Bump to Gradle 8.10.2, require Java 11

Bump Gradle from 6.8.3 to 8.10.2 and increase the minimum required
Java version from 8 to 11 (SMACK-953).

The switch from Java 8 to 11 caused some Bytecode portability issues
regarding NIO Buffers. Java changed with version 9 the return type of
some subclasses of Buffer to return the specific Buffer type instead
of the Buffer superclass [JDK-4774077]. For example, ByteBuffer.filp()
previously returned Buffer, while it does return ByteBuffer now.

This sensible change was not reflected by the Android API [1], which
means that AnimalSniffer rightfully started to complain that there is
no method "ByteBuffer ByteBuffer.flip()" in Android, there is only
"Buffer ByteBuffer.flip()", and those are incompatible methods on
Java's Bytecode layer.

As workaround, this changes

    return charBuffer.flip().toString();

to

    ((java.nio.Buffer) charBuffer).flip();
    return charBuffer.toString();

to restore the Bytecode portability between Android and Java.

Errorprone also got new checks, of which JavaUtilDate and JdkObsolete
are wroth mentioning.

JavaUtilData basically strongly recommends to use Java's newer time
API over java.util.Date. But since Smack was Java 8 until now,
j.u.Date is widely used.

Similar JdkObsolete mentions obsolete JDK APIs, like data structures
like Vector and Stack. But mostly LinkedList, which should usually be
replaced by ArrayList. And this is what this commit largely does.

JDK-4774077: https://bugs.openjdk.org/browse/JDK-4774077
1: https://issuetracker.google.com/issues/369219141

build-logic/build.gradle

@@ -0,0 +1,16 @@
+plugins {
+	id 'groovy-gradle-plugin'
+}
+
+repositories {
+	gradlePluginPortal()
+}
+
+dependencies {
+	implementation "biz.aQute.bnd:biz.aQute.bnd.gradle:7.0.0"
+	implementation "io.freefair.gradle:maven-plugin:8.10" // for io.freefair.agregate-javadoc
+	implementation "me.champeau.jmh:jmh-gradle-plugin:0.7.2"
+	implementation "net.ltgt.gradle:gradle-errorprone-plugin:4.0.1"
+	implementation "gradle.plugin.org.kt3k.gradle.plugin:coveralls-gradle-plugin:2.12.2"
+	implementation "ru.vyarus:gradle-animalsniffer-plugin:1.7.1"
+}

build-logic/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = 'smack-build-logic'

build-logic/src/main/groovy/org.igniterealtime.smack.android-boot-classpath-conventions.gradle

@@ -0,0 +1,6 @@
+compileJava {
+	options.bootstrapClasspath = files(androidBootClasspath)
+}
+javadoc {
+	classpath += files(androidBootClasspath)
+}

build-logic/src/main/groovy/org.igniterealtime.smack.android-conventions.gradle

@@ -0,0 +1,10 @@
+plugins {
+	id 'ru.vyarus.animalsniffer'
+	id 'org.igniterealtime.smack.global-conventions'
+}
+dependencies {
+	signature "net.sf.androidscents.signature:android-api-level-${smackMinAndroidSdk}:5.0.1_r2@signature"
+}
+animalsniffer {
+	sourceSets = [sourceSets.main]
+}

build-logic/src/main/groovy/org.igniterealtime.smack.application-conventions.gradle

@@ -0,0 +1,12 @@
+plugins {
+	id 'application'
+}
+
+application {
+	applicationDefaultJvmArgs = ["-enableassertions"]
+}
+
+run {
+	// Pass all system properties down to the "application" run
+	systemProperties System.getProperties()
+}

build-logic/src/main/groovy/org.igniterealtime.smack.global-conventions.gradle

@@ -0,0 +1,37 @@
+ext {
+	javaVersion = JavaVersion.VERSION_11
+	javaMajor = javaVersion.getMajorVersion()
+	smackMinAndroidSdk = 21
+
+	androidBootClasspath = { getAndroidRuntimeJar() }
+}
+
+repositories {
+	mavenLocal()
+	mavenCentral()
+}
+
+def getAndroidRuntimeJar() {
+	def androidApiLevel = ext.smackMinAndroidSdk
+	def androidHome = getAndroidHome()
+	def androidJar = new File("$androidHome/platforms/android-${androidApiLevel}/android.jar")
+	if (androidJar.isFile()) {
+		return androidJar
+	} else {
+		throw new Exception("Can't find android.jar for API level ${androidApiLevel}. Please install corresponding SDK platform package")
+	}
+}
+def getAndroidJavadocOffline() {
+	def androidHome = getAndroidHome()
+	return androidHome.toString() + "/docs/reference"
+}
+
+def getAndroidHome() {
+	def androidHomeEnv = System.getenv("ANDROID_HOME")
+	if (androidHomeEnv == null) {
+		throw new Exception("ANDROID_HOME environment variable is not set")
+	}
+	def androidHome = new File(androidHomeEnv)
+	if (!androidHome.isDirectory()) throw new Exception("Environment variable ANDROID_HOME is not pointing to a directory")
+	return androidHome
+}

build-logic/src/main/groovy/org.igniterealtime.smack.java-common-conventions.gradle

