我正在尝试在另一个程序中使用 Java 组件。该程序是运行在 Tomcat 上的 Web 应用程序，我的组件使用 Swing 打开 Web 浏览器。提示用户导航到特定页面，并使用 JFrame 上的控件，页面以 HTML 格式保存在本地。这个本地保存的文件稍后将用于进一步阐述。问题是，当从 Eclipse 执行时，我的代码可以正常工作。但是，当我使用在 Tomcat 上运行的应用程序中的组件时，它运行不正确。出现该窗口，导航正在工作，并且可以毫无问题地检索数据。问题是主应用程序（在 Tomcat 上运行的应用程序）必须在组件（Java）完成工作后恢复执行。显然，出现了问题，因为 Web 应用程序只是挂起，并且永远不会继续。
在我的组件中，我使用了两个类：Browser 和 Helper。浏览器基于 DJ NativeSwing 库并包含初始化和显示简单 Web 浏览器的逻辑。Helper 类为我提供了一个“前端”方法，它允许我在自己的线程中执行浏览器。我使用的是 SwingUtilities.invokeAndWait 而不是 invokeLater，因为我不太清楚如何使用 wait() 和 notify()。我尝试过，但失败了。
总结一下代码，它看起来像这样：
import javax.swing.SwingUtilities;
import chrriis.dj.nativeswing.swtimpl.NativeInterface;
public class Helper {
public String Browse() {
Browser vb = new Browser();
try {
Browser.log("This is Helper, now initiating.");
NativeInterface.open();
Thread th = new Thread(vb);
Browser.log("Helper is invoking thread...");
SwingUtilities.invokeAndWait(th);
NativeInterface.runEventPump();
Browser.log("Thread exited! Back to Helper!");
System.out.println(vb.getData());
Browser.log("Returning data to caller: \n" + vb.getData());
return vb.getData();
}catch (Exception ex) {
ex.printStackTrace();
Browser.log("MainFail: " + ex.getMessage());
return ex.getMessage();
}
}
和浏览器类：
import java.awt.BorderLayout;
import java.awt.Insets;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowEvent;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import chrriis.dj.nativeswing.NativeSwing;
import chrriis.dj.nativeswing.swtimpl.NativeInterface;
import chrriis.dj.nativeswing.swtimpl.components.JWebBrowser;
public class Browser extends JFrame implements ActionListener, Runnable {
private static final long serialVersionUID = 1L;
private JButton btn;
private JWebBrowser webBrowser;
private JPanel panel;
private String data = "";
public static void log(String s) {
try {
BufferedWriter ostr = new BufferedWriter(new FileWriter("F:/java_out.log", true));
Date dt = new Date();
SimpleDateFormat formatter = new SimpleDateFormat("hh:mm:ss");
String str = formatter.format(dt) + "\t -> " + s + "\n";
ostr.write(str);
ostr.close();
} catch(Exception ex) {
System.out.println("Logger: " + ex.getMessage());
}
}
public Browser() {
Browser.log("Initializing...");
NativeSwing.initialize();
NativeInterface.open();
panel = new JPanel();
btn = new JButton();
btn.setText("Save Page");
btn.addActionListener(this);
btn.setMargin(new Insets(5, 5, 5, 5));
VisureBrowser.log("Button is ready!");
JPanel webBrowserPanel = new JPanel(new BorderLayout());
webBrowserPanel.setBorder(BorderFactory.createTitledBorder("Navigate and save"));
webBrowser = new JWebBrowser();
webBrowser.setButtonBarVisible(true);
webBrowser.setMenuBarVisible(false);
webBrowser.setLocationBarVisible(true);
VisureBrowser.log("Panel is ready!");
this.setTitle("Simple Browser");
this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
this.setSize(800, 600);
this.setLayout(new BorderLayout());
this.setLocationByPlatform(true);
this.setLocationRelativeTo(null);
VisureBrowser.log("Frame is ready!");
this.add(btn, BorderLayout.BEFORE_FIRST_LINE);
btn.setVisible(true);
webBrowserPanel.add(webBrowser, BorderLayout.CENTER);
webBrowser.setVisible(true);
this.add(webBrowserPanel, BorderLayout.CENTER);
panel.setVisible(true);
this.setVisible(true);
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
SwingUtilities.updateComponentTreeUI(this);
} catch (Exception e) {
Browser.log("Constructor: " + e.getMessage());
Browser.log(e.getStackTrace().toString());
e.printStackTrace();
}
Browser.log("Look and Feel ready as well! Off to work...");
}
public String getData() {
return this.data;
}
public void close() {
WindowEvent wev = new WindowEvent(this, WindowEvent.WINDOW_CLOSING);
Toolkit.getDefaultToolkit().getSystemEventQueue().postEvent(wev);
}
public void run() {
Browser.log("Navigating to the index page...");
webBrowser.navigate("http://www.google.com/");
Browser.log("Navigation successful!");
}
@Override
public void actionPerformed(ActionEvent e) {
Browser.log("An action has been performed!");
Object src = e.getSource();
if (src.equals(btn)) {
try {
Browser.log("Getting data...");
this.data = webBrowser.getHTMLContent();
Browser.log("Closing...");
this.close();
} catch( Exception ex) {
Browser.log("ClickFail: " + ex.getMessage());
Browser.log(ex.getStackTrace().toString());
}
}
}
}
我得到的输出是来自 Eclipse：
12:28:54 -> Initializing...
12:28:55 -> Button is ready!
12:28:55 -> Panel is ready!
12:28:55 -> Frame is ready!
12:28:56 -> Look and Feel ready as well! Off to work...
12:28:56 -> This is Helper, now initiating.
12:28:56 -> Helper is invoking thread...
12:28:56 -> Navigating to the index page...
12:28:56 -> Navigation successful!
12:29:04 -> An action has been performed!
12:29:04 -> Getting data...
12:29:04 -> Closing...
12:29:06 -> Thread exited! Back to Helper!
12:29:06 -> Returning data to caller:
.....here comes all the data.....
我在Tomcat中执行时得到的数据如下：
12:28:54 -> Initializing...
12:28:55 -> Button is ready!
12:28:55 -> Panel is ready!
12:28:55 -> Frame is ready!
12:28:56 -> Look and Feel ready as well! Off to work...
12:28:56 -> This is Helper, now initiating.
12:28:56 -> Helper is invoking thread...
12:28:56 -> Navigating to the index page...
12:28:56 -> Navigation successful!
12:29:04 -> An action has been performed!
12:29:04 -> Getting data...
12:29:04 -> Closing...
是的，我使用了相同的行，但输出是这样的，它只到结束行。我没想到的是关闭窗口和恢复主要活动之间的延迟：每次运行大约 2-3 秒。我想象它与辅助（GUI）线程没有正确退出有关，但我不知道如何继续。
任何帮助将不胜感激！:)