Restore JDK 8 runtime compatibility, fixes #888 #845

	#
	# Licensed to the Apache Software Foundation (ASF) under one or more
	# contributor license agreements. See the NOTICE file distributed with
	# this work for additional information regarding copyright ownership.
	# The ASF licenses this file to You under the Apache License, Version 2.0
	# (the "License"); you may not use this file except in compliance with
	# the License. You may obtain a copy of the License at
	#
	# http://www.apache.org/licenses/LICENSE-2.0
	#
	# Unless required by applicable law or agreed to in writing, software
	# distributed under the License is distributed on an "AS IS" BASIS,
	# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	# See the License for the specific language governing permissions and
	# limitations under the License.
	#

	name: build

	on:
	push:
	branches:
	- master
	pull_request:
	branches:
	- master

	jobs:
	compile:
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	os: [ ubuntu-latest, windows-latest, macos-latest ]
	java: [ '21' ]
	steps:
	- uses: actions/checkout@v2

	- name: Set up JDK ${{ matrix.java }}
	uses: actions/setup-java@v1
	with:
	java-version: ${{ matrix.java }}

	- uses: actions/cache@v1
	with:
	path: ~/.m2/repository
	key: ${{ matrix.os }}-maven-${{ hashFiles('**/pom.xml') }}
	restore-keys: \|
	${{ matrix.os }}-maven-

	- name: Build with maven
	run: mvn --no-transfer-progress verify

Provide feedback