SendMail 方法在我的程序中不起作用，但在新文件上起作用

Question

我目前正在編寫一個帶有 function 的程序，它允許用戶重置密碼。 我已經嘗試了很多代碼，並找到了一個使用 outlook 對我有用的代碼。當我第一次在我的大項目之外的一個單獨項目上使用這段代碼時，它運行得很好。 但是當我將它復制粘貼到我的大項目中時，它給了我錯誤。

這是我的 class 的完整代碼passwordResetEmail

package IA;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.stage.Stage;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Properties;

public class passwordResetEmail extends Utility {

    @FXML
    Button button_exit;

    @FXML
    Button button_back;

    @FXML
    static
    TextField textField_email;

    @FXML
    Button button_sendCode;



    public void exit(){
        Stage stage = (Stage) button_exit.getScene().getWindow();
        stage.close();
    }

    private Stage stage;
    private Scene scene;


    public void back(ActionEvent event) throws IOException {

        Parent root = FXMLLoader.load(getClass().getResource("OpeningPage.fxml"));
        stage = (Stage)((Node)event.getSource()).getScene().getWindow();
        scene = new Scene(root);
        stage.setScene(scene);
        stage.show();

    }

    public static void sendMail(String email) throws MessagingException, IOException, SQLException {

        String emailFrom = "xxx.outlook.com";
        String password = "xxx";
        String emailTo = String.valueOf(email);

        Properties properties = new Properties();
        properties.put("mail.smtp.host", "smtp.office365.com");
        properties.setProperty("mail.smtp.starttls.enable","true");
        properties.put("mail.smtp.ssl.trust","smtp.office365.com");
        properties.setProperty("mail.smtp.port","587");
        properties.setProperty("mail.smtp.user", emailFrom);
        properties.setProperty("mail.smtp.auth", "true");

        Session session = Session.getDefaultInstance(properties);
        MimeMessage message = new MimeMessage(session);
        message.setFrom(new InternetAddress(emailFrom));
        message.addRecipient(Message.RecipientType.TO, new InternetAddress(emailTo));
        message.setSubject("Password reset");
        message.setText("Your password reset code is: ");

        Transport t = session.getTransport("smtp");
        t.connect(emailFrom, password);
        t.sendMessage(message,message.getAllRecipients());
        t.close();

    }

    public void sendCode() throws MessagingException, SQLException, IOException {
        sendMail(String.valueOf(textField_email));
    }
}

這是在我的 JavaFX GUI 中使用 sendCode() 時出現的錯誤

Nov 10, 2022 11:51:26 AM javafx.scene.CssStyleHelper calculateValue
WARNING: Caught 'java.lang.ClassCastException: class java.lang.String cannot be cast to class javafx.scene.paint.Paint (java.lang.String is in module java.base of loader 'bootstrap'; javafx.scene.paint.Paint is in module javafx.graphics of loader 'app')' while converting value for '-fx-background-color' from inline style on Button[id=button_signup, styleClass=button]'SIGN UP'
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at javafx.fxml/javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1857)
    at javafx.fxml/javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1724)
    at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:234)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at javafx.base/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.base/javafx.event.Event.fireEvent(Event.java:198)
    at javafx.graphics/javafx.scene.Node.fireEvent(Node.java:8792)
    at javafx.controls/javafx.scene.control.Button.fire(Button.java:203)
    at javafx.controls/com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:208)
    at javafx.controls/com.sun.javafx.scene.control.inputmap.InputMap.handle(InputMap.java:274)
    at javafx.base/com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:247)
    at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:234)
    at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at javafx.base/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at javafx.base/com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.base/javafx.event.Event.fireEvent(Event.java:198)
    at javafx.graphics/javafx.scene.Scene$MouseHandler.process(Scene.java:3897)
    at javafx.graphics/javafx.scene.Scene.processMouseEvent(Scene.java:1878)
    at javafx.graphics/javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2623)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:411)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:301)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$2(GlassViewEventHandler.java:450)
    at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:424)
    at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:449)
    at javafx.graphics/com.sun.glass.ui.View.handleMouseEvent(View.java:557)
    at javafx.graphics/com.sun.glass.ui.View.notifyMouse(View.java:943)
    at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:184)
    at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:568)
    at com.sun.javafx.reflect.Trampoline.invoke(MethodUtil.java:77)
    at jdk.internal.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:568)
    at javafx.base/com.sun.javafx.reflect.MethodUtil.invoke(MethodUtil.java:275)
    at javafx.fxml/com.sun.javafx.fxml.MethodHelper.invoke(MethodHelper.java:84)
    at javafx.fxml/javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1854)
    ... 46 more
Caused by: java.lang.NoClassDefFoundError: javax/activation/DataHandler
    at IA.computerscienceia/IA.passwordResetEmail.sendMail(passwordResetEmail.java:73)
    at IA.computerscienceia/IA.passwordResetEmail.sendCode(passwordResetEmail.java:87)
    ... 57 more
Caused by: java.lang.ClassNotFoundException: javax.activation.DataHandler
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
    ... 59 more

在這個最終代碼之前，我包含了一個不會真正起作用的代碼，它會生成一個隨機字符串，但是，我已經刪除了它以首先處理它。

我嘗試重命名 class，下載 activation.jar 並將其實施到我的方法中，我真的不記得還有什么，但我已經嘗試了很多次但它不起作用。

Answer 1

在這部分代碼中，您嘗試發送 TextField object 的字符串表示形式。

    public void sendCode() throws MessagingException, SQLException, IOException {
        sendMail(String.valueOf(textField_email));
    }

您可能想要發送 TextField 的文本值：

sendMail(textField_email.getText());

在嘗試向其發送 email 之前，您還應該驗證 TextField 的文本值以確保 String 具有有效的 email 地址格式。