The link:{javadocPath}/org/gradle/api/file/CopySpec.html[CopySpec] interface, which the `Copy` task implements, offers:

* A link:{javadocPath}/org/gradle/api/file/CopySpec.html#from-java.lang.Object++...++-[CopySpec.from(java.lang.Object...)] method to define what to copy

     * to configure the {@link CopySpec} before it is returned by this method.
     *
     * @see #copySpec(Closure)
     * @param action Action to configure the CopySpec
     * @return The CopySpec
     */
    CopySpec copySpec(Action<? super CopySpec> action);

    /**

        return Actions.with(copySpec(), action);
    }

    @Override
    public CopySpec copySpec() {
        return getFileOperations().copySpec();
    }

    @Inject
    @Override
    public abstract ProcessOperations getProcessOperations();

    @Override
    public ExecResult javaexec(Closure closure) {

Method <org.gradle.api.file.CopySpec.exclude(groovy.lang.Closure)> has arguments/return type groovy.lang.Closure that is not Gradle public API or primitive or built-in JDK classes or Kotlin classes in (CopySpec.java:0)
Method <org.gradle.api.file.CopySpec.exclude(groovy.lang.Closure)> has arguments/return type groovy.lang.Closure that is not Gradle public API or primitive or built-in JDK classes or Kotlin classes in (CopySpec.java:0)

            'out.txt',
            'file1.txt',
            'sub/file2.txt'
        )
    }

    def "copy with CopySpec"() {
        given:
        buildScript '''
            def parentSpec = copySpec {
                from 'src'
                exclude '**/ignore/**'
                include '*/*.a'
                into 'subdir'
            }

 * You can no longer pass `null` as the configuration action of link:{javadocPath}/org/gradle/api/file/CopySpec.html#from-java.lang.Object-org.gradle.api.Action-[CopySpec.from(Object, Action)].
 * For better compatibility with the Kotlin DSL, link:{javadocPath}/org/gradle/api/file/DuplicatesStrategy.html[CopySpec.duplicatesStrategy] is no longer nullable. The property setter no longer accepts `null` as a way

| A task input or output property or a script variable to capture the result of using `project.resource` to calculate the actual parameter.

| `project.copySpec {}`
| link:{javadocPath}/org/gradle/api/file/FileSystemOperations.html#copySpec--[FileSystemOperations.copySpec {}]

| `project.copy {}`
| link:{javadocPath}/org/gradle/api/file/FileSystemOperations.html#copy-org.gradle.api.Action-[FileSystemOperations.copy {}]