个人中心
gpt4 book ai didi

java - 运行 Javafx 应用程序时出错

转载 作者：行者123 更新时间：2023-11-29 08:44:53 26 4
gpt4 key购买 nike

您好，我是 Java 新手，在运行应用程序时遇到错误。应用程序运行但是当按钮单击事件 createStudent(ActionEvent event) 被调用时显示错误。我正在粘贴完整的错误堆栈跟踪。

javafx.fxml.LoadException: 
/home/user/IdeaProjects/JavaFxDemo/out/production/JavaFxDemo/resources/fxml/newStudent.fxml

    at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2601)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2571)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
    at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2409)
    at dashboard.Controller.createStudent(Controller.java:145)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
    at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Node.fireEvent(Node.java:8411)
    at javafx.scene.control.Button.fire(Button.java:185)
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
    at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:352)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:275)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:388)
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:387)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
    at com.sun.glass.ui.View.notifyMouse(View.java:937)
    at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
    at com.sun.glass.ui.gtk.GtkApplication.lambda$null$49(GtkApplication.java:139)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2566)
    ... 65 more
Caused by: java.sql.SQLException: Operation not allowed after ResultSet closed
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:910)
    at com.mysql.jdbc.ResultSet.checkClosed(ResultSet.java:666)
    at com.mysql.jdbc.ResultSet.next(ResultSet.java:7274)
    at dashboard.AdmissionController.initialize(AdmissionController.java:168)
    ... 75 more

我检查了下面位置的fxml文件是否有问题，没有问题。

javafx.fxml.LoadException: 
/home/user/IdeaProjects/JavaFxDemo/out/production/JavaFxDemo/resources/fxml/newStudent.fxml

请检查我的 Controller 文件

dashboard.Controller.java

package dashboard;

import java.io.IOException;
import java.net.URL;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.IdentityHashMap;
import java.util.Observable;
import java.util.ResourceBundle;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import dashboard.StudentMaster;
import database.DatabaseAccess;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.stage.Modality;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

import java.sql.Connection;

public class Controller {


    private Connection connection;

    @FXML
    private ResourceBundle resources;

    @FXML
    private URL location;

    @FXML
    private TableView<StudentMaster> studentTable;

    @FXML
    private TableColumn<StudentMaster, Integer> studID;

    @FXML
    private TableColumn<StudentMaster, String> studReg;

    @FXML
    private TableColumn<StudentMaster, String> stdAdm;

    @FXML
    private TableColumn<StudentMaster, String> stdName;

    @FXML
    private TableColumn<StudentMaster, String> stdClass;

    @FXML
    private TableColumn<StudentMaster, String> stdDiv;

    @FXML
    private TextField regBox;

    @FXML
    private TextField admBox;

    @FXML
    private TextField nameBox;

    @FXML
    private TextField classBox;

    @FXML
    private TextField divBox;

    @FXML
    private Button searchBtn;

    @FXML
    private Button createStudentBtn;

    private ObservableList<StudentMaster> data;



    public void buildData(String SQL)
    {
        data = FXCollections.observableArrayList();
        try {
            ResultSet rs = connection.createStatement().executeQuery(SQL);
            while(rs.next())
            {
                StudentMaster studentData = new StudentMaster();
                studentData.studentId.set(rs.getInt("student_id"));
                studentData.stdClass.set(rs.getString("student_std"));
                studentData.name.set(rs.getString("student_name"));
                studentData.admNo.set(rs.getString("student_admn_no"));
                studentData.regno.set(rs.getString("student_regno"));
                studentData.stdDiv.set(rs.getString("student_div"));
                data.add(studentData);
                studentTable.setItems(data);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    @FXML
    void initialize() {
        assert studentTable != null : "fx:id=\"studentTable\" was not injected: check your FXML file 'dashboard.fxml'.";
        assert studID != null : "fx:id=\"studID\" was not injected: check your FXML file 'dashboard.fxml'.";
        assert studReg != null : "fx:id=\"studReg\" was not injected: check your FXML file 'dashboard.fxml'.";
        assert stdAdm != null : "fx:id=\"stdAdm\" was not injected: check your FXML file 'dashboard.fxml'.";
        assert stdName != null : "fx:id=\"stdName\" was not injected: check your FXML file 'dashboard.fxml'.";
        assert stdClass != null : "fx:id=\"stdClass\" was not injected: check your FXML file 'dashboard.fxml'.";
        assert stdDiv != null : "fx:id=\"stdDiv\" was not injected: check your FXML file 'dashboard.fxml'.";

