Swing UI to delete attachments from confluence pages in batches

RemoveConfluenceAttachments.java

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.itextpdf.xmp.impl.Base64;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;

import javax.net.ssl.HttpsURLConnection;
import javax.swing.*;
import javax.xml.ws.Holder;
import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;

public class RemoveConfluenceAttachments {
    
    private static final String CONFLUENCE_BASE = "https://YOUR_DOMAIN_HERE/";

    public static void main(String[] args) throws IOException {

        // Set up our main UI
        JFrame mainFrame = new JFrame("Remove attachments");
        mainFrame.setSize(400, 400);
        mainFrame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent windowEvent){
                System.exit(0);
            }
        });

        JPanel header = new JPanel();
        JTextField input = new JTextField(args.length > 1 ? args[1] : "");
        header.add(input, BorderLayout.WEST);
        JButton load = new JButton("Load");
        header.add(load, BorderLayout.EAST);
        mainFrame.add(header, BorderLayout.NORTH);


        JPanel comp = new JPanel();
        JScrollPane scrollPane = new JScrollPane(comp,
                ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
                ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
        mainFrame.add(scrollPane, BorderLayout.CENTER);

        Map<JCheckBox, JsonNode> nodes = new LinkedHashMap<>();

        Holder<JCheckBox> checkAll = new Holder<>();
        initUI(args[0], input.getText(), comp, scrollPane, nodes, checkAll);

        load.addActionListener((e) -> new SwingWorker<Void, Void>() {
            @Override
            protected Void doInBackground() {
                try {
                    initUI(args[0], input.getText(), comp, scrollPane, nodes, checkAll);
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
                return null;
            }
        }.execute());

        JButton buttonRemove = new JButton("Remove selected");
        buttonRemove.addActionListener(e -> new SwingWorker<Void, Void>() {
            @Override
            protected Void doInBackground() {
                for (Iterator<JCheckBox> iterator = nodes.keySet().iterator(); iterator.hasNext(); ) {
                    JCheckBox x = iterator.next();
                    if (x.isSelected()) {
                        try {
                            String id = nodes.get(x).get("id").asText();
                            if (StringUtils.isEmpty(id)) {
                                System.err.println("empty");
                                continue;
                            }
                            if (delete(CONFLUENCE_BASE + "rest/api/content/" + nodes.get(x).get("id").asText(), args[0])) {
                                iterator.remove();
                                nodes.remove(x);
                                comp.remove(x);
                            } else {
                                System.err.println("failed");
                            }
                        } catch (IOException ex) {
                            System.err.println("failed: " + ex.getMessage());
                        }
                    }
                    scrollPane.revalidate();
                }
                checkAll.value.setSelected(nodes.keySet().stream().allMatch(JCheckBox::isSelected));
                comp.updateUI();
                return null;
            }
        }.execute());
        mainFrame.add(buttonRemove, BorderLayout.SOUTH);

        mainFrame.setVisible(true);
    }

    private static void initUI(String password, String id, JPanel comp, JScrollPane scrollPane, Map<JCheckBox, JsonNode> nodes, Holder<JCheckBox> checkAll_) throws IOException {
        nodes.clear();
        comp.removeAll();

        if (StringUtils.isEmpty(id)) {
            return;
        }
        JsonNode rootNode = getAsJson(CONFLUENCE_BASE + "rest/api/content/" + id + "/child/attachment", password);
        JsonNode results = rootNode.get("results");
        comp.setLayout(new GridLayout(results.size() + 2, 1));

        JCheckBox checkAll = new JCheckBox("Check all");
        checkAll.addChangeListener(e -> nodes.forEach((k, v) -> k.setSelected(checkAll.isSelected())));
        comp.add(checkAll);

        for (JsonNode i : results) {
            JCheckBox checkbox = new JCheckBox(i.get("title").asText());
            nodes.put(checkbox, i);
            comp.add(checkbox);
        }

        scrollPane.revalidate();

        checkAll_.value = checkAll;
    }

    private static JsonNode getAsJson(String u, String usernameAndPassword) throws IOException {
        URL url = new URL(u);
        HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
        connection.setRequestProperty("Authorization", "Basic " + Base64.encode(usernameAndPassword));
        ObjectMapper mapper = new ObjectMapper();
        JsonNode rootNode = mapper.readTree(connection.getInputStream());
        connection.disconnect();
        return rootNode;
    }

    private static boolean delete(String u, String usernameAndPassword) throws IOException {
        URL url = new URL(u);
        HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
        connection.setRequestMethod("DELETE");
        connection.setRequestProperty("Authorization", "Basic " + Base64.encode(usernameAndPassword));
        boolean result = connection.getResponseCode() >= HttpURLConnection.HTTP_OK && connection.getResponseCode() <= HttpURLConnection.HTTP_NO_CONTENT;
        if (!result) {
            System.err.println(connection.getResponseCode());
            if (connection.getErrorStream() != null) {
                System.err.println(IOUtils.toString(connection.getErrorStream(), connection.getContentEncoding()));
            }
            if (connection.getInputStream() != null) {
                System.err.println(IOUtils.toString(connection.getInputStream(), connection.getContentEncoding()));
            }
        }
        connection.disconnect();
        return result;
    }

}