copySpec.duplicatesStrategy = duplicatesStrategy
            copySpec.includeEmptyDirs = includeEmptyDirs
            copySpec.isCaseSensitive = isCaseSensitive
            copySpec.filteringCharset = filteringCharset
            if (dirMode != null) {
                copySpec.dirPermissions.set(fileSystemOperations.permissions(dirMode))
            }
            if (fileMode != null) {

    public void setFilteringCharset(String charset) {
        Preconditions.checkNotNull(charset, "filteringCharset must not be null");
        if (!Charset.isSupported(charset)) {
            throw new InvalidUserDataException(String.format("filteringCharset %s is not supported by your JVM", charset));
        }
        this.filteringCharset = charset;
    }

    private static class MapBackedExpandAction implements Action<FileCopyDetails> {

val copyResourcesTemplates = tasks.register<Copy>("copyResourcesTemplates") {
  from("src/main/resources-templates")
  into("$buildDir/generated/resources-templates")
  expand("projectVersion" to "${project.version}")
  filteringCharset = Charsets.UTF_8.toString()
}

kotlin {
  sourceSets {
    val main by getting {
      resources.srcDir(copyResourcesTemplates.get().outputs)
    }
  }
}

dependencies {

val copyKotlinTemplates = tasks.register<Copy>("copyKotlinTemplates") {
  from("src/main/kotlinTemplates")
  into("$buildDir/generated/sources/kotlinTemplates")
  expand("projectVersion" to project.version)
  filteringCharset = Charsets.UTF_8.toString()
}

// Build & use okhttp3/internal/idn/IdnaMappingTableInstance.kt
val generateIdnaMappingTableConfiguration: Configuration by configurations.creating
dependencies {

    filter { String line ->
        "[$line]"
    }
    // Use a closure to remove lines
    filter { String line ->
        line.startsWith('-') ? null : line
    }
    filteringCharset = 'UTF-8'
}
// end::filter-files[]

// tag::file-permissions[]
tasks.register('permissions', Copy) {
    from 'src/main/webapp'
    into layout.buildDirectory.dir('explodedWar')
    filePermissions {

    filter { line: String ->
        "[$line]"
    }
    // Use a closure to remove lines
    filter { line: String ->
        if (line.startsWith('-')) null else line
    }
    filteringCharset = "UTF-8"
}
// end::filter-files[]

// tag::file-permissions[]
tasks.register<Copy>("permissions") {
    from("src/main/webapp")
    into(layout.buildDirectory.dir("explodedWar"))

            getInputs().property(specPropertyName + ".filePermissions", spec.getFilePermissions().map(FilePermissions::toUnixNumeric))
                .optional(true);
            getInputs().property(specPropertyName + ".filteringCharset", (Callable<String>) spec::getFilteringCharset);
        });
        this.getOutputs().doNotCacheIf(
            "Has custom actions",
            spec(task -> rootSpec.hasCustomActions())
        );

        "filePermissions"    | "filePermissions { unix(\"0600\") }"              | "filePermissions { unix(\"0644\") }"
        "filteringCharset"   | "filteringCharset = 'iso8859-1'"                  | "filteringCharset = 'utf-8'"
    }

    def "null action is forbidden for #method"() {
        given:
        buildScript """
            task copy(type: Copy) {