我为 GUI 更新系统创建了一个 JAR，该系统在其内部下载一个可执行文件并执行它。每当我运行原始副本时，这对我来说都是完美的。然而，当从互联网下载时，GUI 就崩溃了。标题字体恢复为原始字体，下载按钮激活预定的对话框，但其中不执行任何下载文件的操作。请记住，我的 setup.jar 的原始副本可以工作，但下载的版本没有任何作用。
可以找到该 JAR here ，但专门用于直接下载，您可能会找到它 here 。
以下是我的 JAVA 文件的内容以及 JAR 层次结构的图片:
public class UpdateMechanism extends JFrame
implements ActionListener {
protected static JButton aroundTheLake;
protected static JFrame frame;
private static JButton aroundTheRiver() {
aroundTheLake = new JButton("DOWNLOAD & INSTALL!");
aroundTheLake.setVerticalTextPosition(AbstractButton.CENTER);
aroundTheLake.setHorizontalTextPosition(AbstractButton.LEADING); //aka LEFT, for left-to-right locales
aroundTheLake.addActionListener(new UpdateMechanism());
aroundTheLake.setMnemonic(KeyEvent.VK_D);
aroundTheLake.setActionCommand("aroundthelake");
return aroundTheLake;
}
private static String readURL(String targetURL) {
String returnish = "";
try {
URL tempURL = new URL(targetURL);
Scanner s = new Scanner(tempURL.openStream());
while (s.hasNextLine()) {
returnish = returnish+s.nextLine();
}
} catch (IOException e) {
System.out.println(e);
}
return returnish;
}
private static String readFile(String targetFile) {
String returnString = "";
try {
File tempFile = new File(targetFile);
Scanner s = new Scanner(tempFile);
while (s.hasNextLine()) {
returnString = returnString + s.nextLine();
}
} catch(IOException e) {
// !
System.out.println(e);
}
return returnString;
}
public void actionPerformed(ActionEvent e) {
if ("aroundthelake".equals(e.getActionCommand())) {
JOptionPane.showMessageDialog(frame,
"Please wait, this may take a while depending on your connection...");
new Thread() {
public void run() {
URL url;
URLConnection con;
DataInputStream dis;
FileOutputStream fos;
byte[] fileData;
try {
url = new URL("http://hivelocity.dl.sourceforge.net/project/theneverhood/setup.exe");
con = url.openConnection();
dis = new DataInputStream(con.getInputStream());
fileData = new byte[con.getContentLength()];
for (int x = 0; x < fileData.length; x++) {
fileData[x] = dis.readByte();
}
dis.close();
fos = new FileOutputStream(new File("executable/setup.exe"));
fos.write(fileData);
fos.close();
Runtime.getRuntime().exec("executable/setup.exe", null, new File("executable/"));
}
catch(MalformedURLException m) {
System.out.println(m);
}
catch(IOException io) {
System.out.println(io);
}
}
}.start();
} else {
// man
}
}
private static void showGUI() {
frame = new JFrame("The Neverhood Restoration Project");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(new Dimension(1024, 600));
frame.setExtendedState(frame.MAXIMIZED_BOTH);
frame.getContentPane().setBackground(new Color(0xA64343));
File fileCheck = new File("C:/Program Files (x86)");
String returnString = null;
String rootDirectory = null;
if (fileCheck.exists()) {
rootDirectory = "C:/Program Files (x86)/DreamWorks Interactive";
String checkFile = rootDirectory+"/Neverhood/version.txt";
File tempFile = new File(checkFile);
if (tempFile.exists()) {
returnString = readFile(checkFile);
} else {
returnString = "It appears you do not have the Neverhood Restoration Project installed, or you are using an earlier version.";
}
} else {
rootDirectory = "C:/Program Files/DreamWorks Interactive";
String checkFile = rootDirectory+"/Neverhood/version.txt";
File tempFile = new File(checkFile);
if (tempFile.exists()) {
returnString = readFile(checkFile);
} else {
returnString = "It appears you do not have the Neverhood Restoration Project installed, or you are using an earlier version.";
}
}
if (returnString.equals(readURL("http://theneverhood.sourceforge.net/version.txt"))) {
returnString = "You are updated to the recent version!";
} else {
returnString = "It appears you're not updated.";
}
JLabel headerLabel = new JLabel("The Neverhood Restoration Project");
headerLabel.setHorizontalAlignment(JLabel.CENTER);
JPanel heapPanel = new JPanel();
heapPanel.setLayout(new BoxLayout(heapPanel, BoxLayout.PAGE_AXIS));
heapPanel.setPreferredSize(new Dimension(500, heapPanel.getPreferredSize().height));
JTextArea heapLabel = new JTextArea(50, 50);
heapLabel.setLineWrap(true);
heapLabel.setWrapStyleWord(true);
heapLabel.setEditable(false);
heapLabel.setBorder(BorderFactory.createEmptyBorder(10, 20, 10, 20));
heapLabel.setFont(new Font("Serif", Font.PLAIN, 14));
heapLabel.append("Current version: "+readURL("http://theneverhood.sourceforge.net/prettyversion.txt")+".\nInstalled version: "+readFile(rootDirectory+"/Neverhood/prettyversion.txt")+".\n"+returnString+"\n" +
"You can read the full version of the document to the left at http://theneverhood.sourceforge.net."