        DatabaseAccess newConnection = new DatabaseAccess();
        connection = newConnection.startConnection();
        String SQL = "Select * from student";
        buildData(SQL);
        newConnection.shutdown();

        loadDataToTable();

    }

    private void loadDataToTable()
    {
        studID.setCellValueFactory(new PropertyValueFactory<StudentMaster, Integer>("studentId"));
        studReg.setCellValueFactory(new PropertyValueFactory<StudentMaster, String>("regno"));
        stdName.setCellValueFactory(new PropertyValueFactory<StudentMaster, String>("name"));
        stdAdm.setCellValueFactory(new PropertyValueFactory<StudentMaster, String>("admNo"));
        stdClass.setCellValueFactory(new PropertyValueFactory<StudentMaster, String>("stdClass"));
        stdDiv.setCellValueFactory(new PropertyValueFactory<StudentMaster, String>("stdDiv"));
    }

    @FXML
    void createStudent(ActionEvent event)
    {
        FXMLLoader fxmlLoader;
        fxmlLoader = new FXMLLoader(getClass().getResource("/resources/fxml/newStudent.fxml"));
        try {
            Parent root1 = (Parent)fxmlLoader.load();
            AdmissionController admissionController = fxmlLoader.getController();
            admissionController.setStudentData(studentTable.getItems());
            Stage stage = new Stage();
            stage.initModality(Modality.APPLICATION_MODAL);
//            stage.initStyle(StageStyle.UNDECORATED);
            stage.setTitle("New Admission");
            stage.setScene(new Scene(root1));
            stage.show();
        } catch (IOException e)
        {
            e.printStackTrace();
        }
    }

    @FXML
    void searchBtnClicked(ActionEvent event)
    {
        String name = nameBox.getText();
        String regno = regBox.getText();
        String admno = admBox.getText();
        String stdClass = classBox.getText();

        String SQL = "Select * from student where student_name like '"+name+"%'";
        System.out.println(SQL);
        DatabaseAccess newConnection = new DatabaseAccess();
        connection = newConnection.startConnection();
        buildData(SQL);
        newConnection.shutdown();
        loadDataToTable();
    }

    public void reloadStudentTable()
    {
        loadDataToTable();
    }

}

dashboard.AdmissionController.java

package dashboard;

import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.Node;
import javafx.scene.control.Button;
import javafx.scene.control.ChoiceBox;
import javafx.scene.control.DatePicker;
import javafx.scene.control.TextArea;
import javafx.scene.control.TextField;
import javafx.scene.input.InputMethodEvent;
import javafx.scene.input.MouseEvent;
import javafx.stage.Stage;
import customlib.ExecuteSQL;
import dashboard.AvailableClasses;

import java.sql.ResultSet;
import java.sql.SQLException;

public class AdmissionController {


    @FXML
    private TextField nameBox;

    @FXML
    private ChoiceBox<String> classBox;

    @FXML
    private ChoiceBox<String> divBox;

    @FXML
    private TextField admBox;

    @FXML
    private TextField religionBox;

    @FXML
    private TextField casteBox;

    @FXML
    private TextArea addressBox;

    @FXML
    private DatePicker dobBox;

    @FXML
    private ChoiceBox<?> sexBox;

    @FXML
    private Button resetBtn;

    @FXML
    private Button cancelBtn;

    @FXML
    private Button doneBtn;

    @FXML
    void cancelBtnClicked(ActionEvent event)
    {
//        GET the current node of the event
        Node node = (Node)event.getSource();
        Stage stage = (Stage)node.getScene().getWindow();
        stage.close();
    }

    @FXML
    void classMouseClicked(MouseEvent event) throws SQLException {
        System.out.println("clicked");
    }

    private ObservableList<StudentMaster> data ;
    private ObservableList<AvailableClasses>totalClasses;

    public void setStudentData(ObservableList<StudentMaster> data)
    {
        this.data = data ;
    }

    @FXML
    void doneBtnClicked(ActionEvent event)
    {
        String name = nameBox.getText();
        Integer ref = 1;
        String standard = "1";
        String division  = "A";
        String admissionNo = admBox.getText();
        String sex = "M";
        String religion = religionBox.getText();
        String caste = casteBox.getText();
        String address = addressBox.getText();
        String SQLquery = "INSERT INTO student (student_name," +
                "fk_grp_ref,"+
                "student_std," +
                "student_div," +
                "student_admn_no," +
                "student_sex," +
                "student_religion," +
                "student_caste," +
                "student_address) " +
                "VALUES ('"+name+"','"+ref+"', '"+standard+"'," +
                " '"+division+"', '"+admissionNo+"', '"+sex+"', " +
                "'"+religion+"', '"+caste+"', '"+address+"')";

