java cannot refer to non-final variable

class, gwt, java

Solution

final TextBox textboxUsername = new TextBox();

and

final TextBox textBoxPassword = new TextBox();

should fix it.

Java requires references to variables from inner classes to be `final` variables (for reasons of concurrency management, I suppose).

Problem

The following code continues to give me: Cannot refer to a non-final variable textBoxPassword inside an inner class defined in a different method Login.java /ChurchWebLogin/src/com/gwt/churchweb/churchweblogin/client line 61 ``` package com.gwt.churchweb.churchweblogin.client; import com.google.gwt.user.client.ui.Composite; import com.google.gwt.user.client.ui.VerticalPanel; import com.google.gwt.user.client.ui.Label; import com.google.gwt.user.client.ui.FlexTable; import com.google.gwt.user.client.ui.TextBox; import com.google.gwt.user.client.ui.HasHorizontalAlignment; import com.google.gwt.user.client.ui.CheckBox; import com.google.gwt.user.client.ui.Button; import com.google.gwt.event.dom.client.ClickHandler; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.user.client.Window; public class Login extends Composite { public Login() { VerticalPanel verticalPanel = new VerticalPanel(); initWidget(verticalPanel); verticalPanel.setSize("329px", "186px"); Label lblNewLabel = new Label("Sign into your account"); lblNewLabel.setStyleName("gwt-Login-SigninLabel"); verticalPanel.add(lblNewLabel); FlexTable flexTable = new FlexTable(); verticalPanel.add(flexTable); flexTable.setWidth("308px"); Label lblNewLabel_1 = new Label("Username:"); lblNewLabel_1.setStyleName("gwt-Label-Login"); flexTable.setWidget(0, 0, lblNewLabel_1); lblNewLabel_1.setWidth("72px"); TextBox textboxUsername = new TextBox(); textboxUsername.setStyleName("gwt-LoginTextBox"); flexTable.setWidget(0, 1, textboxUsername); textboxUsername.setWidth("204px"); Label lblNewLabel_2 = new Label("Password:"); lblNewLabel_2.setStyleName("gwt-Label-Login"); flexTable.setWidget(1, 0, lblNewLabel_2); lblNewLabel_2.setWidth("66px"); TextBox textBoxPassword = new TextBox(); textBoxPassword.setStyleName("gwt-LoginTextBox"); flexTable.setWidget(1, 1, textBoxPassword); textBoxPassword.setWidth("204px"); flexTable.getCellFormatter().setHorizontalAlignment(0, 0, HasHorizontalAlignment.ALIGN_LEFT); flexTable.getCellFormatter().setHorizontalAlignment(1, 0, HasHorizontalAlignment.ALIGN_LEFT); CheckBox chckbxRememberMeOn = new CheckBox("Remember me on this computer"); chckbxRememberMeOn.setStyleName("gwt-Checkbox-Login"); flexTable.setWidget(2, 1, chckbxRememberMeOn); Button btnSignIn = new Button("Sign In"); btnSignIn.addClickHandler(new ClickHandler() { public void onClick(ClickEvent event) { if (textboxUsername.getText().length() == 0 || textBoxPassword.getText().length() == 0) { Window.alert("Username or password is empty."); } } }); btnSignIn.setStyleName("gwt-Login-SigninButton"); flexTable.setWidget(3, 1, btnSignIn); } } ```

Original source