(JAVA) Event handlers, Anonymous inner classes, lambda expressions

with-anonymous-inner-class.java

import java.sql.Connection;
import javafx.application.Application;
import javafx.stage.Stage;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
public class UI extends Application {

	private static Connection con = null;
	private static Button btnConnect
	, btnGetRows;

	public static void main(String[] args) {
		launch(args);

	}

	@Override
	public void start(Stage primaryStage) throws Exception {

		primaryStage.setTitle("Thought log");
		btnConnect = new Button();
		btnConnect.setText("Connect");
		btnConnect.setOnAction(new EventHandler<ActionEvent>() {
			@Override
			public void handle(ActionEvent event) {
				con = RemoteConnection.connect();
			}
		});
		btnGetRows = new Button();
		btnGetRows.setText("Get items");
		btnConnect.setOnAction(new EventHandler<ActionEvent>() {
			@Override
			public void handle(ActionEvent event) {
				PostgreSQLDatabase.getRows(con, "schemaName", "tableName");
			}
		});
		StackPane layout = new StackPane();
		layout.getChildren().add(btnConnect);
		//        root.getChildren().add(btnGetRows);
		Scene scene = new Scene(layout, 400, 400);
		primaryStage.setScene(scene);
		primaryStage.show();
	}
}

with-interface.java

import java.sql.Connection;
import javafx.application.Application;
import javafx.stage.Stage;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
public class UI extends Application implements EventHandler<ActionEvent> {

	private static Connection con = null;
	private static Button btnConnect
	, btnGetRows;

	public static void main(String[] args) {
		launch(args);
	}

	@Override
	public void start(Stage primaryStage) throws Exception {

		primaryStage.setTitle("Thought log");
		btnConnect = new Button();
		btnConnect.setText("Connect");
		btnConnect.setOnAction(this);
		btnGetRows = new Button();
		btnGetRows.setText("Get items");
    btnGetRows.setOnAction(this);
		StackPane layout = new StackPane();
		layout.getChildren().add(btnConnect);
		Scene scene = new Scene(layout, 400, 400);
		primaryStage.setScene(scene);
		primaryStage.show();
	}
	/**
	 * Handle user triggered events
	 */
	@Override
	public void handle(ActionEvent event){
		Object reference = event.getSource();
		if(reference == btnConnect)
			con = RemoteConnection.connect();
		if (reference == btnGetRows)
			PostgreSQLDatabase.getRows(con, "schemaName", "tableName");
	}


}

with-java-lambda.java

import java.sql.Connection;
import javafx.application.Application;
import javafx.stage.Stage;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
public class UI extends Application {

	private static Connection con = null;
	private static Button btnConnect
	, btnGetRows;

	public static void main(String[] args) {
		launch(args);

	}

	@Override
	public void start(Stage primaryStage) throws Exception {

		primaryStage.setTitle("Thought log");
		btnConnect = new Button();
		btnConnect.setText("Connect");
		btnConnect.setOnAction(e -> con = RemoteConnection.connect());
		btnGetRows = new Button();
		btnGetRows.setText("Get items");
		btnConnect.setOnAction(e -> PostgreSQLDatabase.getRows(con, "schemaName", "tableName"));
		StackPane layout = new StackPane();
		layout.getChildren().add(btnConnect);
		//        root.getChildren().add(btnGetRows);
		Scene scene = new Scene(layout, 400, 400);
		primaryStage.setScene(scene);
		primaryStage.show();
	}
}