Feature maven expand wildcard import

plugin-maven/CHANGES.md

@@ -7,6 +7,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 - `<scalafmt>` now reads the version from the `version` field in the scalafmt config file when no `<version>` is explicitly set, falling back to the built-in default only if neither is available. ([#2922](https://github.com/diffplug/spotless/pull/2922))
 - Add `<toml>` format type with `<versionCatalog>` step for formatting and sorting Gradle version catalog files. ([#2916](https://github.com/diffplug/spotless/issues/2916))
 - Add `<javaparserVersion>` option to `<cleanthat>`, allowing users to override the JavaParser version pulled in transitively by Cleanthat. ([#2903](https://github.com/diffplug/spotless/pull/2903))
+- Add a `expandWildcardImports` API for java ([#2829](https://github.com/diffplug/spotless/pull/2930))
 ### Fixed
 - Preserve case of JDBI named bind params that collide with SQL keywords (e.g. `:limit`, `:offset`) in the DBeaver SQL formatter. ([#2899](https://github.com/diffplug/spotless/pull/2899))
 - The `-Dspotless.ratchetFrom=...` user property now takes priority over `<ratchetFrom>` configured in the plugin or in individual formatters, instead of being overridden by them. ([#2896](https://github.com/diffplug/spotless/pull/2896), fixes [#2842](https://github.com/diffplug/spotless/issues/2842))

plugin-maven/src/main/java/com/diffplug/spotless/maven/AbstractSpotlessMojo.java

@@ -27,6 +27,7 @@
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -412,7 +413,36 @@ private FormatterConfig getFormatterConfig() {
 		final Optional<String> userRatchetFrom = Optional.ofNullable((String) mavenSession.getUserProperties().get("ratchetFrom"));
 		final Optional<String> optionalRatchetFrom = Optional.ofNullable(this.ratchetFrom)
 				.filter(ratchet -> !RATCHETFROM_NONE.equals(ratchet));
-		return new FormatterConfig(baseDir, encoding, lineEndings, userRatchetFrom, optionalRatchetFrom, provisioner, p2Provisioner, fileLocator, formatterStepFactories, Optional.ofNullable(setLicenseHeaderYearsFromGitHistory), lintSuppressions);
+		Optional<Set<File>> projectClasspath = computeTypeSolverClasspath(resolver);
+		return new FormatterConfig(baseDir, encoding, lineEndings, userRatchetFrom, optionalRatchetFrom, provisioner, p2Provisioner, fileLocator, formatterStepFactories, Optional.ofNullable(setLicenseHeaderYearsFromGitHistory), lintSuppressions, projectClasspath);
+	}
+
+	private Optional<Set<File>> computeTypeSolverClasspath(ArtifactResolver resolver) {
+		Set<File> classpath = new LinkedHashSet<>();
+
+		// Add source roots (directories containing .java files for JavaParserTypeSolver)
+		for (String sourceRoot : project.getCompileSourceRoots()) {
+			File dir = new File(sourceRoot);
+			if (dir.exists()) {
+				classpath.add(dir);
+			}
+		}
+		for (String sourceRoot : project.getTestCompileSourceRoots()) {
+			File dir = new File(sourceRoot);
+			if (dir.exists()) {
+				classpath.add(dir);
+			}
+		}
+
+		// Resolve dependency JARs via RepositorySystem (for JarTypeSolver)
+		try {
+			Set<File> dependencyJars = resolver.resolveProjectDependencies(project, repositories);
+			classpath.addAll(dependencyJars);
+		} catch (Exception e) {
+			getLog().warn("Could not resolve project dependencies for expandWildcardImports: " + e.getMessage());
+		}
+
+		return Optional.of(classpath);
 	}
 
 	private FileLocator getFileLocator() {

plugin-maven/src/main/java/com/diffplug/spotless/maven/ArtifactResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2025 DiffPlug
+ * Copyright 2016-2026 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,11 +21,13 @@
 import java.io.File;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 import java.util.Set;
 
 import org.apache.maven.plugin.logging.Log;
+import org.apache.maven.project.MavenProject;
 import org.eclipse.aether.RepositorySystem;
 import org.eclipse.aether.RepositorySystemSession;
 import org.eclipse.aether.artifact.Artifact;
@@ -89,6 +91,34 @@ private DependencyResult resolveDependencies(DependencyRequest dependencyRequest
 		}
 	}
 
