feat(Maven): Filter out Tycho definition files in Maven

Implement the `mapDefinitionFiles()` function in `Maven` to exclude
all definition files belonging to Tycho projects. The upcoming Tycho
implementation needs to handle then the projects that are filtered out
here.

Signed-off-by: Oliver Heger <oliver.heger@bosch.io>

Author: oheger-bosch

plugins/package-managers/maven/src/main/kotlin/Maven.kt

@@ -42,6 +42,7 @@ import org.ossreviewtoolkit.plugins.packagemanagers.maven.utils.LocalProjectWork
 import org.ossreviewtoolkit.plugins.packagemanagers.maven.utils.MavenDependencyHandler
 import org.ossreviewtoolkit.plugins.packagemanagers.maven.utils.MavenSupport
 import org.ossreviewtoolkit.plugins.packagemanagers.maven.utils.getOriginalScm
+import org.ossreviewtoolkit.plugins.packagemanagers.maven.utils.isTychoProject
 import org.ossreviewtoolkit.plugins.packagemanagers.maven.utils.parseAuthors
 import org.ossreviewtoolkit.plugins.packagemanagers.maven.utils.parseLicenses
 import org.ossreviewtoolkit.plugins.packagemanagers.maven.utils.parseVcsInfo
@@ -91,6 +92,19 @@ class Maven(
         graphBuilder = DependencyGraphBuilder(dependencyHandler)
     }
 
+    /**
+     * Map the given [definitionFiles] to a list of files that should be processed. This implementation filters out
+     * projects that require the Tycho build extension.
+     */
+    override fun mapDefinitionFiles(definitionFiles: List<File>): List<File> {
+        val tychoRoots = definitionFiles.filter(::isTychoProject).map { it.parentFile }
+
+        // All pom files under a Tycho project will be handled by Tycho and therefore need to be excluded.
+        return definitionFiles.filterNot { file ->
+            tychoRoots.any { file.startsWith(it) }
+        }
+    }
+
     override fun createPackageManagerResult(projectResults: Map<File, List<ProjectAnalyzerResult>>) =
         PackageManagerResult(projectResults, graphBuilder.build(), graphBuilder.packages())
 

plugins/package-managers/maven/src/test/kotlin/MavenTest.kt

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2025 The ORT Project Authors (see <https://github.com/oss-review-toolkit/ort/blob/main/NOTICE>)
+ *
+ * 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
+ *
+ *     https://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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * License-Filename: LICENSE
+ */
+
+package org.ossreviewtoolkit.plugins.packagemanagers.maven
+
+import io.kotest.core.spec.style.WordSpec
+import io.kotest.engine.spec.tempdir
+import io.kotest.matchers.collections.shouldContainExactlyInAnyOrder
+
+import io.mockk.mockk
+
+class MavenTest : WordSpec({
+    "mapDefinitionFiles()" should {
+        "filter out Tycho definition files" {
+            val tychoProjectDir1 = tempdir()
+            tychoProjectDir1.addTychoExtension()
+            val tychoDefinitionFile1 = tychoProjectDir1.resolve("pom.xml").also { it.writeText("pom-tycho1") }
+            val tychoSubProjectDir = tychoProjectDir1.resolve("subproject")
+            val tychoSubModule = tychoSubProjectDir.resolve("pom.xml")
+            val tychoProjectDir2 = tempdir()
+            tychoProjectDir2.addTychoExtension()
+            val tychoDefinitionFile2 = tychoProjectDir2.resolve("pom.xml").also { it.writeText("pom-tycho2") }
+
+            val mavenProjectDir = tempdir()
+            val mavenDefinitionFile = mavenProjectDir.resolve("pom.xml").also { it.writeText("pom-maven") }
+            val mavenSubProjectDir = mavenProjectDir.resolve("subproject")
+            val mavenSubModule = mavenSubProjectDir.resolve("pom.xml")
+
+            val definitionFiles = listOf(
+                tychoDefinitionFile1,
+                mavenDefinitionFile,
+                tychoDefinitionFile2,
+                mavenSubModule,
+                tychoSubModule
+            )
+
+            val maven = Maven("Maven", tempdir(), mockk(relaxed = true), mockk(relaxed = true))
+            val mappedDefinitionFiles = maven.mapDefinitionFiles(definitionFiles)
+
+            mappedDefinitionFiles shouldContainExactlyInAnyOrder listOf(mavenDefinitionFile, mavenSubModule)
+        }
+    }
+})