local variable is accessed from inner class, needs to be declared final

Question

I am trying to compile this bot from source code. I have however come across a few errors.

It gave me these errors when I tried to compile -

Information:Using javac 1.8.0_101 to compile java sources
Information:java: Errors occurred while compiling module 'BumpBot2'
Information:4/10/2016 10:27 PM - Compilation completed with 18 errors and 0 warnings in 1s 297ms
C:\Users\gabri\Desktop\BumpBot2\src\com\achow101\bumpbot\BumpBot.java
Error:(138, 30) java: local variable urlTextField is accessed from within inner class; needs to be declared final
Error:(139, 35) java: local variable bumpTextTextField is accessed from within inner class; needs to be declared final
Error:(144, 25) java: local variable errorText is accessed from within inner class; needs to be declared final
Error:(145, 25) java: local variable errorText is accessed from within inner class; needs to be declared final
Error:(149, 21) java: local variable errorText is accessed from within inner class; needs to be declared final
Error:(150, 21) java: local variable errorText is accessed from within inner class; needs to be declared final
Error:(172, 21) java: local variable errorText is accessed from within inner class; needs to be declared final
Error:(173, 21) java: local variable errorText is accessed from within inner class; needs to be declared final
Error:(253, 39) java: local variable grid is accessed from within inner class; needs to be declared final
Error:(256, 17) java: local variable urlTextField is accessed from within inner class; needs to be declared final
Error:(257, 17) java: local variable bumpTextTextField is accessed from within inner class; needs to be declared final
Error:(291, 64) java: local variable entry is accessed from within inner class; needs to be declared final
Error:(303, 17) java: local variable grid is accessed from within inner class; needs to be declared final
Error:(303, 43) java: local variable entryUrlLbl is accessed from within inner class; needs to be declared final
Error:(304, 17) java: local variable grid is accessed from within inner class; needs to be declared final
Error:(304, 43) java: local variable entryBumpTextLbl is accessed from within inner class; needs to be declared final
Error:(305, 17) java: local variable grid is accessed from within inner class; needs to be declared final
Error:(305, 43) java: local variable delBtn is accessed from within inner class; needs to be declared final

They are all related to the same file, BumpBot.java. The developer also provides a working .jar file, which I have used and 100% works. When I decompile it, the BumpBot.java output is the exact same thing.

I don't see what's wrong, then. I have tried defining all the variables as final in my code, and it fixes most of my errors, however it leaves the four parse errors regarding the variables regarding entry and grid.

Is my Java installation corrupted?

[hr]

EDIT: This is the code in question. It's long, bear with me here.

public class BumpBot extends Application {

    private int gridHeight = 0;
    private static DoBumps doBumps = new DoBumps();
    private static Thread t = new Thread(doBumps);

    public static void main(String[] args)
    {
        // Start do bumps thread
        t.start();
        launch(args);
    }

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

        // Set GUI Title
        primaryStage.setTitle("Bitcointalk Thread Bump Bot");

        // Create grid for entries
        GridPane grid = new GridPane();
        grid.setAlignment(Pos.TOP_CENTER);
        grid.setHgap(10);
        grid.setVgap(10);
        grid.setPadding(new Insets(25, 25, 25, 25));

        // URL Heading lable
        Label urlLbl = new Label("Bitcointalk URL");
        grid.add(urlLbl, 0, 0);

        // New entry url textfield
        TextField urlTextField = new TextField();
        urlTextField.setPrefWidth(300);
        grid.add(urlTextField, 0, 1);
        gridHeight++;

        // Bump Text heading label
        Label bumpTextLbl = new Label("Bump Text");
        grid.add(bumpTextLbl, 1, 0);

        // New entry bump text textfield
        TextField bumpTextTextField = new TextField();
        bumpTextTextField.setPrefWidth(300);
        grid.add(bumpTextTextField, 1, 1);

