图片 url 是如何用 java fxml 写的

Posted 2023-03-15

【中文标题】图片 url 是如何用 java fxml 写的

【英文标题】：How the image url is wrriten in java fxml

【发布时间】：2019-07-02 20:49:10

【问题描述】：

我正在使用 fxml 文件，但我不知道如何将 url（路径）写入我拥有的图像，我尝试了绝对路径和目录路径

我收到一个无效的 url 错误，例如 >>

Feb 08, 2019 5:09:27 PM javafx.fxml.FXMLLoader$ValueElement processValue
WARNING: Loading FXML document with JavaFX API of version 11.0.1 by 
JavaFX runtime of version 10.0.2
null/bars-chart.png
Exception in Application start method
java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:473)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:372)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:941)
Caused by: java.lang.RuntimeException: Exception in Application start method
at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:973)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:198)
at java.base/java.lang.Thread.run(Thread.java:844)
Caused by: javafx.fxml.LoadException: 
unknown path:64

at javafx.fxml/javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2625)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2603)
at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:2450)
at back_end.image_main.start(image_main.java:25)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:919)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$11(PlatformImpl.java:449)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$9(PlatformImpl.java:418)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:417)
at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:175)
... 1 more
Caused by: java.lang.IllegalArgumentException: Invalid URL: Invalid URL or resource not found
at javafx.graphics/javafx.scene.image.Image.validateUrl(Image.java:1107)
at javafx.graphics/javafx.scene.image.Image.<init>(Image.java:688)
at javafx.fxml/com.sun.javafx.fxml.builder.JavaFXImageBuilder.build(JavaFXImageBuilder.java:47)
at javafx.fxml/com.sun.javafx.fxml.builder.JavaFXImageBuilder.build(JavaFXImageBuilder.java:37)
at javafx.fxml/javafx.fxml.FXMLLoader$ValueElement.processEndElement(FXMLLoader.java:771)
at javafx.fxml/javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:2838)
at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2557)
... 11 more
Caused by: java.lang.IllegalArgumentException: Invalid URL or resource not found
at javafx.graphics/javafx.scene.image.Image.validateUrl(Image.java:1099)
... 17 more
Exception running application back_end.image_main

我的项目结构是

fxml_image :
           src :
                front_end :
                           >(bars-chart.png)
                           >(main.fxml)
                back_end :
                           >(image_main.java)

这个块是我的（main.fxml）的一部分>>

    
    <AnchorPane maxHeight="-1.0" maxWidth="-1.0" prefHeight="-1.0" prefWidth="-1.0" VBox.vgrow="ALWAYS">
      <children>
        <Label alignment="CENTER" layoutX="155.0" layoutY="177.0" style="&#10;" text="Drag components from Library here…" textAlignment="CENTER" textFill="#9f9f9f" wrapText="false">
          <font>
            <Font size="18.0" />
          </font>
            </Label>
                <ImageView fitHeight="349.0" fitWidth="606.0" layoutX="12.0"         layoutY="11.0" pickOnBounds="true" preserveRatio="true">
                   <image>
                      <Image url="@bars-chart.png" />
                   </image>
                </ImageView>
          </children>
        </AnchorPane>

这是java文件（image_main）

    package back_end;

    import java.io.FileInputStream;
    import java.io.IOException;
    import javafx.application.Application;
    import javafx.fxml.FXMLLoader;
    import javafx.scene.Scene;
    import javafx.scene.layout.VBox;
    import javafx.stage.Stage;

    public class image_main extends Application  
    
        public static void main(String[] args)  Application.launch(args); 
        
        @Override 
        public void start(Stage stage) throws IOException  
        
        // Create the FXMLLoader 
        FXMLLoader loader = new FXMLLoader(); 
        // Path to the FXML File 
        String fxmlDocPath = "src/front_end/main.fxml"; 
        FileInputStream fxmlStream = new FileInputStream(fxmlDocPath);
        // Create the Pane and all Details 
        VBox root = (VBox) loader.load(fxmlStream);
        // Create the Scene 
        Scene scene = new Scene(root); 
        // Set the Scene to the Stage 
        stage.setScene(scene); 
        // Set the Title to the Stage 
        stage.setTitle("A FXML Example which includes FXML Files"); 
        // Display the Stage 
        stage.show();
    

    

是否有另一种加载 FXML 的方法，如何解释图像链接

【问题讨论】：

请遵守 java 命名约定

【参考方案1】：

我不建议您将图像文件包含在“src”文件夹中。您应该创建一个名为“res”的新文件夹并将其作为源文件夹（选项 -> 构建路径 -> 用作源文件夹）。将您的图像放在“res”文件夹中。然后在fxml文件中做如下修改。

<Image url="@../bars-chart.png" />

我希望这对你有用。

【参考方案2】：

使用 fxml 文件的位置解析路径。如果您使用 InputStream 作为 fxml 数据的源来加载 fxml，FXMLLoader 无法确定位置 url。

改为指定位置：

FXMLLoader loader = new FXMLLoader(new File("src/front_end/main.fxml").toURI().toURL());
VBox root = (VBox) loader.load();

假设 fxml 是一种资源，我建议使用 getResource 来获取 url：

FXMLLoader loader = new FXMLLoader(getClass().getResource("/front_end/main.fxml"));