我正在尝试在 javafx webview 的帮助下创建一个 Web 浏览器。我正在使用以下代码来创建 Web 浏览器。它在运行程序时给出错误异常
package webviewbrowser;
import com.sun.javaws.Main;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.ListChangeListener;
import javafx.collections.ListChangeListener.Change;
import javafx.concurrent.Worker.State;
import javafx.event.ActionEvent;
import javafx.event.Event;
import javafx.event.EventHandler;
import javafx.geometry.HPos;
import javafx.geometry.Pos;
import javafx.geometry.VPos;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Hyperlink;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Priority;
import javafx.scene.layout.Region;
import javafx.scene.paint.Color;
import javafx.scene.web.PopupFeatures;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebHistory;
import javafx.scene.web.WebHistory.Entry;
import javafx.scene.web.WebView;
import javafx.stage.Stage;
import javafx.util.Callback;
import netscape.javascript.JSObject;
public class WebViewBrowser extends Application {
private Scene scene;
@Override
public void start(Stage stage) {
// create scene
stage.setTitle("Web View");
scene = new Scene(new Browser(), 750, 500, Color.web("#666970"));
stage.setScene(scene);
// apply CSS style
scene.getStylesheets().add("webviewsample/BrowserToolbar.css");
// show stage
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
class Browser extends Region {
private HBox toolBar;
private static String[] imageFiles = new String[]{
"product.png",
"blog.png",
"forum.png",
"partners.png",
"help.png"
};
private static String[] captions = new String[]{
"Products",
"Blogs",
"Forums",
"Partners",
"Help"
};
private static String[] urls = new String[]{
"http://www.oracle.com/products/index.html",
"http://blogs.oracle.com/",
"http://forums.oracle.com/forums/",
"http://www.oracle.com/partners/index.html",
Main.class.getResource("help.html").toExternalForm()
};
final ImageView selectedImage = new ImageView();
final Hyperlink[] hpls = new Hyperlink[captions.length];
final Image[] images = new Image[imageFiles.length];
final WebView browser = new WebView();
final WebEngine webEngine = browser.getEngine();
final Button hideAll = new Button("Hide All");
final Button showAll = new Button("ShowAll");
final WebView smallView = new WebView();
final ComboBox comboBox = new ComboBox();
private boolean needForumButtons = false;
public Browser() {
//apply the styles
getStyleClass().add("browser");
for (int i = 0; i < captions.length; i++) {
// create hyperlinks
Hyperlink hpl = hpls[i] = new Hyperlink(captions[i]);
Image image = images[i] =
new Image(getClass().getResourceAsStream(imageFiles[i]));
hpl.setGraphic(new ImageView(image));
final String url = urls[i];
final boolean addButtons = (hpl.getText().equals("Forums"));
// process event
hpl.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent e) {
needForumButtons = addButtons;
webEngine.load(url);
}
});
}
comboBox.setPrefWidth(60);
// create the toolbar
toolBar = new HBox();
toolBar.setAlignment(Pos.CENTER);
toolBar.getStyleClass().add("browser-toolbar");
toolBar.getChildren().add(comboBox);
toolBar.getChildren().addAll(hpls);
toolBar.getChildren().add(createSpacer());
//set actions for the buttons
hideAll.setOnAction(new EventHandler() {
@Override
public void handle(Event t) {
webEngine.executeScript("hideAll()");
}
});
showAll.setOnAction(new EventHandler() {
@Override
public void handle(Event t) {
webEngine.executeScript("showAll()");
}
});
smallView.setPrefSize(120, 80);
//handle popup windows
webEngine.setCreatePopupHandler(
new Callback<PopupFeatures, WebEngine>() {
@Override public WebEngine call(PopupFeatures config) {
smallView.setFontScale(0.8);
if (!toolBar.getChildren().contains(smallView)) {
toolBar.getChildren().add(smallView);
}
return smallView.getEngine();
}
}
);
//process history
final WebHistory history = webEngine.getHistory();
history.getEntries().addListener(new
ListChangeListener<WebHistory.Entry>(){
@Override
public void onChanged(Change<? extends Entry> c) {
c.next();
for (Entry e : c.getRemoved()) {
comboBox.getItems().remove(e.getUrl());
}
for (Entry e : c.getAddedSubList()) {
comboBox.getItems().add(e.getUrl());
}
}
});
//set the behavior for the history combobox
comboBox.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent ev) {
int offset =
comboBox.getSelectionModel().getSelectedIndex()
- history.getCurrentIndex();
history.go(offset);
}
});
// process page loading
webEngine.getLoadWorker().stateProperty().addListener(
new ChangeListener<State>() {
@Override
public void changed(ObservableValue<? extends State> ov,
State oldState, State newState) {
toolBar.getChildren().removeAll(showAll, hideAll);
if (newState == State.SUCCEEDED) {
JSObject win =
(JSObject) webEngine.executeScript("window");
win.setMember("app", new JavaApp());
if (needForumButtons) {
toolBar.getChildren().addAll(showAll, hideAll);
}
}
}
}
);
// load the home page
webEngine.load("http://www.oracle.com/products/index.html");
//add components
getChildren().add(toolBar);
getChildren().add(browser);
}
// JavaScript interface object
public class JavaApp {
public void exit() {
Platform.exit();
}
}
private Node createSpacer() {
Region spacer = new Region();
HBox.setHgrow(spacer, Priority.ALWAYS);
return spacer;
}
@Override
protected void layoutChildren() {
double w = getWidth();
double h = getHeight();
double tbHeight = toolBar.prefHeight(w);
layoutInArea(browser,0,0,w,h-tbHeight,0,HPos.CENTER,VPos.CENTER);
layoutInArea(toolBar,0,h-tbHeight,w,tbHeight,0,HPos.CENTER,VPos.CENTER);
}
@Override
protected double computePrefWidth(double height) {
return 750;
}
@Override
protected double computePrefHeight(double width) {
return 600;
}
}