我真的很困惑：当我在Eclipse中正常运行程序时，我的某些代码不起作用，但是当我使用调试模式逐步运行每个步骤时，它确实有效。
代码：
public void showConnectDialog() {
ConnectDialog connectDialog = new ConnectDialog();
connectDialog.setVisible(true);
//Until here, code runs
while(! connectDialog.getConnected()) {};
//The next line does only run in debug
JOptionPane.showMessageDialog(connectDialog, "Connected", "Connected", JOptionPane.INFORMATION_MESSAGE);
}
连接器（在用户点击对话框中的“连接”时作为线程启动）：
private class ServerConnector implements ActionListener, Runnable {
@Override
public void actionPerformed(ActionEvent e) {
if (! IP_field.getText().equals("")) {
if (! isConnecting) {
new Thread(new ServerConnector(), "ServerConnector").start();
}
}
else {
JOptionPane.showMessageDialog(dialog,
"Enter an IP address",
"Enter IP",
JOptionPane.WARNING_MESSAGE);
}
}
@Override
public void run() {
try {
setConnecting(true);
Socket socket = connect();
if (socket != null) {
ObjectOutputStream oOut = new ObjectOutputStream(socket.getOutputStream());
ObjectInputStream oIn = new ObjectInputStream(socket.getInputStream());
if (login(oOut, oIn)) {
isConnected = true;
setConnecting(false);
}
else {
socket.close();
}
setConnecting(false);
}
}
catch (RSPException e) {
e.printStackTrace();
System.exit(1);
}
catch (Exception e) {
//If an exception occurs, setConnecting() will be true. This
//not good, so it has to be set to false
e.printStackTrace();
setConnecting(false);
}
}
private boolean login(ObjectOutputStream oOut, ObjectInputStream oIn)
throws ClassNotFoundException, IOException, RSPException {
//Send login request action:
oOut.writeObject(new LoginAction(ActionSender.CLIENT, getID(),
getPassword()));
Object obj = oIn.readObject();
if (obj instanceof LoginActionResult) {
LoginActionResult result = (LoginActionResult) obj;
if (result.getResult() == LoginResults.SUCCES) {
return true;
}
else if (result.getResult() == LoginResults.FAIL_ON_ID) {
JOptionPane.showMessageDialog(dialog,
"Invalid password or ID",
"Can't login",
JOptionPane.ERROR_MESSAGE);
return false;
}
else if (result.getResult() == LoginResults.FAIL_ON_PASSWORD) {
JOptionPane.showMessageDialog(dialog,
"Invalid password or ID",
"Can't login",
JOptionPane.ERROR_MESSAGE);
return false;
}
else if (result.getResult() == LoginResults.SERVER_FULL) {
JOptionPane.showMessageDialog(dialog,
"Couldn't connect: \n" +
"Server is full",
"Failed to connect",
JOptionPane.WARNING_MESSAGE);
return false;
}
else {
return false;
}
}
else {
System.out.println(obj);
throw new RSPException("Server is not following the protocol.");
}
}
private void setConnecting(boolean connecting) {
if (connecting) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
connectButton.setEnabled(false);
}
});
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
connectButton.setText("Connecting...");
}
});
}
else {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
connectButton.setText("Connect");
}
});
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
connectButton.setEnabled(true);
}
});
}
isConnecting = connecting;
}
private String getAddressFromTextField() {
return IP_field.getText();
}
private InetAddress getInetAddress(String fullAddress) {
try {
if (fullAddress.contains(":")) {
String[] splitAddress = fullAddress.split(":");
return InetAddress.getByName(splitAddress[0]);
}
else {
return InetAddress.getByName(fullAddress);
}
}
catch (UnknownHostException e) {
return null;
}
}
private int getPort(String fullAddress) {
try {
String[] splittedAddress = fullAddress.split(":");
return Integer.valueOf(splittedAddress[1]);
}
catch (NumberFormatException ex) {
return -1;
}
catch (NullPointerException
| ArrayIndexOutOfBoundsException
| PatternSyntaxException ex) {
//Returning default port value: 25566, because no port was given
return 25566;
}
}
@SuppressWarnings("resource")
private Socket connect() {
Socket socket = null;
InetAddress address = null;
if ((address = getInetAddress(getAddressFromTextField())) == null) {
return null;
}
int port = getPort(getAddressFromTextField());
try {
socket = new Socket(address, port);
}
catch (ConnectException e ) {
Socket retrySocket = null;
if ((retrySocket = retryConnect(address, port)) == null) {
JOptionPane.showMessageDialog(dialog,
"Connection timed out",
"Failed to connect",
JOptionPane.ERROR_MESSAGE);
setConnecting(false);
}
else {
socket = retrySocket;
}
}
catch(IOException e) {
e.printStackTrace();
}
return socket;
}
private Socket retryConnect(InetAddress address, int port) {
Thread waitThread = new Thread(new Runnable() {
@Override
public void run() {
try {
//Will wait 15(000) (milli)seconds before stopping with
//trying to connect.
//One second (1000 millis) is for debugging and testing
Thread.sleep(1000);
}
catch (InterruptedException e) {
e.printStackTrace();
}
}
});
waitThread.start();
while (waitThread.isAlive()) {
try {
return new Socket(address, port);
}
catch (ConnectException e) {
//Do nothing, will re-attempt to connect.
}
catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
private String getID() {
return ID_field.getText();
}
private String getPassword() {
if (getID().equals("master")) {
return "masterPassword";
}
else {
return new String(passwordField.getPassword());
}
}
}
getConnected()会在连接到服务器后立即返回true。连接器在一个单独的线程上运行。
编辑: 我试图在getConnected()函数中添加代码，然后它就可以正常工作了。为什么这时可以而其他情况不行呢？
ConnectDialog的代码吗？ - austinwait和notify。showConnectDialog会等待ServerConnector线程通知它。这样你就可以避免while循环，使程序不会阻塞CPU核心。 - TomisConnecting变量的定义位置... 它被定义为volatile了吗？https://docs.oracle.com/javase/tutorial/essential/concurrency/atomic.html - Nate