Java 如何在应用程序编译时使用android.jar？

我在Gradle中编写了一个任务，在编译为apk之前，它应该更改资源中的映像（使用MyImageShifter类）

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ImageShifter使用android.graphics.Bitmap和android.graphics.BitmapFactory，但当我运行应用程序时，它在任务changeImage时失败。堆栈跟踪：

> Task :app:changeImage FAILED
Exception in thread "main" java.lang.NoClassDefFoundError: android/graphics/BitmapFactory
    at com.noname.watracker.ImageShifter.main(ImageShifter.java:33)
Caused by: java.lang.ClassNotFoundException: android.graphics.BitmapFactory
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:419)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:352)
    ... 1 more

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:changeImage'.

33行输入图像移位器：

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tasks.withType(JavaCompile) {
    compileTask -> apply {
        compileTask.finalizedBy changeImage
    }
}

> Task :app:changeImage FAILED
Exception in thread "main" java.lang.NoClassDefFoundError: android/graphics/BitmapFactory
    at com.noname.watracker.ImageShifter.main(ImageShifter.java:33)
Caused by: java.lang.ClassNotFoundException: android.graphics.BitmapFactory
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:419)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:352)
    ... 1 more

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:changeImage'.

Bitmap bitmap = BitmapFactory.decodeFile(file.getPath());