Polish generated pom

This commit removes two useless properties that are already contributed
by `spring-boot-starter-parent`.

initializr-generator/src/main/java/io/spring/initializr/generator/ProjectGenerator.java

@@ -34,6 +34,7 @@ import java.util.stream.Collectors;
 import io.spring.initializr.InitializrException;
 import io.spring.initializr.metadata.BillOfMaterials;
 import io.spring.initializr.metadata.Dependency;
+import io.spring.initializr.metadata.InitializrConfiguration.Env.Maven;
 import io.spring.initializr.metadata.InitializrConfiguration.Env.Maven.ParentPom;
 import io.spring.initializr.metadata.InitializrMetadata;
 import io.spring.initializr.metadata.InitializrMetadataProvider;
@@ -364,14 +365,19 @@ public class ProjectGenerator {
 
 		if (isMavenBuild(request)) {
 			model.put("mavenBuild", true);
-			ParentPom parentPom = metadata.getConfiguration().getEnv().getMaven()
+			Maven maven = metadata.getConfiguration().getEnv().getMaven();
-					.resolveParentPom(request.getBootVersion());
+			ParentPom parentPom = maven.resolveParentPom(request.getBootVersion());
 			if (parentPom.isIncludeSpringBootBom()
 					&& !request.getBoms().containsKey("spring-boot")) {
 				request.getBoms().put("spring-boot", metadata.createSpringBootBom(
 						request.getBootVersion(), "spring-boot.version"));
 			}
-
+			if (!maven.isSpringBootStarterParent(parentPom)) {
+				request.getBuildProperties().getMaven()
+						.put("project.build.sourceEncoding", () -> "UTF-8");
+				request.getBuildProperties().getMaven()
+						.put("project.reporting.outputEncoding", () -> "UTF-8");
+			}
 			model.put("mavenParentGroupId", parentPom.getGroupId());
 			model.put("mavenParentArtifactId", parentPom.getArtifactId());
 			model.put("mavenParentVersion", parentPom.getVersion());

initializr-generator/src/main/java/io/spring/initializr/generator/ProjectRequest.java

@@ -239,10 +239,6 @@ public class ProjectRequest extends BasicProjectRequest {
 			}
 		}
 		else {
-			this.buildProperties.getMaven().put("project.build.sourceEncoding",
-					() -> "UTF-8");
-			this.buildProperties.getMaven().put("project.reporting.outputEncoding",
-					() -> "UTF-8");
 			this.buildProperties.getVersions().put(VersionProperty.of("java.version"),
 					this::getJavaVersion);
 			if ("kotlin".equals(getLanguage())) {

initializr-generator/src/main/java/io/spring/initializr/metadata/InitializrConfiguration.java

@@ -495,6 +495,10 @@ public class InitializrConfiguration {
 		 */
 		public static class Maven {
 
+			private static final String DEFAULT_PARENT_GROUP_ID = "org.springframework.boot";
+
+			private static final String DEFAULT_PARENT_ARTIFACT_ID = "spring-boot-starter-parent";
+
 			/**
 			 * Custom parent pom to use for generated projects.
 			 */
@@ -519,8 +523,20 @@ public class InitializrConfiguration {
 			 */
 			public ParentPom resolveParentPom(String bootVersion) {
 				return (StringUtils.hasText(this.parent.groupId) ? this.parent
-						: new ParentPom("org.springframework.boot",
+						: new ParentPom(DEFAULT_PARENT_GROUP_ID,
-								"spring-boot-starter-parent", bootVersion));
+								DEFAULT_PARENT_ARTIFACT_ID, bootVersion));
+			}
+
+			/**
+			 * Check if the specified {@link ParentPom} is the default spring boot starter
+			 * parent.
+			 * @param parentPom the parent pom to check
+			 * @return {@code true} if the {@code parentPom} is the spring boot starter
+			 * parent
+			 */
+			public boolean isSpringBootStarterParent(ParentPom parentPom) {
+				return DEFAULT_PARENT_GROUP_ID.equals(parentPom.getGroupId())
+						&& DEFAULT_PARENT_ARTIFACT_ID.equals(parentPom.getArtifactId());
 			}
 
