Covid count viewer by county and date in the US. Mostly an experiment to test JavaFX TableView performance.

CovidCases.java

package org.james_d.examples.covidcases;

import com.opencsv.CSVReader;
import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.collections.transformation.FilteredList;
import javafx.concurrent.Task;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.util.Callback;

import java.io.InputStreamReader;
import java.net.URL;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.format.FormatStyle;
import java.util.*;
import java.util.function.Function;

public class CovidCases extends Application {

    private final ObservableList<CovidCaseData> itemsList = FXCollections.observableArrayList();
    private final FilteredList<CovidCaseData> filteredList = new FilteredList<>(itemsList, c ->  true);

    private final MenuButton countyFilter = new MenuButton("Select County");
    private final DatePicker dateFilter = new DatePicker();

    @Override
    public void start(Stage stage)  {

        DataReader reader = new DataReader();

        TableView<CovidCaseData> table = new TableView<>();
        table.setItems(filteredList);

        reader.setOnSucceeded(event -> {
            itemsList.setAll(reader.getValue().data());
            buildMenu(reader.getValue().counties());
        });
        reader.setOnFailed(event -> reader.getException().printStackTrace());
        Thread thread = new Thread(reader);
        thread.setDaemon(true);
        thread.start();

        TableColumn<CovidCaseData, String> idCol = new TableColumn<>("Id");
        idCol.setCellValueFactory(cellData -> new SimpleStringProperty(cellData.getValue().countyUID()));

        // Not used
        TableColumn<CovidCaseData, String> countyCol = new TableColumn<>("County");
        countyCol.setCellValueFactory(cellData -> new SimpleStringProperty(cellData.getValue().county()));

        // Not used
        TableColumn<CovidCaseData, String> stateCol = new TableColumn<>("State");
        stateCol.setCellValueFactory(cellData -> new SimpleStringProperty(cellData.getValue().state()));

        TableColumn<CovidCaseData, String> keyCol = new TableColumn<>("Key");
        keyCol.setCellValueFactory(cellData -> new SimpleStringProperty(cellData.getValue().key()));
        keyCol.setPrefWidth(200);

        TableColumn<CovidCaseData, LocalDate> dateCol = new TableColumn<>("Date");
        dateCol.setCellValueFactory(cellData -> new SimpleObjectProperty<>(cellData.getValue().date()));

        DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM);
        dateCol.setCellFactory(TextTableCell.of(formatter::format));

        TableColumn<CovidCaseData, Number> countCol = new TableColumn<>("Count");
        countCol.setCellValueFactory(cellData -> new SimpleIntegerProperty(cellData.getValue().count()));
        countCol.setCellFactory(TextTableCell.of(count -> String.format("%,d", count.intValue())));

        table.getColumns().add(idCol);
        table.getColumns().add(keyCol);
        table.getColumns().add(dateCol);
        table.getColumns().add(countCol);

        BorderPane root = new BorderPane(table);

        VBox status= new VBox(5);
        Label countyCount = new Label();
        countyCount.textProperty().bind(reader.messageProperty());

        Label itemCount = new Label();
        itemCount.textProperty().bind(Bindings.format("Items in list: %,d", Bindings.size(filteredList)));
        status.getChildren().addAll(countyCount, itemCount);

        root.setBottom(status);

        dateFilter.setOnAction(e -> {
            if (dateFilter.getValue() != null) {
                filteredList.setPredicate(
                        covidCaseData -> Objects.equals(covidCaseData.date(), dateFilter.getValue()));
            }
        });

        Button reset = new Button("Show all");
        reset.setOnAction(e -> {
            dateFilter.setValue(null);
            filteredList.setPredicate(covidCaseData -> true);
        });

        HBox filters = new HBox(10, countyFilter, dateFilter, reset);
        filters.setPadding(new Insets(10));
        root.setTop(filters);

