我的代码目前通过IMAP（imaps）和javamail读取我的Gmail收件箱，一旦找到带有zip / xap附件的电子邮件，它会显示一个阶段（窗口）询问是否下载该文件，是或否。
我希望在进行选择后关闭舞台，然后返回到来自呼叫的循环内的位置。我的问题出现是因为您无法多次启动应用程序，因此我在Platform.setImplicitExit(false);方法中写了start，然后使用primartyStage.hide()（？）当我需要稍后再次显示舞台时，我会像Platform.runLater(() -> primaryStage.show());那样。
现在出现的问题是命令流在Mail.java的doit()方法中开始，该方法在我的收件箱中循环，而launch(args)发生在for loop内。方法。这意味着launch(args)然后调用start来设置场景，并显示舞台。由于存在Controller.java和fxml关联，因此Controller类具有舞台按钮的事件处理程序，其中＆＃34;拦截＆＃34; start显示阶段后的流程。因此，当我单击是或否时，它会隐藏舞台，但只有挂起。好像它无法返回到start方法继续发生启动（args）的循环。如何在必要时正确隐藏/显示舞台，无论是否点击都允许循环继续。
这是Mail.java和Controller.java的代码。非常感谢！
Mail.java
[Other variables set here]
public static int launchCount = 0;@FXML public Text subjectHolder;
public static ReceiveMailImap obj = new ReceiveMailImap();
public static void main(String[] args) throws IOException, MessagingException {
ReceiveMailImap.doit();
}
@Override
public void start(Stage primaryStage) throws Exception {
loader = new FXMLLoader(getClass().getResource("prompts.fxml"));
root = loader.load();
controller = loader.getController();
controller.setPrimaryStage(primaryStage);
scene = new Scene(root, 450, 250);
controller.setPrimaryScene(scene);
scene.getStylesheets().add("styleMain.css");
Platform.setImplicitExit(false);
primaryStage.setTitle("Download this file?");
primaryStage.initStyle(StageStyle.UNDECORATED);
primaryStage.setScene(scene);
primaryStage.show();
}
public static void doit() throws MessagingException, IOException {
Folder inbox = null;
Store store = null;
try {
Properties props = System.getProperties();
Session session = Session.getDefaultInstance(props, null);
store = session.getStore("imaps");
store.connect("imap.gmail.com", "myAccount@gmail.com", "Password");
inbox = store.getFolder("Inbox");
inbox.open(Folder.READ_WRITE);
Message[] messages = inbox.getMessages();
FetchProfile fp = new FetchProfile();
fp.add(FetchProfile.Item.ENVELOPE);
fp.add(UIDFolder.FetchProfileItem.FLAGS);
fp.add(UIDFolder.FetchProfileItem.CONTENT_INFO);
fp.add("X-mailer");
inbox.fetch(messages, fp);
int doc = 0;
int maxDocs = 400;
for (int i = messages.length - 1; i >= 0; i--) {
Message message = messages[i];
if (doc < maxDocs) {
doc++;
message.getSubject();
if (!hasAttachments(message)) {
continue;
}
String from = "Sender Unknown";
if (message.getReplyTo().length >= 1) {
from = message.getReplyTo()[0].toString();
} else if (message.getFrom().length >= 1) {
from = message.getFrom()[0].toString();
}
subject = message.getSubject();
if (from.contains("myAccount@gmail.com")) {
saveAttachment(message.getContent());
message.setFlag(Flags.Flag.SEEN, true);
}
}
}
} finally {
if (inbox != null) {
inbox.close(true);
}
if (store != null) {
store.close();
}
}
}
public static boolean hasAttachments(Message msg) throws MessagingException, IOException {
if (msg.isMimeType("multipart/mixed")) {
Multipart mp = (Multipart) msg.getContent();
if (mp.getCount() > 1) return true;
}
return false;
}
public static void saveAttachment(Object content)
throws IOException, MessagingException {
out = null; in = null;
try {
if (content instanceof Multipart) {
Multipart multi = ((Multipart) content);
parts = multi.getCount();
for (int j = 0; j < parts; ++j) {
part = (MimeBodyPart) multi.getBodyPart(j);
if (part.getContent() instanceof Multipart) {
// part-within-a-part, do some recursion...
