如何使用普通的 gradle cli 编译和构建从 intellij 生成的 UI 表单？

Question

我已经使用 intellij IDE GUI 表单生成了简单的 UI。生成的 java 文件：

import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class App {
    private JButton buttonMessage;
    private JPanel panelMain;

    public App() {
        buttonMessage.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                JOptionPane.showMessageDialog(null, "hello world");
            }
        });
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame();
        frame.setContentPane(new App().panelMain);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}

还有我的

build.gradle.kts

:

/*
 * This file was generated by the Gradle 'init' task.
 *
 * This generated file contains a sample Java application project to get you started.
 * For more details on building Java & JVM projects, please refer to https://docs.gradle.org/8.3/userguide/building_java_projects.html in the Gradle documentation.
 */

plugins {
    // Apply the application plugin to add support for building a CLI application in Java.
    application
}

repositories {
    // Use Maven Central for resolving dependencies.
    mavenCentral()
}

dependencies {
    // Use JUnit Jupiter for testing.
    testImplementation("org.junit.jupiter:junit-jupiter:5.9.3")

    testRuntimeOnly("org.junit.platform:junit-platform-launcher")

    // This dependency is used by the application.
    implementation("com.google.guava:guava:32.1.1-jre")

    // ADDED DEPENDENCY HERE
    implementation("com.intellij:forms_rt:7.0.3")
}

// Apply a specific Java toolchain to ease working on different environments.
java {
    toolchain {
        languageVersion.set(JavaLanguageVersion.of(8))
    }
}

application {
    // Define the main class for the application.
    mainClass.set("com.example.j3.App")
}

tasks.named<Test>("test") {
    // Use JUnit Platform for unit tests.
    useJUnitPlatform()
}

现在即使添加了依赖项

implementation("com.intellij:forms_rt:7.0.3")

按照此处的建议https://intellij-support.jetbrains.com/hc/en-us/community/posts/206152369-idea-IC-gradle-and-swing-forms，在构建并运行 jar 后，我得到

Exception in thread "main" java.lang.NullPointerException
        at com.example.j3.App.<init>(App.java:12)
    at com.example.j3.App.main(App.java:22)

这是有道理的，因为我在构造函数中没有看到

panelMain

的初始化，而是在

new App().panelMain

中未初始化（因此为空）使用。但如果我尝试将构造函数中的

panelMain

初始化为

panelMain = new JPanel();

，那么 IDE 会抱怨：

Assignment to UI-bound field will overwrite field generated by UI Designer 

因此，一方面，UI 设计器将尝试在构建时初始化 UI 生成的字段（

buttonMessage

和

panelMain

），但另一方面，它不会向 gradle 通知这样做。因此，如果我

gradle clean build

然后

java -cp app/build/libs/app.jar com.example.j3.App

，那么我会得到空指针异常，因为

gradle build

不考虑 intellij 设计器初始化。那么有没有办法解决这个问题呢？

Answer 1

我也遇到了同样的问题。使用这个插件。有用 https://github.com/File5/intellij-idea-guidesigner-plugin