+ "\nHaven't installed yet? Below is the download button. Just click to save setup.exe in and enjoy!");
heapPanel.add(heapLabel);
if (returnString == "It appears you're not updated.") {
heapPanel.add(aroundTheRiver());
}
try {
Font sFont = Font.createFont(Font.TRUETYPE_FONT, new File("DUGFB___.TTF"));
sFont = sFont.deriveFont(Font.PLAIN, 48);
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
ge.registerFont(sFont);
headerLabel.setFont(sFont);
} catch (FontFormatException | IOException e) {
System.out.println(e);
}
BufferedImage icoImage = null;
try {
icoImage = ImageIO.read(
frame.getClass().getResource("/nhood.bmp"));
} catch (IOException e) {
System.out.println(e);
}
frame.setIconImage(icoImage);
JEditorPane updateLog = new JEditorPane();
JScrollPane scrollPane = new JScrollPane(updateLog);
updateLog.setEditable(false);
try {
updateLog.setPage("http://theneverhood.sourceforge.net/");
} catch (IOException e) {
updateLog.setContentType("text/html");
updateLog.setText("<html>The application could not load the webpage.</html>");
}
frame.add(headerLabel, BorderLayout.NORTH);
frame.add(scrollPane);
frame.add(heapPanel, BorderLayout.EAST);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
showGUI();
}
});
}
}
这张图片是从提供的链接下载的。
最佳答案
代码中有很多小错误:
new Thread() {
public void run() {
URL url;
URLConnection con;
DataInputStream dis;
FileOutputStream fos;
byte[] fileData;
try {
url = new URL("http://hivelocity.dl.sourceforge.net/project/theneverhood/setup.exe");
con = url.openConnection();
dis = new DataInputStream(con.getInputStream());
fileData = new byte[con.getContentLength()];
for (int x = 0; x < fileData.length; x++) {
fileData[x] = dis.readByte();
}
dis.close();
File f = new File("executable");
if(!f.isDirectory())
f.mkdir();
fos = new FileOutputStream(new File("executable/setup.exe"));
fos.write(fileData);
fos.close();
Runtime.getRuntime().exec("executable/setup.exe", null, new File("executable/"));
}
catch(MalformedURLException m) {
System.out.println(m);
}
catch(IOException io) {
System.out.println(io);
}
}
}.start();
另外，我建议使用 ProcessBuilder 而不是 Runtime。
示例:
List<String> command = new ArrayList<String>();
command.add("cmd");
command.add("/C");
File dcr = new File("executable/setup.exe");
dcr.setExecutable(true, false);
command.add(dcr.getAbsolutePath());
ProcessBuilder builder = new ProcessBuilder(command);
builder.redirectErrorStream(true);
final Process process = builder.start();
try {
process.waitFor();
} catch (InterruptedException ex) {
Logger.getLogger(WhatEver.class.getName()).log(Level.SEVERE, null, ex);
throw ex;
}
InputStream is = process.getErrorStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String line;
while ((line = br.readLine()) != null) {
Logger.getLogger(Thumbnail.class.getName()).severe(line);
}
其次，Font 不正确，因为它在
处抛出异常Font sFont = Font.createFont(Font.TRUETYPE_FONT, new File("DUGFB___.TTF")); 因此字体不符合预期。
同时将 returnString == "看来您没有更新。" 更改为 returnString.equals("看来您没有更新。")
关于java - 下载时 JAR 不兼容，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15801837/