+	/**
+	 * Resolves all dependencies (all scopes) of the given Maven project using the
+	 * specified artifact repositories. Returns the set of resolved JAR files.
+	 */
+	public Set<File> resolveProjectDependencies(MavenProject project, List<RemoteRepository> artifactRepositories) {
+		List<Dependency> dependencies = project.getDependencies().stream()
+				.map(d -> new Dependency(
+						new DefaultArtifact(d.getGroupId(), d.getArtifactId(), d.getClassifier(), d.getType(), d.getVersion()),
+						d.getScope()))
+				.collect(toList());
+
+		if (dependencies.isEmpty()) {
+			return Collections.emptySet();
+		}
+
+		CollectRequest collectRequest = new CollectRequest(dependencies, null, artifactRepositories);
+		DependencyRequest dependencyRequest = new DependencyRequest(collectRequest, null);
+		DependencyResult dependencyResult = resolveDependencies(dependencyRequest);
+
+		return dependencyResult.getArtifactResults()
+				.stream()
+				.map(ArtifactResult::getArtifact)
+				.filter(Objects::nonNull)
+				.map(Artifact::getFile)
+				.filter(Objects::nonNull)
+				.collect(toSet());
+	}
+
 	private void logResolved(ArtifactResult artifactResult) {
 		if (log.isDebugEnabled()) {
 			log.debug("Resolved artifact: " + artifactResult);

plugin-maven/src/main/java/com/diffplug/spotless/maven/FormatterConfig.java

@@ -20,6 +20,7 @@
 import java.io.File;
 import java.util.List;
 import java.util.Optional;
+import java.util.Set;
 
 import com.diffplug.spotless.LineEnding;
 import com.diffplug.spotless.LintSuppression;
@@ -38,9 +39,10 @@ public class FormatterConfig {
 	private final List<FormatterStepFactory> globalStepFactories;
 	private final Optional<String> spotlessSetLicenseHeaderYearsFromGitHistory;
 	private final List<LintSuppression> lintSuppressions;
+	private final Optional<Set<File>> projectClasspath;
 
 	public FormatterConfig(File baseDir, String encoding, LineEnding lineEndings, Optional<String> userRatchetFrom, Optional<String> ratchetFrom, Provisioner provisioner,
-			P2Provisioner p2Provisioner, FileLocator fileLocator, List<FormatterStepFactory> globalStepFactories, Optional<String> spotlessSetLicenseHeaderYearsFromGitHistory, List<LintSuppression> lintSuppressions) {
+			P2Provisioner p2Provisioner, FileLocator fileLocator, List<FormatterStepFactory> globalStepFactories, Optional<String> spotlessSetLicenseHeaderYearsFromGitHistory, List<LintSuppression> lintSuppressions, Optional<Set<File>> projectClasspath) {
 		this.encoding = encoding;
 		this.lineEndings = lineEndings;
 		this.userRatchetFrom = userRatchetFrom;
@@ -51,6 +53,7 @@ public FormatterConfig(File baseDir, String encoding, LineEnding lineEndings, Op
 		this.globalStepFactories = globalStepFactories;
 		this.spotlessSetLicenseHeaderYearsFromGitHistory = spotlessSetLicenseHeaderYearsFromGitHistory;
 		this.lintSuppressions = lintSuppressions;
+		this.projectClasspath = projectClasspath;
 	}
 
 	public String getEncoding() {
@@ -92,4 +95,8 @@ public FileLocator getFileLocator() {
 	public List<LintSuppression> getLintSuppressions() {
 		return unmodifiableList(lintSuppressions);
 	}
+
+	public Optional<Set<File>> getProjectClasspath() {
+		return projectClasspath;
+	}
 }

plugin-maven/src/main/java/com/diffplug/spotless/maven/FormatterFactory.java

@@ -187,7 +187,7 @@ private Optional<String> optionalRatchetFrom() {
 	}
 
 	private FormatterStepConfig stepConfig(Charset encoding, FormatterConfig config) {
-		return new FormatterStepConfig(encoding, licenseHeaderDelimiter(), ratchetFrom(config), config.getProvisioner(), config.getP2Provisioner(), config.getFileLocator(), config.getSpotlessSetLicenseHeaderYearsFromGitHistory());
+		return new FormatterStepConfig(encoding, licenseHeaderDelimiter(), ratchetFrom(config), config.getProvisioner(), config.getP2Provisioner(), config.getFileLocator(), config.getSpotlessSetLicenseHeaderYearsFromGitHistory(), config.getProjectClasspath());
 	}
 
 	private static List<FormatterStepFactory> gatherStepFactories(List<FormatterStepFactory> allGlobal, List<FormatterStepFactory> allConfigured) {

plugin-maven/src/main/java/com/diffplug/spotless/maven/FormatterStepConfig.java

@@ -15,8 +15,10 @@
  */
 package com.diffplug.spotless.maven;
 
+import java.io.File;
 import java.nio.charset.Charset;
 import java.util.Optional;
+import java.util.Set;
 
 import com.diffplug.spotless.Provisioner;
 import com.diffplug.spotless.extra.P2Provisioner;
@@ -30,15 +32,17 @@ public class FormatterStepConfig {
 	private final P2Provisioner p2Provisioner;
 	private final FileLocator fileLocator;
 	private final Optional<String> spotlessSetLicenseHeaderYearsFromGitHistory;
+	private final Optional<Set<File>> projectClasspath;
 