@@ -0,0 +1,373 @@
+plugins {
+	id 'biz.aQute.bnd.builder'
+	id 'checkstyle'
+	id 'com.github.kt3k.coveralls'
+	id 'eclipse'
+	id 'idea'
+	id 'jacoco'
+	id 'java'
+	id 'java-library'
+	id 'java-test-fixtures'
+	id 'maven-publish'
+	id 'net.ltgt.errorprone'
+	id 'signing'
+
+	id 'jacoco-report-aggregation'
+	id 'test-report-aggregation'
+
+	id 'org.igniterealtime.smack.global-conventions'
+	id 'org.igniterealtime.smack.javadoc-conventions'
+}
+
+version readVersionFile()
+
+ext {
+	isSnapshot = version.endsWith('-SNAPSHOT')
+	gitCommit = getGitCommit()
+	rootConfigDir = new File(rootDir, 'config')
+	sonatypeCredentialsAvailable = project.hasProperty('sonatypeUsername') && project.hasProperty('sonatypePassword')
+	isReleaseVersion = !isSnapshot
+	isContinuousIntegrationEnvironment = Boolean.parseBoolean(System.getenv('CI'))
+	signingRequired = !(isSnapshot || isContinuousIntegrationEnvironment)
+	sonatypeSnapshotUrl = 'https://oss.sonatype.org/content/repositories/snapshots'
+	sonatypeStagingUrl = 'https://oss.sonatype.org/service/local/staging/deploy/maven2'
+	builtDate = (new java.text.SimpleDateFormat("yyyy-MM-dd")).format(new Date())
+	oneLineDesc = 'An Open Source XMPP (Jabber) client library'
+
+	jxmppVersion = '[1.1.0-beta1, 1.1.999]'
+	miniDnsVersion = '[1.1.0-alpha3, 1.1.999]'
+	junitVersion = '5.9.2'
+	commonsIoVersion = '2.6'
+	bouncyCastleVersion = '1.73'
+	guavaVersion = '30.1-jre'
+	mockitoVersion = '5.13.0'
+	orgReflectionsVersion = '0.9.11'
+
+	if (project.hasProperty("useSonatype")) {
+		useSonatype = project.getProperty("useSonatype").toBoolean()
+	} else {
+		// Default to true
+		useSonatype = true
+	}
+
+	gplLicensedProjects = [
+			':smack-examples',
+			':smack-omemo-signal',
+			':smack-omemo-signal-integration-test',
+			':smack-repl'
+		].collect{ project(it) }
+}
+
+group = 'org.igniterealtime.smack'
+
+java {
+	sourceCompatibility = javaVersion
+	targetCompatibility = sourceCompatibility
+}
+
+eclipse {
+	classpath {
+		downloadJavadoc = true
+	}
+}
+
+// Make all project's 'test' target depend on javadoc, so that
+// javadoc is also linted.
+test.dependsOn javadoc
+
+tasks.withType(JavaCompile) {
+	// Some systems may not have set their platform default
+	// converter to 'utf8', but we use unicode in our source
+	// files. Therefore ensure that javac uses unicode
+	options.encoding = "utf8"
+	options.compilerArgs = [
+		'-Xlint:all',
+		// Set '-options' because a non-java7 javac will emit a
+		// warning if source/target is set to 1.7 and
+		// bootclasspath is *not* set.
+		'-Xlint:-options',
+		// TODO: Enable xlint serial
+		'-Xlint:-serial',
+		'-Werror',
+	]
+}
+if (JavaVersion.current().isJava8Compatible()) {
+	tasks.withType(Javadoc) {
+		// The '-quiet' as second argument is actually a hack,
+		// since the one parameter addStringOption doesn't seem to
+		// work, we extra add '-quiet', which is added anyway by
+		// gradle.
+		// We disable 'missing' as we do most of javadoc checking via checkstyle.
+		options.addStringOption('Xdoclint:all,-missing', '-quiet')
+		// Abort on javadoc warnings.
+		// See JDK-8200363 (https://bugs.openjdk.java.net/browse/JDK-8200363)
+		// for information about the -Xwerror option.
+		options.addStringOption('Xwerror', '-quiet')
+	}
+}
+
+if (JavaVersion.current().isJava9Compatible()) {
+	tasks.withType(JavaCompile) {
+		options.compilerArgs.addAll([
+			'--release', javaMajor,
+		])
+	}
+}
+
+jacoco {
+	toolVersion = "0.8.12"
+}
+
+jacocoTestReport {
+	dependsOn test
+	reports {
+		xml.required = true
+	}
+}
+
+dependencies {
+	testImplementation "org.junit.jupiter:junit-jupiter-api:$junitVersion"
+	testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$junitVersion"
+
+	testFixturesApi "org.junit.jupiter:junit-jupiter-api:$junitVersion"
+	testImplementation "org.junit.jupiter:junit-jupiter-params:$junitVersion"
+	testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$junitVersion"
+	// https://stackoverflow.com/a/77274251/194894
+	testRuntimeOnly "org.junit.platform:junit-platform-launcher:1.11.0"
+
+	// The smack-extensions subproject uses mockito in its fest
+	// fixtures, and we want to have mockito also available in
+	// test, so we use API here.
+	testFixturesApi "org.mockito:mockito-core:${mockitoVersion}"
+
+	testImplementation 'com.jamesmurty.utils:java-xmlbuilder:1.2'
+
+	errorprone 'com.google.errorprone:error_prone_core:2.9.0'
+	errorproneJavac('com.google.errorprone:javac:9+181-r4173-1')
+}
+
+test {
+	useJUnitPlatform()
+
+	maxParallelForks = Runtime.runtime.availableProcessors().intdiv(2) ?: 1
+
+	// Enable full stacktraces of failed tests. Especially handy
+	// for CI environments.
+	testLogging {
+		events "failed"
+		exceptionFormat "full"
+	}
+}
+
+jar {
+	manifest {
+		attributes(
+			'Implementation-Version': version,
+			'Implementation-GitRevision': gitCommit,
+			'Built-JDK': System.getProperty('java.version'),
+			'Built-Gradle': gradle.gradleVersion,
+			'Built-By': System.getProperty('user.name')
+		)
+	}
+
+	bundle {
+		bnd(
+				'-removeheaders': 'Tool, Bnd-*',
+				'-exportcontents': '*',
+		)
+	}
+}
+
+checkstyle {
+	toolVersion = '8.27'
+
+	if (project in gplLicensedProjects) {
