Part three

src/webcrawler/ApplicationRunner.java

@@ -1,7 +1,11 @@
 package webcrawler;
 
+import webcrawler.crawl.HtmlPageParser;
+
 public class ApplicationRunner {
-    public static void main(String[] args) {
-        new WebCrawler();
-    }
+
+  public static void main(String[] args) {
+    HtmlPageParser pageParser = new HtmlPageParser();
+    new WebCrawlerWindow(pageParser);
+  }
 }

src/webcrawler/WebCrawlerWindow.java

@@ -0,0 +1,105 @@
+package webcrawler;
+
+import java.awt.ComponentOrientation;
+import java.awt.Dimension;
+import java.awt.FlowLayout;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.URL;
+import javax.swing.BorderFactory;
+import javax.swing.BoxLayout;
+import javax.swing.JButton;
+import javax.swing.JFrame;
+import javax.swing.JLabel;
+import javax.swing.JPanel;
+import javax.swing.JScrollPane;
+import javax.swing.JTextArea;
+import javax.swing.JTextField;
+import javax.swing.SwingUtilities;
+import webcrawler.crawl.Html;
+import webcrawler.crawl.HtmlPageParser;
+
+public class WebCrawlerWindow extends JFrame {
+
+  public static final String LINE_SEPARATOR = System.getProperty("line.separator");
+  private final JTextArea textArea;
+  private final JTextField location;
+  private final JButton goButton;
+  private final JLabel titleLabelInfo;
+  private final JLabel titleLabel;
+
+  private final HtmlPageParser pageParser;
+
+  public WebCrawlerWindow(HtmlPageParser pageParser) {
+    this.pageParser = pageParser;
+    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+    setSize(600, 600);
+
+    this.location = new JTextField("http://example.com");
+    this.goButton = new JButton("Get text!");
+    this.textArea = new JTextArea();
+    this.titleLabelInfo = new JLabel("Title: ");
+    this.titleLabel = new JLabel();
+    initLayout();
+    initActions();
+    setVisible(true);
+  }
+
+  private void initActions() {
+    goButton.addActionListener(e ->
+        SwingUtilities.invokeLater(() -> {
+          String url = location.getText();
+          try (
+              InputStream inputStream = new URL(url).openStream();
+              BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))
+          ) {
+            final StringBuilder stringBuilder = new StringBuilder();
+            String nextLine;
+            while ((nextLine = reader.readLine()) != null) {
+              stringBuilder.append(nextLine);
+              stringBuilder.append(LINE_SEPARATOR);
+            }
+            final String siteText = stringBuilder.toString();
+            Html html = pageParser.parse(siteText);
+            textArea.setText(siteText);
+            titleLabel.setText(html.getTitle());
+          } catch (IOException e1) {
+            textArea.setText("No content");
+          }
+        }));
+  }
+
+  private void initLayout() {
+    var rootPanel = getContentPane();
+
+    var locationPanel = new JPanel();
+    locationPanel.setLayout(new BoxLayout(locationPanel, BoxLayout.LINE_AXIS));
+    locationPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
+    locationPanel.add(location);
+    locationPanel.add(goButton);
+
+    var titlePanel = new JPanel();
+    titlePanel.setLayout(new FlowLayout(FlowLayout.LEFT));
+    titlePanel.setComponentOrientation(ComponentOrientation.LEFT_TO_RIGHT);
+    titlePanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
+    titlePanel.add(titleLabelInfo);
+    titlePanel.add(titleLabel);
+
+    var scrollPane = new JScrollPane(textArea);
+    scrollPane.setPreferredSize(new Dimension(400, 400));
+
+    var areaPanel = new JPanel();
+    areaPanel.setLayout(new BoxLayout(areaPanel, BoxLayout.PAGE_AXIS));
+    areaPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
+    areaPanel.add(scrollPane);
+
+    rootPanel.setLayout(new BoxLayout(rootPanel, BoxLayout.PAGE_AXIS));
+    rootPanel.add(locationPanel);
+    rootPanel.add(titlePanel);
+    rootPanel.add(areaPanel);
+
+    pack();
+  }
+}

src/webcrawler/crawl/Html.java

@@ -0,0 +1,14 @@
+package webcrawler.crawl;
+
+public class Html {
+
+  private String title;
+
+  public Html(String title) {
+    this.title = title;
+  }
+
+  public String getTitle() {
+    return title;
+  }
+}

src/webcrawler/crawl/HtmlPageParser.java

@@ -0,0 +1,19 @@
+package webcrawler.crawl;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class HtmlPageParser {
+
+  private Pattern titlePattern;
+
+  public HtmlPageParser() {
+    this.titlePattern = Pattern.compile("<title>(.*)</title>");
+  }
+
+  public Html parse(String siteText) {
+    Matcher matcher = titlePattern.matcher(siteText);
+    boolean found = matcher.find();
+    return found ? new Html(matcher.group(1)) : new Html("No title");
+  }
+}