saveAttachment(part.getContent());
} else {
int allow = 0;
if (part.isMimeType("application/x-silverlight-app")) {
extension = "xap";
allow = 1;
} else {
extension = "zip";
allow = 1;
}
if (allow == 1) {
if (launchCount == 0) {
launch(args);
launchCount++;
} else {
Platform.runLater(() -> primaryStage.show());
}
} else {
continue;
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if ( in != null) { in .close();
}
if (out != null) {
out.flush();
out.close();
}
}
}
public static File createFolder(String subject) {
JFileChooser fr = new JFileChooser();
FileSystemView myDocs = fr.getFileSystemView();
String myDocuments = myDocs.getDefaultDirectory().toString();
dir = new File(myDocuments + "\\" + subject);
savePathNoExtension = dir.toString();
dir.mkdir();
System.out.println("Just created: " + dir);
return dir;
}
}
Controller.java
public class Controller implements Initializable {
@FXML
private Text subjectHolder;
public Button yesButton, noButton;
public ReceiveMailImap subject;
@Override
public void initialize(URL url, ResourceBundle rb) {
subject= new ReceiveMailImap();
subjectHolder.setText(subject.returnSubject());
}
public Stage primaryStage;
public Scene scene;
@FXML
ComboBox<String> fieldCombo;
public void setPrimaryStage(Stage stage) {
this.primaryStage = stage;
}
public void setPrimaryScene(Scene scene) {
this.scene = scene;
}
public String buttonPressed(ActionEvent e) throws IOException, MessagingException {
Object source = e.getSource();
if(source==yesButton){
System.out.println("How to tell Mail.java that user clicked Yes?");
return "POSITIVE";}
else{subject.dlOrNot("no");
System.out.println("How to tell Mail.java that user clicked No?");
primaryStage.hide();
return "NEGATIVE";}
}
}
答案 0 :(得分：2)
您发布的代码存在很多问题，但我只想尝试解决您提出的问题。
代码挂起的原因是Application.launch(...)
在应用程序退出之前不会返回
通常，您在这里误解了JavaFX应用程序的整个生命周期。您应该将start(...)方法视为＆＃34;传统＆＃34;中main(...)方法的等效方法。 Java应用程序。唯一需要注意的是start(...)是在FX应用程序线程上执行的，所以如果你需要执行任何阻塞代码，你需要将它放在后台线程中。
为方便起见，start(...)方法传递了Stage实例，因为最常见的做法是创建场景图并在舞台中显示它。您没有义务使用此阶段，您可以忽略它，只需在您需要时创建自己的阶段。
我认为您基本上可以按如下方式构建代码（但是，老实说，我在理解您正在做的事情上遇到很多麻烦）：
public class Mail extends Application {
@Override
public void start(Stage ignored) throws Exception {
Platform.setImplicitExit(false);
Message[] messages = /* retrieve messages */ ;
for (Message message : messages) {
if ( /* need to display window */) {
showMessage(message);
}
}
}
private void showMessage(Message message) {
FXMLLoader loader = new FXMLLoader(getClass().getResource("prompts.fxml"));
Parent root = loader.load();
Controller controller = loader.getController();
Scene scene = new Scene(root, 450, 250);
stage.setScene(scene);
stage.initStyle(StageStyle.UNDECORATED);
stage.setTitle(...);
// showAndWait will block execution until the window is hidden, so
// you can query which button was pressed afterwards:
stage.showAndWait();
if (controller.wasYesPressed()) {
// ...
}
}
// for IDEs that don't support directly launching a JavaFX Application:
public static void main(String[] args) {
launch(args);
}
}
显然，您决定是否显示窗口的逻辑更为复杂，但这将为您提供基本结构。
要检查按下了哪个按钮，请使用上面的showAndWait然后在控制器中执行
public class Controller {
@FXML
private Button yesButton ;
private boolean yesButtonPressed = false ;
public boolean wasYesPressed() {
return yesButtonPressed ;
}
// use different handlers for different buttons:
@FXML
private void yesButtonPressed() {
yesButtonPressed = true ;
closeWindow();
}
@FXML
private void noButtonPressed() {
yesButtonPressed = false ; // not really needed, but makes things clearer
closeWindow();
}
private void closeWindow() {
// can use any @FXML-injected node here:
yesButton.getScene().getWindow().hide();
}
}