        ExecuteSQL newQuery = new ExecuteSQL();
        Integer executeStatus = newQuery.ExecuteSQL(SQLquery);
        if (executeStatus != 0)
        {
            System.out.println("Data Inserted");
        }
        else
        {
            System.out.println("Error in execution");
        }
        StudentMaster student = new StudentMaster();
        StudentMaster studentData = new StudentMaster();
        studentData.name.set(name);
        studentData.admNo.set(admissionNo);
        studentData.stdDiv.set(division);
        studentData.stdClass.set(standard);
        studentData.studentId.set(executeStatus);
        data.add(studentData);




//      Close the Window after successfully inserted

        Node node = (Node)event.getSource();
        Stage stage = (Stage)node.getScene().getWindow();
        stage.close();

    }

    @FXML
    void resetBtnClicked(ActionEvent event) {
        nameBox.setText("");
        addressBox.setText("");
        admBox.setText("");
        dobBox.getEditor().clear();
        religionBox.setText("");
        casteBox.setText("");
    }

    @FXML
    void initialize() throws SQLException {
        assert nameBox != null : "fx:id=\"nameBox\" was not injected: check your FXML file 'newStudent.fxml'.";
        assert classBox != null : "fx:id=\"classBox\" was not injected: check your FXML file 'newStudent.fxml'.";
        assert divBox != null : "fx:id=\"divBox\" was not injected: check your FXML file 'newStudent.fxml'.";
        assert admBox != null : "fx:id=\"admBox\" was not injected: check your FXML file 'newStudent.fxml'.";
        assert religionBox != null : "fx:id=\"religionBox\" was not injected: check your FXML file 'newStudent.fxml'.";
        assert casteBox != null : "fx:id=\"casteBox\" was not injected: check your FXML file 'newStudent.fxml'.";
        assert addressBox != null : "fx:id=\"addressBox\" was not injected: check your FXML file 'newStudent.fxml'.";
        assert dobBox != null : "fx:id=\"dobBox\" was not injected: check your FXML file 'newStudent.fxml'.";
        assert sexBox != null : "fx:id=\"sexBox\" was not injected: check your FXML file 'newStudent.fxml'.";
        assert resetBtn != null : "fx:id=\"resetBtn\" was not injected: check your FXML file 'newStudent.fxml'.";
        assert cancelBtn != null : "fx:id=\"cancelBtn\" was not injected: check your FXML file 'newStudent.fxml'.";
        assert doneBtn != null : "fx:id=\"doneBtn\" was not injected: check your FXML file 'newStudent.fxml'.";

        String query = "select * from class";
        ExecuteSQL newSelectClassesQuery = new ExecuteSQL();
        ResultSet rs = newSelectClassesQuery.GetClassesList(query);
        totalClasses = FXCollections.observableArrayList();
        while(rs.next())
        {
//            AvailableClasses classesData = new AvailableClasses();
            classBox.getItems().add(rs.getString("class_name"));
        }
        rs.close();
    }
}

ExecuteSQL.java//执行我的 SQL 查询

package customlib;


import database.DatabaseAccess;

import java.sql.*;

public class ExecuteSQL {
    private Connection connection;

    public Integer ExecuteSQL(String query)
    {
        DatabaseAccess newConnection = new DatabaseAccess();
        connection = newConnection.startConnection();
        try
        {
            PreparedStatement preparedStatement = (PreparedStatement) connection.prepareStatement(query);
            preparedStatement.executeUpdate();

            ResultSet rs = connection.createStatement().executeQuery("select last_insert_id() as last_id from student");
            int lastid = 0;
            while(rs.next())
            {
                lastid = rs.getInt("last_id");

            }

            newConnection.shutdown();
            return lastid;

        }
        catch (SQLException e)
        {
            e.printStackTrace();
            newConnection.shutdown();
            return 0;
        }


    }

    public ResultSet GetClassesList(String query)
    {
        DatabaseAccess newConnection = new DatabaseAccess();
        connection = newConnection.startConnection();
        ResultSet rs;
        try
        {
            rs = connection.createStatement().executeQuery(query);
            newConnection.shutdown();
            rs.close();
            return rs;

        }
        catch (SQLException e)
        {
            e.printStackTrace();
            newConnection.shutdown();
            rs = null;
            return rs;
        }

    }




}

编辑:添加 newStudent.fxml 文件

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.ChoiceBox?>
<?import javafx.scene.control.DatePicker?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.TextArea?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.Pane?>
<?import javafx.scene.text.Font?>