 			/**

initializr-generator/src/test/java/io/spring/initializr/generator/ProjectGeneratorTests.java

@@ -384,7 +384,9 @@ public class ProjectGeneratorTests extends AbstractProjectGeneratorTests {
 	@Test
 	public void defaultMavenPomHasSpringBootParent() {
 		ProjectRequest request = createProjectRequest("web");
-		generateMavenPom(request).hasSpringBootParent(request.getBootVersion());
+		generateMavenPom(request).hasSpringBootParent(request.getBootVersion())
+				.hasNoProperty("project.build.sourceEncoding")
+				.hasNoProperty("project.reporting.outputEncoding");
 	}
 
 	@Test
@@ -395,7 +397,8 @@ public class ProjectGeneratorTests extends AbstractProjectGeneratorTests {
 		applyMetadata(metadata);
 		ProjectRequest request = createProjectRequest("web");
 		generateMavenPom(request).hasParent("com.foo", "foo-parent", "1.0.0-SNAPSHOT")
-				.hasBomsCount(0);
+				.hasBomsCount(0).hasProperty("project.build.sourceEncoding", "UTF-8")
+				.hasProperty("project.reporting.outputEncoding", "UTF-8");
 	}
 
 	@Test
@@ -410,7 +413,8 @@ public class ProjectGeneratorTests extends AbstractProjectGeneratorTests {
 				.hasProperty("spring-boot.version", "1.5.17.RELEASE")
 				.hasBom("org.springframework.boot", "spring-boot-dependencies",
 						"${spring-boot.version}")
-				.hasBomsCount(1);
+				.hasBomsCount(1).hasProperty("project.build.sourceEncoding", "UTF-8")
+				.hasProperty("project.reporting.outputEncoding", "UTF-8");
 	}
 
 	@Test

initializr-generator/src/test/resources/project/groovy/previous/pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 	</properties>
 

initializr-generator/src/test/resources/project/groovy/standard/pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 	</properties>
 

initializr-generator/src/test/resources/project/groovy/standard/war-pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 	</properties>
 

initializr-generator/src/test/resources/project/java/previous/pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 	</properties>
 

initializr-generator/src/test/resources/project/java/standard/pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 	</properties>
 

initializr-generator/src/test/resources/project/java/standard/war-pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 	</properties>
 

initializr-generator/src/test/resources/project/kotlin/previous/pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 		<kotlin.version>1.1.1</kotlin.version>
 	</properties>

initializr-generator/src/test/resources/project/kotlin/standard/pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 		<kotlin.version>1.1.1</kotlin.version>
 	</properties>

initializr-generator/src/test/resources/project/kotlin/standard/war-pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 		<kotlin.version>1.1.1</kotlin.version>
 	</properties>

initializr-generator/src/test/resources/project/maven/annotation-processor-dependency-pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 	</properties>
 

initializr-generator/src/test/resources/project/maven/bom-ordering-pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 	</properties>
 

initializr-generator/src/test/resources/project/maven/bom-property-pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<foo.version>1.3.3</foo.version>
 		<java.version>1.8</java.version>
 	</properties>

initializr-generator/src/test/resources/project/maven/compile-only-dependency-pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 	</properties>
 

initializr-generator/src/test/resources/project/maven/kotlin-java11-pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>11</java.version>
 		<kotlin.version>1.1.1</kotlin.version>
 	</properties>

initializr-generator/src/test/resources/project/maven/version-override-pom.xml.gen

@@ -16,8 +16,6 @@
 	<description>Demo project for Spring Boot</description>
 
 	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<java.version>1.8</java.version>
 		<spring-bar.version>0.2.0.RELEASE</spring-bar.version>
 		<spring-foo.version>0.1.0.RELEASE</spring-foo.version>