#530: Use java.version property from parent pom if available (#593)

* #530: Use `java.version` property from parent pom if available

* Fix sonar warning

* Implement review finding

doc/changes/changes_4.3.4.md

@@ -19,6 +19,7 @@ The release also pins Maven plugin versions to avoid plugin versions depending o
 ### Bugfixes
 
 * #585: Pinned Maven plugin versions in generated parent pom
+* #530: Omit `java.version` property when pom has a parent
 
 ### Documentation
 

maven-project-crawler/pom.xml

@@ -11,10 +11,6 @@
         <artifactId>project-keeper-java-project-crawler-generated-parent</artifactId>
         <version>${revision}</version>
     </parent>
-    <properties>
-        <!-- Workaround for https://github.com/exasol/project-keeper/issues/530 -->
-        <java.version>17</java.version>
-    </properties>
     <prerequisites>
         <maven>${minimum.maven.version}</maven>
     </prerequisites>

project-keeper-cli/pom.xml

@@ -11,10 +11,6 @@
         <artifactId>project-keeper-cli-generated-parent</artifactId>
         <version>${revision}</version>
     </parent>
-    <properties>
-        <!-- Workaround for https://github.com/exasol/project-keeper/issues/530 -->
-        <java.version>17</java.version>
-    </properties>
     <dependencies>
         <dependency>
             <groupId>com.exasol</groupId>

project-keeper-maven-plugin/pom.xml

@@ -12,10 +12,6 @@
         <artifactId>project-keeper-maven-plugin-generated-parent</artifactId>
         <version>${revision}</version>
     </parent>
-    <properties>
-        <!-- Workaround for https://github.com/exasol/project-keeper/issues/530 -->
-        <java.version>17</java.version>
-    </properties>
     <prerequisites>
         <maven>${minimum.maven.version}</maven>
     </prerequisites>

project-keeper/pom.xml

@@ -12,10 +12,6 @@
         <artifactId>project-keeper-core-generated-parent</artifactId>
         <version>${revision}</version>
     </parent>
-    <properties>
-        <!-- Workaround for https://github.com/exasol/project-keeper/issues/530 -->
-        <java.version>17</java.version>
-    </properties>
     <dependencies>
         <dependency>
             <groupId>com.exasol</groupId>

project-keeper/src/main/java/com/exasol/projectkeeper/validators/pom/PomFileGenerator.java

@@ -101,7 +101,7 @@ private NodeBuilder projectBuilder(final Config config) {
                 .child(VERSION, config.getVersion()) //
                 .child("packaging", "pom") //
                 .nullableChild(parentReference(parentPomRef)) //
-                .child(properties(modules)) //
+                .child(properties(modules, parentPomRef == null ? DEFAULT_JAVA_VERSION : null)) //
                 .nullableChild(profiles(modules)) //
                 .nullableChild(distributionManagement(modules)) //
                 .child(licenses(config)) //
@@ -207,11 +207,11 @@ private ElementBuilder build(final Collection<ProjectKeeperModule> enabledModule
         return element("build").child(plugins(enabledModules));
     }
 
-    private ElementBuilder properties(final Collection<ProjectKeeperModule> enabledModules) {
+    private ElementBuilder properties(final Collection<ProjectKeeperModule> enabledModules, final String javaVersion) {
         return element("properties") //
                 .child("project.build.sourceEncoding", "UTF-8") //
                 .child("project.reporting.outputEncoding", "UTF-8") //
-                .child("java.version", DEFAULT_JAVA_VERSION) //
+                .nullableChild(javaVersion == null ? null : element("java.version").text(javaVersion)) //
                 .child("sonar.organization", "exasol") //
                 .child("sonar.host.url", "https://sonarcloud.io") //
                 .child("test.excludeTags", "") //

project-keeper/src/test/java/com/exasol/projectkeeper/validators/pom/PomFileGeneratorTest.java

@@ -1,5 +1,6 @@
 package com.exasol.projectkeeper.validators.pom;
 
+import static java.util.Collections.emptyList;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.*;
 import static org.junit.jupiter.api.Assertions.assertAll;
@@ -44,7 +45,7 @@ private List<String> getDependencyNames(final Model pom) {
 
     // [utest -> dsn~mvn-toolchain~1]
     @Test
-    void testGenerateWithDefaultModule() throws XmlPullParserException, IOException {
+    void testGenerateWithDefaultModule() {
         final Model pom = runGeneration(List.of(ProjectKeeperModule.DEFAULT), null);
         final List<String> pluginNames = getPluginNames(pom);
         final License license = pom.getLicenses().get(0);
@@ -88,7 +89,7 @@ static Stream<Arguments> testPluginsAddedByModuleCases() {
     }
 
     @Test
-    void testProfilesForNativeImages() throws XmlPullParserException, IOException {
+    void testProfilesForNativeImages() {
         final Model pom = runGeneration(List.of(ProjectKeeperModule.NATIVE_IMAGE), null);
         final List<Profile> profiles = pom.getProfiles();
         final Profile profile1 = profiles.get(0);
@@ -100,13 +101,26 @@ void testProfilesForNativeImages() throws XmlPullParserException, IOException {
         );
     }
 
