JavaFX - 无法在登录时查询用户名

时间：2018-02-08 11:43:04

标签： database javafx login sqlite

我的登录应用程序出现问题，当用户尝试登录时，我看到了这个错误：

Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
at javafx.fxml.FXMLLoader$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.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:8413)
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.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$MouseEventNotification.run(GlassViewEventHandler.java:394)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$353(GlassViewEventHandler.java:432)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:431)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
... 48 more
Caused by: java.lang.NullPointerException
at Login.loginController.login(loginController.java:37)
... 58 more

它在这一行导航我进入loginController：

if (database.isLogin(username.getText(), password.getText())){

我的代码如下。

数据库类： 

        String createManagement = "CREATE TABLE IF NOT EXISTS Management (name varchar(255), surname varchar(255), username varchar(255), password varchar(255))";

public boolean insertManagement(String name, String surname, String username, String password) {
    try {
        PreparedStatement preparedStatement = connection.prepareStatement("insert into Management values (?,?,?,?);");
        preparedStatement.setString(1, name);
        preparedStatement.setString(2, surname);
        preparedStatement.setString(3, username);
        preparedStatement.setString(4, password);
        preparedStatement.execute();
    } catch (SQLException e) {
        System.out.println("Error with insert Management to the table");
        e.printStackTrace();
        return false;
    }
    return true;
}


public boolean isLogin(String username, String password) throws SQLException 
{
    PreparedStatement preparedStatement = null;
    ResultSet resultSet = null;
    String query = "SELECT * FROM Management where username = ?, password = ?";
    try {
        preparedStatement = connection.prepareStatement(query);
        preparedStatement.setString(1, username);
        preparedStatement.setString(2, password);

        resultSet = preparedStatement.executeQuery();
        if (resultSet.next()) {
            return true;
        }else {
            return false;
        }
    } catch (Exception e) {
        return false;
    }
}

管理模式 

public Management(String name, String surname, String username, String password){
    this.name = new SimpleStringProperty(name);
    this.surname = new SimpleStringProperty(surname);
    this.username = new SimpleStringProperty(username);
    this.password = new SimpleStringProperty(password);
}

public StringProperty name;
public StringProperty nameProperty(){return name;}
public void setName(String value){nameProperty().set(value);}
public String getName(){return nameProperty().get();}


public StringProperty surname;
public StringProperty surnameProperty(){return surname;}
public void setSurname(String value){surnameProperty().set(value);}
public String getSurname(){return surnameProperty().get();}

public StringProperty username;
public StringProperty usernameProperty(){return username;}
public void setUsername(String value){usernameProperty().set(value);}
public String getUsername(){return usernameProperty().get();}

public StringProperty password;
public StringProperty passwordProperty(){return password;}
public void setPassword(String value){passwordProperty().set(value);}
public String getPassword(){return passwordProperty().get();}
}

登录控制器 

public void login (ActionEvent actionEvent){
    try {
        if (database.isLogin(username.getText(), password.getText())){
            isConnected.setText("Connected");
        }else {
            System.out.println("Wrong username or password!");
        }
    }catch (SQLException e){
        System.out.println("Wrong username or password!");
        e.printStackTrace();
    }
}

0 个答案:

没有答案
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