在我的程序中，用户输入已存在于我的SQL数据库中的用户名和密码，并检查数据库以确保用户名和密码正确无误。但是，当我尝试输入数据并按下登录按钮时，我得到一个参数类型不匹配错误我已经得到它将数据添加到具有类似布局的数据库。这是我的代码：
数据库连接类：
public class DataBaseConnect {
public static Connection getConnection() throws Exception{
try{
//get connection to database
String url = "jdbc:mysql://localhost:3306/csgoopenerdatabase?autoReconnect=true&useSSL=false";
String user = "root";
String password = "hockey33";
Connection con = DriverManager.getConnection(url,user,password);
System.out.println("Connected to database!");
//execute sql query
//process result set
return con;
}catch(Exception e){
System.out.println(e);
}
return null;
}
}
控制器类：
public class LoginController implements Initializable {
@FXML
protected static TextField UsernameFieldL;
@FXML
protected static PasswordField PasswordFieldL;
@FXML
private void handleLoginBack(MouseEvent event) throws IOException{
Parent handleInventoryBackParent = FXMLLoader.load(getClass().getResource("LoginCreateBuffer.fxml"));
Scene OPBackScene = new Scene(handleInventoryBackParent);
Stage handleInventoryBackStage = (Stage) ((Node) event.getSource()).getScene().getWindow();
handleInventoryBackStage.setScene(OPBackScene);
handleInventoryBackStage.show();
}
@FXML
private void handleLoginContinue(MouseEvent event) throws IOException, Exception{
CheckDB();
}
public static void CheckDB() throws Exception{
try{
//get connection to database
Connection conn = DataBaseConnect.getConnection();
//create a statement
PreparedStatement checkInfo = conn.prepareStatement("SELECT * FROM userinfo WHERE Username='"+UsernameFieldL.getText()+"' AND '"+PasswordFieldL.getText()+"'");
//process result set
checkInfo.executeQuery();
System.out.println("complete");
}
catch(Exception e){
e.printStackTrace();
}
}
@Override
public void initialize(URL url, ResourceBundle rb) {
// TODO
}
}
ERROR：
java.lang.IllegalArgumentException: argument type mismatch
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:75)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:279)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1451)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:69)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:28)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Node.fireEvent(Node.java:6866)
at javafx.scene.control.Button.fire(Button.java:179)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:193)
at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:336)
at com.sun.javafx.scene.control.skin.SkinBase$4.handle(SkinBase.java:329)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:64)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:217)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:170)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:53)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:33)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3369)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3209)
at javafx.scene.Scene$MouseHandler.access$1900(Scene.java:3164)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1582)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2267)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:250)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:173)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:292)
at com.sun.glass.ui.View.handleMouseEvent(View.java:530)
at com.sun.glass.ui.View.notifyMouse(View.java:924)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:17)
at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:67)
at java.lang.Thread.run(Thread.java:745)
Exception in thread "JavaFX Application Thread"
答案 0 :(得分：2)
最后还有一个额外的引用，也缺少Password=：
PreparedStatement checkInfo = conn.prepareStatement("SELECT * FROM userinfo WHERE Username='"+UsernameFieldL.getText()+"' AND Password= + '"+PasswordFieldL.getText()+"'");
答案 1 :(得分：1)
如果我错了，我会在这里停下来并删除我的答案，但我猜你的事件是按下按钮。因此，您应该在代码中将MouseEvent更改为ActionEvent。