-	public FormatterStepConfig(Charset encoding, String licenseHeaderDelimiter, Optional<String> ratchetFrom, Provisioner provisioner, P2Provisioner p2Provisioner, FileLocator fileLocator, Optional<String> spotlessSetLicenseHeaderYearsFromGitHistory) {
+	public FormatterStepConfig(Charset encoding, String licenseHeaderDelimiter, Optional<String> ratchetFrom, Provisioner provisioner, P2Provisioner p2Provisioner, FileLocator fileLocator, Optional<String> spotlessSetLicenseHeaderYearsFromGitHistory, Optional<Set<File>> projectClasspath) {
 		this.encoding = encoding;
 		this.licenseHeaderDelimiter = licenseHeaderDelimiter;
 		this.ratchetFrom = ratchetFrom;
 		this.provisioner = provisioner;
 		this.p2Provisioner = p2Provisioner;
 		this.fileLocator = fileLocator;
 		this.spotlessSetLicenseHeaderYearsFromGitHistory = spotlessSetLicenseHeaderYearsFromGitHistory;
+		this.projectClasspath = projectClasspath;
 	}
 
 	public Charset getEncoding() {
@@ -68,4 +72,8 @@ public FileLocator getFileLocator() {
 	public Optional<String> spotlessSetLicenseHeaderYearsFromGitHistory() {
 		return spotlessSetLicenseHeaderYearsFromGitHistory;
 	}
+
+	public Optional<Set<File>> getProjectClasspath() {
+		return projectClasspath;
+	}
 }

plugin-maven/src/main/java/com/diffplug/spotless/maven/java/ExpandWildcardImports.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2025-2026 DiffPlug
+ *
+ * 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 com.diffplug.spotless.maven.java;
+
+import java.io.File;
+import java.util.Collections;
+import java.util.Set;
+
+import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.java.ExpandWildcardImportsStep;
+import com.diffplug.spotless.maven.FormatterStepConfig;
+import com.diffplug.spotless.maven.FormatterStepFactory;
+
+public class ExpandWildcardImports implements FormatterStepFactory {
+	@Override
+	public FormatterStep newFormatterStep(FormatterStepConfig config) {
+		Set<File> classpath = config.getProjectClasspath().orElse(Collections.emptySet());
+		return ExpandWildcardImportsStep.create(classpath, config.getProvisioner());
+	}
+}

plugin-maven/src/main/java/com/diffplug/spotless/maven/java/Java.java

@@ -79,6 +79,10 @@ public void addForbidWildcardImports(ForbidWildcardImports forbidWildcardImports
 		addStepFactory(forbidWildcardImports);
 	}
 
+	public void addExpandWildcardImports(ExpandWildcardImports expandWildcardImports) {
+		addStepFactory(expandWildcardImports);
+	}
+
 	public void addForbidModuleImports(ForbidModuleImports forbidModuleImports) {
 		addStepFactory(forbidModuleImports);
 	}

plugin-maven/src/test/java/com/diffplug/spotless/maven/java/ExpandWildcardImportsStepTest.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2025-2026 DiffPlug
+ *
+ * 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 com.diffplug.spotless.maven.java;
+
+import org.junit.jupiter.api.Test;
+
+import com.diffplug.spotless.maven.MavenIntegrationHarness;
+
+class ExpandWildcardImportsStepTest extends MavenIntegrationHarness {
+
+	@Test
+	void expandWildcardImports() throws Exception {
+		writePomWithJavaSteps("<expandWildcardImports/>");
+
+		// Create supporting classes in source roots so JavaParserTypeSolver can resolve them
+		setFile("src/main/java/foo/bar/AnotherClassInSamePackage.java")
+				.toResource("java/expandwildcardimports/AnotherClassInSamePackage.test");
+		setFile("src/main/java/foo/bar/baz/AnotherImportedClass.java")
+				.toResource("java/expandwildcardimports/AnotherImportedClass.test");
+		// Source for the annotation used in the test (resolves via source root, not JAR)
+		setFile("src/main/java/org/example/SomeAnnotation.java")
+				.toContent("package org.example;\n\npublic @interface SomeAnnotation {}\n");
+
+		String path = "src/main/java/foo/bar/JavaClassWithWildcards.java";
+		setFile(path).toResource("java/expandwildcardimports/JavaClassWithWildcardsUnformatted.test");
+
+		mavenRunner().withArguments("spotless:apply").runNoError();
+
+		assertFile(path).sameAsResource("java/expandwildcardimports/JavaClassWithWildcardsFormatted.test");
+	}
+}