-    private Model runGeneration(final List<ProjectKeeperModule> modules, final ParentPomRef parentPomRef)
-            throws IOException, XmlPullParserException {
+    @Test
+    void testAddJavaVersionPropertyForRootPom() {
+        final Model pom = runGeneration(emptyList(), null);
+        assertThat(pom.getProperties().get("java.version"), equalTo(PomFileGenerator.DEFAULT_JAVA_VERSION));
+    }
+
+    @Test
+    void testOmitJavaVersionPropertyForNonRootPom() {
+        final Model pom = runGeneration(emptyList(), new ParentPomRef("group", "parent-artifact", "version", "path"));
+        assertThat(pom.getProperties().get("java.version"), nullValue());
+    }
+
+    private Model runGeneration(final List<ProjectKeeperModule> modules, final ParentPomRef parentPomRef) {
         final String result = new PomFileGenerator().generatePomContent(modules, "com.example", "my-parent-pom",
                 "1.0.0", parentPomRef, new RepoInfo(TEST_REPO_NAME, TEST_REPO_LICENSE));
         try (final ByteArrayInputStream inputStream = new ByteArrayInputStream(
                 result.getBytes(StandardCharsets.UTF_8))) {
             return new MavenXpp3Reader().read(inputStream);
+        } catch (IOException | XmlPullParserException exception) {
+            throw new IllegalStateException("Failed to generate POM file: " + exception.getMessage(), exception);
         }
     }
 
@@ -119,31 +133,28 @@ static Stream<Arguments> testDependenciesAddedByModuleCases() {
 
     @ParameterizedTest
     @ValueSource(booleans = { true, false })
-    void distributionManagement(final boolean hasDm) throws IOException, XmlPullParserException {
+    void distributionManagement(final boolean hasDm) {
         final Model pom = runGeneration(hasDm ? List.of(ProjectKeeperModule.MAVEN_CENTRAL) : List.of(), null);
         assertThat(pom.getDistributionManagement(), hasDm ? not(nullValue()) : nullValue());
     }
 
     @ParameterizedTest
     @MethodSource("testPluginsAddedByModuleCases")
-    void testPluginsAddedByModule(final ProjectKeeperModule module, final List<String> expectedPlugins)
-            throws XmlPullParserException, IOException {
+    void testPluginsAddedByModule(final ProjectKeeperModule module, final List<String> expectedPlugins) {
         final Model pom = runGeneration(List.of(module), null);
         assertThat(getPluginNames(pom), hasItems(expectedPlugins.toArray(String[]::new)));
     }
 
     @ParameterizedTest
     @MethodSource("testDependenciesAddedByModuleCases")
-    void testDependenciesAddedByModule(final ProjectKeeperModule module, final List<String> expectedDependencies)
-            throws XmlPullParserException, IOException {
+    void testDependenciesAddedByModule(final ProjectKeeperModule module, final List<String> expectedDependencies) {
         final Model pom = runGeneration(List.of(module), null);
         assertThat(getDependencyNames(pom), hasItems(expectedDependencies.toArray(String[]::new)));
     }
 
     @ParameterizedTest
     @MethodSource("testGenerationWithParentPomCases")
-    void testGenerationWithParentPom(final String relativePath, final String expectedRelativePath)
-            throws XmlPullParserException, IOException {
+    void testGenerationWithParentPom(final String relativePath, final String expectedRelativePath) {
         final Model pom = runGeneration(List.of(ProjectKeeperModule.DEFAULT),
                 new ParentPomRef("com.example", "my-parent", "1.2.3", relativePath));
         final Parent parent = pom.getParent();
@@ -156,7 +167,7 @@ void testGenerationWithParentPom(final String relativePath, final String expecte
     }
 
     @Test
-    void testReproducibleBuildPluginIsLast() throws XmlPullParserException, IOException {
+    void testReproducibleBuildPluginIsLast() {
         final Model pom = runGeneration(List.of(ProjectKeeperModule.DEFAULT), null);
         final List<Plugin> plugins = pom.getBuild().getPlugins();
         final Plugin lastPlugin = plugins.get(plugins.size() - 1);

shared-model-classes/pom.xml

@@ -10,10 +10,6 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>project-keeper-shared-model-classes</artifactId>
     <name>Project Keeper shared model classes</name>
-    <properties>
-        <!-- Workaround for https://github.com/exasol/project-keeper/issues/530 -->
-        <java.version>17</java.version>
-    </properties>
     <dependencies>
         <dependency>
             <groupId>jakarta.json</groupId>

shared-test-setup/pom.xml

@@ -12,8 +12,6 @@
         <version>${revision}</version>
     </parent>
     <properties>
-        <!-- Workaround for https://github.com/exasol/project-keeper/issues/530 -->
-        <java.version>17</java.version>
         <sonar.coverage.exclusions>**/*.*</sonar.coverage.exclusions>
     </properties>
     <dependencies>