Java 如何将消息从FXML控制器类发送到主应用程序类

各位好，飞越者

我有一个问题“我有一个fxml文件”CrawlerView.fxml“和它的控制器”CrawlerController.java”，还有一个主应用程序类，我想从控制器类向主应用程序类发送消息（数据库插入）（因为我不能在GUI/fxml控制器类中执行业务逻辑）.所以我的问题是：是否可以将消息从fxml控制器类发送到主应用程序类“ 代码如下 有什么帮助吗 先发制人`

---

Crawler.java

---

CrawlerView.fxml

履带式控制器

package app.model.main；
导入java.net.URL；
导入java.sql.Statement；
导入java.util.ResourceBundle；
导入java.util.Stack；
导入javafx.event.ActionEvent；
导入javafx.event.EventHandler；
导入javafx.fxml.fxml；
导入javafx.fxml.Initializable；
导入javafx.scene.control.Button；
导入javafx.scene.control.TextField；
公共类CrawlerController实现可初始化
{
@FXML按钮搜索；
@FXML文本字段URL；
@Override//FXMLLoader在初始化完成时调用此方法
公共void初始化（URL fxmlFileLocation，ResourceBundle资源）{
断言搜索！=null：“fx:id=\“myButton\”未被注入：检查FXML文件“simple.FXML”；
SEARCH.setOnAction（新的EventHandler（）{
@凌驾
公共无效句柄（ActionEvent事件）
{
//如何向主应用程序类发送消息
}
});}
}

package app.model.main;

import java.io.IOException;
import java.sql.Statement;
import java.util.Stack;

import javafx.application.Application;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class Crawler extends Application {

private Stage MStage;
private BorderPane rootLayout;
@FXML Button SEARCH;
@FXML TextField URL;
static Conection conection;
static url_entries URLS;//self implemented classes
static word_count  count;//self implemented classes
static Statement stmt; 
//static public Stack DATABASE;

public static void test(){}

public static void main(String[] args)
{
    launch(args);
}


@Override
public void start(Stage MStage) 
{
    try {



        FXMLLoader RootLoader = new FXMLLoader();
        FXMLLoader CrawlerLoader = new FXMLLoader();

           RootLoader.setLocation(Crawler.class.getResource("view/RootView.fxml"));
        CrawlerLoader.setLocation(Crawler.class.getResource("view/CrawlerView.fxml"));

        rootLayout = (BorderPane) RootLoader.load();

        AnchorPane CV = (AnchorPane) CrawlerLoader.load();

        rootLayout.setCenter(CV);

        // Show the scene containing the root layout.
        Scene scene = new Scene(rootLayout);
        MStage.setScene(scene);
        MStage.show();

    } catch (IOException e) 
    {

            e.printStackTrace();
    }
}


}

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

<?import javafx.scene.effect.*?>
<?import javafx.scene.text.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane prefHeight="628.0" prefWidth="600.0"     xmlns="http://javafx.com/javafx/8.0.40" xmlns:fx="http://javafx.com/fxml/1"     fx:controller="app.model.main.CrawlerController">
   <children>
      <SplitPane dividerPositions="0.14424635332252836" layoutX="8.0" layoutY="-2.0" orientation="VERTICAL" prefHeight="628.0" prefWidth="600.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
        <items>
          <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="100.0" prefWidth="160.0">
           <children>
              <Label layoutX="105.0" layoutY="14.0" prefHeight="52.0" prefWidth="388.0" text="Khurasani Web Crawler" textFill="#792323">
                 <font>
                    <Font name="Bauhaus 93" size="34.0" />
                 </font>
              </Label>
           </children>
        </AnchorPane>
      <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="100.0" prefWidth="160.0">
           <children>
              <TextField id="URL" fx:id="URL" alignment="CENTER" blendMode="DARKEN" layoutX="110.0" layoutY="25.0" prefHeight="34.0" prefWidth="359.0" text="Enter URL">
                 <font>
                    <Font name="Berlin Sans FB Demi Bold" size="17.0" />
                 </font>
                 <effect>
                    <InnerShadow choke="0.56" color="#722424" height="26.93" radius="12.965" width="26.93" />
                 </effect>
              </TextField>
              <Button id="SEARCH" fx:id="SEARCH" layoutX="247.0" layoutY="82.0" mnemonicParsing="false" prefHeight="27.0" prefWidth="79.0" text="Search" textFill="#5e2929">
                 <font>
                    <Font name="Arial Black" size="15.0" />
                 </font>
              </Button>
           </children>
        </AnchorPane>
    </items>
  </SplitPane>

package app.model.main;


import java.net.URL;
import java.sql.Statement;
import java.util.ResourceBundle;
import java.util.Stack;


import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;

public class CrawlerController implements Initializable
{

    @FXML Button SEARCH;
    @FXML TextField URL; 


@Override // This method is called by the FXMLLoader when initialization is complete
public void initialize(URL fxmlFileLocation, ResourceBundle resources) {
    assert SEARCH != null : "fx:id=\"myButton\" was not injected: check your FXML file 'simple.fxml'.";


   SEARCH.setOnAction(new EventHandler<ActionEvent>() {

    @Override
    public void handle(ActionEvent event) 
    {

         //How to send message to main application class 
    }
});}



}