Add support for Java 10

Closes gh-646

initializr-service/src/main/java/io/spring/initializr/service/extension/JavaVersionRequestPostProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -27,25 +27,29 @@ import io.spring.initializr.util.Version;
 import org.springframework.stereotype.Component;
 
 /**
- * Handle corner cases when Java9 is required.
+ * Validate that the requested java version is compatible with the chosen Spring Boot
+ * generation and adapt the request if necessary.
  *
  * @author Stephane Nicoll
  */
 @Component
-class Java9RequestPostProcessor implements ProjectRequestPostProcessor {
+class JavaVersionRequestPostProcessor implements ProjectRequestPostProcessor {
 
 	private static final Version VERSION_2_0_0_M1 = Version.parse("2.0.0.M1");
 
+	private static final Version VERSION_2_0_1 = Version.parse("2.0.1.RELEASE");
+
 	private static final List<String> UNSUPPORTED_LANGUAGES = Arrays.asList("groovy",
 			"kotlin");
 
 	@Override
 	public void postProcessAfterResolution(ProjectRequest request,
 			InitializrMetadata metadata) {
-		Version requestVersion = Version.safeParse(request.getBootVersion());
+		Integer javaGeneration = determineJavaGeneration(request.getJavaVersion());
-		if (!"9".equals(request.getJavaVersion())) {
+		if (javaGeneration == null) {
 			return;
 		}
+		Version requestVersion = Version.safeParse(request.getBootVersion());
 		// Not supported for Spring Boot 1.x
 		if (VERSION_2_0_0_M1.compareTo(requestVersion) > 0) {
 			request.setJavaVersion("1.8");
@@ -54,6 +58,20 @@ class Java9RequestPostProcessor implements ProjectRequestPostProcessor {
 		if (UNSUPPORTED_LANGUAGES.contains(request.getLanguage())) {
 			request.setJavaVersion("1.8");
 		}
+		// 10 support only as of 2.0.1
+		if (javaGeneration == 10 && VERSION_2_0_1.compareTo(requestVersion) > 0) {
+			request.setJavaVersion("1.8");
+		}
+	}
+
+	private Integer determineJavaGeneration(String javaVersion) {
+		try {
+			int generation = Integer.valueOf(javaVersion);
+			return ((generation > 8 && generation <=10)  ? generation : null);
+		}
+		catch (NumberFormatException e) {
+			return null;
+		}
 	}
 
 }

initializr-service/src/main/java/io/spring/initializr/service/extension/SpringBoot2RequestPostProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -36,7 +36,7 @@ class SpringBoot2RequestPostProcessor extends AbstractProjectRequestPostProcesso
 
 	private static final Version VERSION_2_0_0_M1 = Version.parse("2.0.0.M1");
 
-	private static final List<String> VALID_VERSIONS = Arrays.asList("1.8", "9");
+	private static final List<String> VALID_VERSIONS = Arrays.asList("1.8", "9", "10");
 
 	@Override
 	public void postProcessAfterResolution(ProjectRequest request,

initializr-service/src/main/resources/application.yml

@@ -1340,6 +1340,8 @@ initializr:
       id: war
       default: false
   javaVersions:
+    - id: 10
+      default: false
     - id: 9
       default: false
     - id: 1.8

initializr-service/src/test/java/io/spring/initializr/service/extension/JavaVersionRequestPostProcessorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -20,11 +20,11 @@ import io.spring.initializr.generator.ProjectRequest;
 import org.junit.Test;
 
 /**
- * Tests for {@link Java9RequestPostProcessor}.
+ * Tests for {@link JavaVersionRequestPostProcessor}.
  *
  * @author Stephane Nicoll
  */
-public class Java9RequestPostProcessorTests extends AbstractRequestPostProcessorTests {
+public class JavaVersionRequestPostProcessorTests extends AbstractRequestPostProcessorTests {
 
 	@Test
 	public void java9CannotBeUsedWithSpringBoot1Maven() {
@@ -94,4 +94,53 @@ public class Java9RequestPostProcessorTests extends AbstractRequestPostProcessor
 		generateGradleBuild(request).hasJavaVersion("9");
 	}
 
+	@Test
+	public void java10CannotBeUsedWithSpringBoot1Maven() {
+		ProjectRequest request = createProjectRequest("web");
+		request.setBootVersion("1.5.8.RELEASE");
+		request.setJavaVersion("10");
+		generateMavenPom(request).hasJavaVersion("1.8");
+	}
+
+	@Test
+	public void java10CannotBeUsedWithSpringBoot1Gradle() {
+		ProjectRequest request = createProjectRequest("data-jpa");
+		request.setBootVersion("1.99.99.BUILD-SNAPSHOT");
+		request.setJavaVersion("10");
+		generateGradleBuild(request).hasJavaVersion("1.8");
+	}
+
+	@Test
+	public void java10CannotBeUsedWithSpringBoot200Maven() {
+		ProjectRequest request = createProjectRequest("web");
+		request.setBootVersion("2.0.0.RELEASE");
+		request.setJavaVersion("10");
+		generateMavenPom(request).hasJavaVersion("1.8");
+	}
+
+	@Test
+	public void java10CannotBeUsedWithSpringBoot200Gradle() {
+		ProjectRequest request = createProjectRequest("data-jpa");
+		request.setBootVersion("2.0.0.RELEASE");
+		request.setJavaVersion("10");
+		generateGradleBuild(request).hasJavaVersion("1.8");
+	}
+
+
+	@Test
+	public void java10CanBeUsedWithSpringBoot2Maven() {
+		ProjectRequest request = createProjectRequest("web");
+		request.setBootVersion("2.0.1.RELEASE");
+		request.setJavaVersion("10");
+		generateMavenPom(request).hasJavaVersion("10");
+	}
+
+	@Test
+	public void java10CanBeUsedWithSpringBoot2Gradle() {
+		ProjectRequest request = createProjectRequest("data-jpa");
+		request.setBootVersion("2.0.2.RELEASE");
+		request.setJavaVersion("10");
+		generateGradleBuild(request).hasJavaVersion("10");
+	}
+
 }

initializr-service/src/test/java/io/spring/initializr/service/extension/SpringBoot2RequestPostProcessorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -59,4 +59,20 @@ public class SpringBoot2RequestPostProcessorTests
 		generateGradleBuild(request).hasJavaVersion("9");
 	}
 
+	@Test
+	public void java10CanBeUsedMaven() {
+		ProjectRequest request = createProjectRequest("web");
+		request.setBootVersion("2.1.0.BUILD-SNAPSHOT");
+		request.setJavaVersion("10");
+		generateMavenPom(request).hasJavaVersion("10");
+	}
+
+	@Test
+	public void java10CanBeUsedGradle() {
+		ProjectRequest request = createProjectRequest("data-jpa");
+		request.setBootVersion("2.0.2.RELEASE");
+		request.setJavaVersion("10");
+		generateGradleBuild(request).hasJavaVersion("10");
+	}
+
 }