        // Button to add entry
        Button addBtn = new Button("Add Bump Entry");
        grid.add(addBtn, 2, 1);

        // Error text
        Text errorText = new Text();
        grid.add(errorText, 1, 2);
        gridHeight += 2;

        // Populate the grid with pre-existing entries
        // Open a database connection
        // (create a new database if it doesn't exist yet):
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("bumps.odb");
        EntityManager em = emf.createEntityManager();

        // Get the next thread to bump
        CriteriaBuilder cb = em.getCriteriaBuilder();
        CriteriaQuery<BumpEntry> qNextBump = cb.createQuery(BumpEntry.class);
        Root<BumpEntry> bump = qNextBump.from(BumpEntry.class);
        qNextBump.select(bump);
        TypedQuery<BumpEntry> query = em.createQuery(qNextBump);
        List<BumpEntry> bumpList = query.getResultList();
        for (BumpEntry entry : bumpList)
        {
            addEntryToGrid(entry, grid);
        }

        // Close the database connection:
        em.close();
        emf.close();

        // Add the entry when clicked
        addBtn.setOnAction(new EventHandler<ActionEvent>() {

            @Override
            public void handle(ActionEvent e) {
                // Get the data from the form
                String url = urlTextField.getText();
                String bumpText = bumpTextTextField.getText();

                // Check the URL
                try {
                    if (!url.substring(0, 40).equals("https://bitcointalk.org/index.php?topic=")) {
                        errorText.setFill(Color.RED);
                        errorText.setText("Incorrect URL");
                        return;
                    }
                } catch (StringIndexOutOfBoundsException e1) {
                    errorText.setFill(Color.RED);
                    errorText.setText("Incorrect URL");
                    return;
                }

                // Trim the URL to just the topic
                String trimUrl = url.substring(0, 40);
                int dotIndex = url.indexOf(".", 40);
                trimUrl += url.substring(40, dotIndex);
                trimUrl += ".0";

                // Escape the bump text
                //escapeInput(bumpText);

                // Open a database connection
                // (create a new database if it doesn't exist yet):
                EntityManagerFactory emf = Persistence.createEntityManagerFactory("bumps.odb");
                EntityManager em = emf.createEntityManager();

                // Check that the thread is not already being bumped
                BumpEntry bEntry = em.find(BumpEntry.class, trimUrl);
                if (bEntry != null)
                {
                    errorText.setFill(Color.RED);
                    errorText.setText("Thread already being bumped");
                    return;
                }

                // Create the entry
                BumpEntry entry = new BumpEntry(trimUrl, bumpText, 0);

                // Check the date of the last post
                try {
                    // Get the first page of the thread
                    Document threadFirstPage = Jsoup.connect(url).get();

                    // Get the navpages elements
                    Element headerNavBar = threadFirstPage.select("div[id=bodyarea] > table[width=100%][cellspacing=0][cellpadding=0][border=0]").first();
                    Elements headerNavPages = headerNavBar.select("tr > td.middletext > a.navPages");

                    // Get the page if there is only one page of posts
                    if (headerNavPages.size() == 0) {
                        headerNavPages = headerNavBar.select("tr > td.middletext > b");
                    }

                    // Get the last page and calculate url number
                    Element lastPage = headerNavPages.last();
                    int pages = Integer.parseInt(lastPage.text());
                    int urlNum = (pages - 1) * 20;

                    // Create the URL for the last page
                    String lastPageUrl = url.substring(0, url.length() - 1);
                    lastPageUrl += urlNum;

                    // Get the last page of the thread
                    Document threadLastPage = Jsoup.connect(lastPageUrl).get();

                    // Get the last post in thread
                    Element postTable = threadLastPage.select("table[cellpadding=0][cellspacing=0][border=0][width=100%].bordercolor > tbody").first();
                    Element firstPost = postTable.select("tr").first();
                    String postClass = firstPost.className();
                    Elements posts = postTable.select("tr." + postClass);
                    Element lastPost = posts.last();