+		configProperties.checkstyleLicenseHeader = "${project.name}-gplv3-license-header"
+	} else {
+		configProperties.checkstyleLicenseHeader = "header"
+	}
+}
+task sourcesJar(type: Jar, dependsOn: classes) {
+	archiveClassifier = 'sources'
+	from sourceSets.main.allSource
+}
+task javadocJar(type: Jar, dependsOn: javadoc) {
+	archiveClassifier = 'javadoc'
+	from javadoc.destinationDir
+}
+task testsJar(type: Jar) {
+	archiveClassifier = 'tests'
+	from sourceSets.test.output
+}
+configurations {
+	testRuntime
+}
+artifacts {
+	// Add a 'testRuntime' configuration including the tests so that
+	// it can be consumed by other projects (smack-omemo-signal for
+	// example).  See http://stackoverflow.com/a/21946676/194894
+	testRuntime testsJar
+}
+
+publishing {
+	publications {
+		mavenJava(MavenPublication) {
+			from components.java
+			artifact sourcesJar
+			artifact javadocJar
+			artifact testsJar
+			pom {
+				name = 'Smack'
+				packaging = 'jar'
+				inceptionYear = '2003'
+				url = 'http://www.igniterealtime.org/projects/jxmpp/'
+				afterEvaluate {
+					description = project.description
+				}
+
+				issueManagement {
+					system = 'JIRA'
+					url = 'http://issues.igniterealtime.org/browse/SMACK'
+				}
+
+				scm {
+					url = 'https://github.com/igniterealtime/Smack'
+					connection = 'scm:git:https://github.com/igniterealtime/Smack.git'
+					developerConnection = 'scm:git:https://github.com/igniterealtime/Smack.git'
+				}
+
+				licenses {
+					if (project in gplLicensedProjects) {
+						license {
+							name = 'GNU General Public License, version 3 or any later version'
+							url = 'https://www.gnu.org/licenses/gpl.txt'
+							distribution = 'repo'
+						}
+					} else {
+						license {
+							name = 'The Apache Software License, Version 2.0'
+							url = 'http://www.apache.org/licenses/LICENSE-2.0.txt'
+							distribution = 'repo'
+						}
+					}
+				}
+
+				developers {
+					developer {
+						id = 'flow'
+						name = 'Florian Schmaus'
+						email = 'flow@igniterealtime.org'
+					}
+				}
+			}
+		}
+	}
+	repositories {
+		if (sonatypeCredentialsAvailable && useSonatype) {
+			maven {
+				url isSnapshot ? sonatypeSnapshotUrl : sonatypeStagingUrl
+				credentials {
+					username = sonatypeUsername
+					password = sonatypePassword
+				}
+			}
+		}
+		// Use
+		// gradle publish -P customRepoUrl=https://www.igniterealtime.org/archiva/repository/maven -P customRepoUsername=bamboo -P customRepoPassword=hidden -P useSonatype=false
+		// to deploy to this repo.
+		if (project.hasProperty("customRepoUrl")) {
+			maven {
+				name 'customRepo'
+				url customRepoUrl
+				if (project.hasProperty("customRepoUsername")) {
+					credentials {
+						username customRepoUsername
+						password customRepoPassword
+					}
+				}
+			}
+		}
+	}
+}
+
+// Workaround for gpg signatory not supporting the 'required' option
+// See https://github.com/gradle/gradle/issues/5064#issuecomment-381924984
+// Note what we use 'signing.gnupg.keyName' instead of 'signing.keyId'.
+tasks.withType(Sign) {
+	onlyIf {
+		project.hasProperty('signing.gnupg.keyName')
+	}
+}
+signing {
+	required { signingRequired }
+	useGpgCmd()
+	sign publishing.publications.mavenJava
+}
+
+tasks.withType(JavaCompile) {
+	options.errorprone {
+		disableWarningsInGeneratedCode = true
+		excludedPaths = ".*/jmh_generated/.*"
+		error(
+			"UnusedVariable",
+			"UnusedMethod",
+			"MethodCanBeStatic",
+		)
+		errorproneArgs = [
+			// Disable MissingCasesInEnumSwitch error prone check
+			// because this check is already done by javac as incomplete-switch.
+			'-Xep:MissingCasesInEnumSwitch:OFF',
+			'-Xep:StringSplitter:OFF',
+			'-Xep:JavaTimeDefaultTimeZone:OFF',
+			'-Xep:InlineMeSuggester:OFF',
+		]
+	}
+}
+
+// Work around https://github.com/gradle/gradle/issues/4046
+task copyJavadocDocFiles(type: Copy) {
+	from('src/javadoc')
+	into 'build/docs/javadoc'
+	include '**/doc-files/*.*'
+}
+javadoc.dependsOn copyJavadocDocFiles
+
+coveralls {
+	jacocoReportPath 'build/reports/jacoco/testCodeCoverageReport/testCodeCoverageReport.xml'
+}
+
+def getGitCommit() {
+	def projectDirFile = new File("$projectDir")
+
+	def cmd = 'git describe --always --tags --dirty=+'
+	def proc = cmd.execute(null, projectDirFile)
+
+	def exitStatus = proc.waitFor()
+	if (exitStatus != 0) return "non-git build"
+
+	def gitCommit = proc.text.trim()
+	assert !gitCommit.isEmpty()
+	gitCommit
+}
+
+def getAndroidRuntimeJar() {
+	def androidHome = new File("$System.env.ANDROID_HOME")
+	if (!androidHome.isDirectory()) throw new Exception("ANDROID_HOME not found or set")
+	def androidJar = new File("$androidHome/platforms/android-$smackMinAndroidSdk/android.jar")
+	if (androidJar.isFile()) {
+		return androidJar
+	} else {
+		throw new Exception("Can't find android.jar for $smackMinAndroidSdk API. Please install corresponding SDK platform package")
+	}
+}
+
+def readVersionFile() {
+	def versionFile = new File(rootDir, 'version')
+	if (!versionFile.isFile()) {
+		throw new Exception("Could not find version file")
+	}
+	if (versionFile.text.isEmpty()) {
+		throw new Exception("Version file does not contain a version")
+	}
+	versionFile.text.trim()
+}