<Pane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="500.0" prefWidth="700.0" xmlns="http://javafx.com/javafx/8.0.65" xmlns:fx="http://javafx.com/fxml/1" fx:controller="dashboard.AdmissionController">
   <children>
      <Pane layoutX="67.0" layoutY="92.0">
         <children>
            <TextField fx:id="nameBox" layoutX="64.0" layoutY="1.0" />
            <ChoiceBox fx:id="classBox" layoutX="299.0" onMouseClicked="#classMouseClicked" prefHeight="26.0" prefWidth="61.0" />
            <ChoiceBox fx:id="divBox" layoutX="396.0" layoutY="1.0" prefHeight="26.0" prefWidth="61.0" />
            <Label layoutY="6.0" prefHeight="16.0" prefWidth="49.0" text="Name" />
            <Label layoutX="257.0" layoutY="6.0" prefHeight="16.0" prefWidth="38.0" text="Class" />
            <Label layoutX="368.0" layoutY="5.0" prefHeight="16.0" prefWidth="38.0" text="Div" />
            <TextField fx:id="admBox" layoutX="64.0" layoutY="52.0" />
            <Label layoutX="2.0" layoutY="57.0" prefHeight="16.0" prefWidth="61.0" text="Adm.No" />
            <TextField fx:id="religionBox" layoutX="64.0" layoutY="98.0" />
            <Label layoutX="2.0" layoutY="103.0" prefHeight="16.0" prefWidth="61.0" text="Religion" />
            <TextField fx:id="casteBox" layoutX="63.0" layoutY="145.0" />
            <Label layoutX="1.0" layoutY="150.0" prefHeight="16.0" prefWidth="61.0" text="Caste" />
            <Label layoutX="251.0" layoutY="58.0" prefHeight="16.0" prefWidth="61.0" text="Address" />
            <TextArea fx:id="addressBox" layoutX="306.0" layoutY="50.0" prefHeight="116.0" prefWidth="267.0" />
            <Label layoutX="1.0" layoutY="196.0" prefHeight="16.0" prefWidth="61.0" text="DOB" />
            <DatePicker fx:id="dobBox" layoutX="61.0" layoutY="192.0" prefHeight="26.0" prefWidth="170.0" />
            <ChoiceBox fx:id="sexBox" layoutX="500.0" layoutY="1.0" prefHeight="26.0" prefWidth="61.0" />
            <Label layoutX="472.0" layoutY="5.0" prefHeight="16.0" prefWidth="38.0" text="Sex" />
            <Button fx:id="resetBtn" layoutX="2.0" layoutY="272.0" mnemonicParsing="false" onAction="#resetBtnClicked" text="Reset" />
            <Button fx:id="cancelBtn" layoutX="425.0" layoutY="271.0" mnemonicParsing="false" onAction="#cancelBtnClicked" text="Cancel" />
            <Button fx:id="doneBtn" layoutX="512.0" layoutY="269.0" mnemonicParsing="false" onAction="#doneBtnClicked" prefHeight="26.0" prefWidth="62.0" text="Done" />
         </children>
      </Pane>
      <Label layoutX="261.0" layoutY="40.0" prefHeight="25.0" prefWidth="170.0" text="NEW ADMISSION">
         <font>
            <Font size="20.0" />
         </font>
      </Label>
   </children>
</Pane>

最佳答案

问题是，getClassesList 返回一个已经关闭的结果集:

 try {
     rs = connection.createStatement().executeQuery(query);
     newConnection.shutdown(); // why shut down the connection when you plan to work on rs?
     rs.close(); // same question applies here
     return rs;
 }

但是在您的 AdmissionController 中您想要使用 ResultSet:

ResultSet rs = newSelectClassesQuery.GetClassesList(query); // already closed!
totalClasses = FXCollections.observableArrayList();
while(rs.next()) // exception
{
    // AvailableClasses classesData = new AvailableClasses();
    classBox.getItems().add(rs.getString("class_name"));
}
rs.close();

提示:重构您的类 ;-)

如果你问我，你应该考虑创建 DAO，从数据库获取和返回你的类。那么您的 UI 代码就不需要了解 ResultSet 生命周期。

关于java - 运行 Javafx 应用程序时出错，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37078262/

26 4 0
文章推荐： java - 接口(interface)与函数调用的 Kotlin 性能
文章推荐： bash - npm adduser 通过 bash
文章推荐： vim - 为什么 vim 在打开文件后将第一个字母更改为 g
文章推荐： bash - 如何通过命令行检查校验和？
行者123
个人简介

我是一名优秀的程序员,十分优秀！

滴滴打车优惠券免费领取
滴滴打车优惠券
全站热门文章
Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com