                    // Get the date of last post
                    Element headerAndPost = lastPost.select("td.td_headerandpost").first();
                    Element dateAndSubj = headerAndPost.select("table > tbody > tr > td[valign=middle]").get(1);
                    Element dateElem = dateAndSubj.select("div.smalltext").first();
                    String dateStr = dateElem.text();

                    // Parse date string and get unix timestamp
                    SimpleDateFormat fmt = new SimpleDateFormat("MMMM dd, yyyy, hh:mm:ss a");
                    fmt.setTimeZone(TimeZone.getTimeZone("UTC"));
                    Date date;
                    if (dateStr.contains("Today")) {
                        date = new Date();
                        String currentDateStr = fmt.format(date);
                        dateStr = dateStr.replace("Today at", currentDateStr.substring(0, currentDateStr.lastIndexOf(",") + 1));
                    }
                    date = fmt.parse(dateStr);
                    long unixtime = date.getTime() / 1000;
                    entry.setTime(unixtime);


                } catch (Exception e2) {
                    e2.printStackTrace();
                }

                // add entry to db
                em.getTransaction().begin();
                em.persist(entry);
                em.getTransaction().commit();

                // Notify the bumping thread
                synchronized (doBumps)
                {
                    doBumps.notify();
                }

                // Close the database connection:
                em.close();
                emf.close();

                // Add the entry to display
                addEntryToGrid(entry, grid);

                // Clear textfields
                urlTextField.clear();
                bumpTextTextField.clear();
            }
        });

        Scene scene = new Scene(grid, 1000, 800);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    public void addEntryToGrid(BumpEntry entry, GridPane grid)
    {
        // Thread URL
        TextField entryUrlLbl = new TextField();
        entryUrlLbl.setText(entry.getUrl());
        entryUrlLbl.setEditable(false);

        // Bump Text
        TextField entryBumpTextLbl = new TextField();
        entryBumpTextLbl.setText(entry.getBumpText());
        entryBumpTextLbl.setEditable(false);

        // Delete button
        Button delBtn = new Button("Remove");
        final int row = gridHeight;
        delBtn.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {

                // Open a database connection
                // (create a new database if it doesn't exist yet):
                EntityManagerFactory emf = Persistence.createEntityManagerFactory("bumps.odb");
                EntityManager em = emf.createEntityManager();

                // Get the entry to be deleted
                BumpEntry bumpEntry = em.find(BumpEntry.class, entry.getUrl());

                // Remove entry from db
                em.getTransaction().begin();
                em.remove(bumpEntry);
                em.getTransaction().commit();

                // Close the database connection:
                em.close();
                emf.close();

                // Clear this row's grid
                grid.getChildren().remove(entryUrlLbl);
                grid.getChildren().remove(entryBumpTextLbl);
                grid.getChildren().remove(delBtn);

                // Notify the bumping thread
                synchronized (doBumps)
                {
                    doBumps.notify();
                }
            }
        });

        // Add to display
        grid.add(entryUrlLbl, 0, gridHeight);
        grid.add(entryBumpTextLbl, 1, gridHeight);
        grid.add(delBtn, 2, gridHeight);
        gridHeight++;
    }

    @Override
    public void stop()
    {
        System.exit(0);
    }

    public String escapeInput(String input) {
        String[] characters = {"\"", "\\", "{", "}"};
        StringBuilder sb = new StringBuilder();
        sb.append("\"");
        String line = input;
        for (String test : characters) {
            line = line.replace(test, "\\" + test);
        }
        sb.append("\"");
        return sb.toString();
    }
}

Answer 1

As Suresh Atta says in here Difference between final and effectively final

... starting in Java SE 8, a local class can access local variables and parameters of the enclosing block that are final or effectively final. A variable or parameter whose value is never changed after it is initialized is effectively final.

If there's no dependecy to Java8 you can try to compile it with Java7.