build-logic/src/main/groovy/org.igniterealtime.smack.javadoc-conventions.gradle

@@ -0,0 +1,30 @@
+plugins {
+	// Javadoc linking requires repositories to bet configured. And
+	// those are declared in global-conventions, hence we add it here.
+	id 'org.igniterealtime.smack.global-conventions'
+}
+
+if (JavaVersion.current().isJava8Compatible()) {
+	tasks.withType(Javadoc) {
+		// The '-quiet' as second argument is actually a hack,
+		// since the one parameter addStringOption doesn't seem to
+		// work, we extra add '-quiet', which is added anyway by
+		// gradle.
+		// We disable 'missing' as we do most of javadoc checking via checkstyle.
+		options.addStringOption('Xdoclint:all,-missing', '-quiet')
+		// Abort on javadoc warnings.
+		// See JDK-8200363 (https://bugs.openjdk.java.net/browse/JDK-8200363)
+		// for information about the -Xwerror option.
+		options.addStringOption('Xwerror', '-quiet')
+	}
+}
+
+if (JavaVersion.current().isJava9Compatible()) {
+	tasks.withType(Javadoc) {
+		options.addStringOption('-release', javaMajor)
+	}
+}
+
+tasks.withType(Javadoc) {
+	options.charSet = "UTF-8"
+}