Add a way to run a test only with a certain Java version

Closes gh-9530

spring-boot-test/src/main/java/org/springframework/boot/test/Assume.java

+/*
+ * Copyright 2012-2017 the original author or authors.
+ *
+ * Licensed 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.
+ */
+
+package org.springframework.boot.test;
+
+import org.junit.AssumptionViolatedException;
+
+import org.springframework.boot.system.JavaVersion;
+
+/**
+ * Provides utility methods that allow JUnit tests to {@link org.junit.Assume} certain
+ * conditions hold {@code true}. If the assumption fails, it means the test should be
+ * skipped.
+ *
+ * @author Stephane Nicoll
+ * @since 2.0.0
+ */
+public abstract class Assume {
+
+	/**
+	 * Assume that the specified {@link JavaVersion} is the one currently available.
+	 * @param version the expected Java version
+	 * @throws AssumptionViolatedException if the assumption fails
+	 */
+	public static void javaVersion(JavaVersion version) {
+		JavaVersion currentVersion = JavaVersion.getJavaVersion();
+		boolean outcome = currentVersion.compareTo(JavaVersion.NINE) < 0;
+		org.junit.Assume.assumeTrue(String.format(
+				"This test should run on %s (got %s)", version, currentVersion), outcome);
+	}
+
+}