, new MyTableCellRenderer());` – Martijn Courteaux Nov 05 '11 at 20:07

Why am I getting a "cannot find symbol" error in Java?

2 Answers2