        Scene scene = new Scene(root);
        stage.setScene(scene);
        stage.show();
    }

    private void buildMenu(Map<String, List<String>> counties) {
        counties.keySet().forEach(state -> {
            Menu stateMenu  = new Menu(state);
            counties.get(state).forEach(county -> {
                MenuItem item = new MenuItem(county);
                item.setOnAction(event ->{
                    dateFilter.setValue(null);
                    filteredList.setPredicate(covidCaseData ->
                            covidCaseData.county().equals(county)
                                    && covidCaseData.state().equals(state));
                });
                stateMenu.getItems().add(item);
            });
            countyFilter.getItems().add(stateMenu);
        });
    }

    private static class TextTableCell<S,T> extends TableCell<S,T> {
        private final Function<T, String> format  ;
        TextTableCell(Function<T, String> format) {
            this.format = format ;
        }
        @Override
        protected void updateItem(T item, boolean empty) {
            super.updateItem(item, empty);
            if (empty || item == null) setText("");
            else setText(format.apply(item));
        }

        static <S,T> Callback<TableColumn<S,T>, TableCell<S,T>> of(Function<T, String> format) {
            return tc -> new TextTableCell<>(format);
        }
    }

    private record CovidCaseData(String countyUID, String county, String state,
                         String key, LocalDate date, int count) {  }

    private record LoadResults(List<CovidCaseData> data, Map<String, List<String>> counties) {}

    private static class DataReader extends Task<LoadResults> {

        @Override
        protected LoadResults call() throws Exception {
            String url = "https://raw.githubusercontent.com/CSSEGISandData/COVID-19/master/" +
                    "csse_covid_19_data/csse_covid_19_time_series/time_series_covid19_confirmed_US.csv";
            try (
                    CSVReader parser = new CSVReader(
                            new InputStreamReader(new URL(url).openStream())
                    )
            ) {
                List<CovidCaseData> data = new ArrayList<>();
                String[] header = parser.readNext();
                DateTimeFormatter formatter = DateTimeFormatter.ofPattern("M/d/yy");
                List<LocalDate> dateList = new ArrayList<>();
                for (int i = 11; i < header.length ; i++) {
                    dateList.add(LocalDate.parse(header[i], formatter));
                }
                Map<String, List<String>> counties = new TreeMap<>();
                int count = 0 ;
                for (String[] tokens : parser) {
                    String countyUID = tokens[0];
                    String county = tokens[5];
                    String state = tokens[6];
                    String key = tokens[10];
                    for (int i = 11 ; i < tokens.length ; i++) {
                        data.add(new CovidCaseData(countyUID, county, state, key,
                                dateList.get(i-11), Integer.parseInt(tokens[i])));
                    }
                    counties.computeIfAbsent(state, s -> new ArrayList<>()).add(county);
                    count++;
                    String msg = "Counties loaded: "+count ;
                    updateMessage(msg);
                }
                return new LoadResults(data, counties) ;
            }
        }
    }

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

module-info.java

module org.james_d.examples.covidcases {
    requires javafx.controls;
    requires javafx.fxml;
    requires com.opencsv;

    opens org.james_d.examples.covidcases to javafx.fxml;
    exports org.james_d.examples.covidcases;
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.james_d.examples</groupId>
    <artifactId>covidcases</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>covidcases</name>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <junit.version>5.8.1</junit.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-controls</artifactId>
            <version>17.0.1</version>
        </dependency>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-fxml</artifactId>
            <version>17.0.1</version>
        </dependency>
        <dependency>
            <groupId>com.opencsv</groupId>
            <artifactId>opencsv</artifactId>
            <version>5.5.2</version>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>17</source>
                    <target>17</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.openjfx</groupId>
                <artifactId>javafx-maven-plugin</artifactId>
                <version>0.0.8</version>
                <executions>
                    <execution>
                        <!-- Default configuration for running with: mvn clean javafx:run -->
                        <id>default-cli</id>
                        <configuration>
                            <mainClass>
                                org.james_d.examples.covidcases/org.james_d.examples.covidcases.CovidCases
                            </mainClass>
                            <launcher>app</launcher>
                            <jlinkZipName>app</jlinkZipName>
                            <jlinkImageName>app</jlinkImageName>
                            <noManPages>true</noManPages>
                            <stripDebug>true</stripDebug>
                            <noHeaderFiles>true</noHeaderFiles>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>