Cannot refer to field class in java

Question

I don't know how to solve below problem. I have got a code like below:

public class MyWindow{
    private Button saveButton;
    private Application saveImplementation;
    void createSaveButton() {
        saveButton.addListener(new Button.ClickListener() {
            @Override
            public void buttonClick(Button.ClickEvent event) {
                this.saveImplementation.save();//Cannot resolve symbol 'saveImplementation'
            }
        });
    }
}

In saveButton.addListener I cannot refer to saveImplementation, which is a field of class MyWindow - can you help me? How can I solve it?

You need MyWindow.this --- you are inside an **inner** class; so "this" alone points to the "wrong" class. — GhostCat, Mar 27 '17 at 09:33
And hint: you are grossly overtagging. This has **nothing** todo with field, lambdas, vaadin whatever. — GhostCat, Mar 27 '17 at 09:34
The error occurs because you have just declare object saveImplementation and not yet instantiate it using new keyword.Just add this line to your 3 line. private Application saveImplementation=new Application(); — bit-shashank, Mar 27 '17 at 09:35
@javafan Wrong. He is right now dealing with a compilation error. That NullPointerException because not initialized comes later, when he would be able to **run** that code. — GhostCat, Mar 27 '17 at 09:36

score 2 · Answer 1 · answered Mar 27 '17 at 09:33

2

this refers to the ClickListener's instance. You need to specify the MyWindow's instance via MyWindow.this.saveImplementation.save();

answered Mar 27 '17 at 09:33

Stefan Warminski

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Cannot refer to field class in java

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