Change the maven plugin to allow use a source with classifier.

spring-boot-tools/spring-boot-maven-plugin/src/it/jar-repackage-classifier/pom.xml

@@ -0,0 +1,66 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>jar-repackage-classifier</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-jar-plugin</artifactId>
+				<version>@maven-jar-plugin.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>jar</goal>
+						</goals>
+						<phase>package</phase>
+						<configuration>
+							<classifier>test</classifier>
+							<archive>
+								<manifestEntries>
+									<Not-Used>Foo</Not-Used>
+								</manifestEntries>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+						<configuration>
+							<classifier>test</classifier>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>javax.servlet</groupId>
+			<artifactId>javax.servlet-api</artifactId>
+			<version>@servlet-api.version@</version>
+			<scope>provided</scope>
+		</dependency>
+	</dependencies>
+</project>

spring-boot-tools/spring-boot-maven-plugin/src/it/jar-repackage-classifier/src/main/java/org/test/SampleApplication.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2012-2014 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.
+ * 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 org.test;
+
+public class SampleApplication {
+
+	public static void main(String[] args) {
+	}
+
+}

spring-boot-tools/spring-boot-maven-plugin/src/it/jar-repackage-classifier/verify.groovy

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2012-2014 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.
+ * 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.
+ */
+
+import java.io.*;
+import org.springframework.boot.maven.*;
+
+File f = new File(basedir, "target/jar-repackage-classifier-0.0.1.BUILD-SNAPSHOT-test.jar");
+new Verify.JarArchiveVerification(f, Verify.SAMPLE_APP) {
+	@Override
+	protected void verifyZipEntries(Verify.ArchiveVerifier verifier) throws Exception {
+		super.verifyZipEntries(verifier)
+	}
+}.verify();

spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/RepackageMojo.java

@@ -23,6 +23,7 @@
 import java.util.Properties;
 import java.util.Set;
 
+import org.apache.commons.io.FilenameUtils;
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.model.Dependency;
 import org.apache.maven.plugin.MojoExecutionException;
@@ -54,6 +55,7 @@
  * @author Phillip Webb
  * @author Dave Syer
  * @author Stephane Nicoll
+ * @author Björn Lindström
  */
 @Mojo(name = "repackage", defaultPhase = LifecyclePhase.PACKAGE, requiresProject = true, threadSafe = true, requiresDependencyResolution = ResolutionScope.COMPILE_PLUS_RUNTIME, requiresDependencyCollection = ResolutionScope.COMPILE_PLUS_RUNTIME)
 public class RepackageMojo extends AbstractDependencyFilterMojo {
@@ -96,7 +98,8 @@ public class RepackageMojo extends AbstractDependencyFilterMojo {
 	/**
 	 * Classifier to add to the artifact generated. If given, the artifact will be
 	 * attached with that classifier and the main artifact will be deployed as the main
-	 * artifact. If this is not given (default), it will replace the main artifact and
+	 * artifact. If an artifact with the classifier already exists, it will be used as source.
+	 * If a classifier is not given (default), it will replace the main artifact and
 	 * only the repackaged artifact will be deployed. Attaching the artifact allows to
 	 * deploy it alongside to the original one, see <a href=
 	 * "http://maven.apache.org/plugins/maven-deploy-plugin/examples/deploying-with-classifiers.html"
@@ -206,7 +209,7 @@ public void execute() throws MojoExecutionException, MojoFailureException {
 	}
 
 	private void repackage() throws MojoExecutionException {
-		File source = this.project.getArtifact().getFile();
+		File source = getSourceFile();
 		File target = getTargetFile();
 		Repackager repackager = getRepackager(source);
 		Set<Artifact> artifacts = filterDependencies(this.project.getArtifacts(),
@@ -223,18 +226,35 @@ private void repackage() throws MojoExecutionException {
 		updateArtifact(source, target, repackager.getBackupFile());
 	}
 
-	private File getTargetFile() {
-		String classifier = (this.classifier == null ? "" : this.classifier.trim());
-		if (classifier.length() > 0 && !classifier.startsWith("-")) {
-			classifier = "-" + classifier;
+	private File getSourceFile() {
+		File source = this.project.getArtifact().getFile();
+		if (this.classifier != null) {
+			File sourceWithClassifier = new File(source.getParent(),
+					FilenameUtils.getBaseName(source.getName()) + getClassifier() + "."
+							+ FilenameUtils.getExtension(source.getName()));
+			if (sourceWithClassifier.exists()) {
+				source = sourceWithClassifier;
+			}
 		}
+		return source;
+	}
+
+	private File getTargetFile() {
 		if (!this.outputDirectory.exists()) {
 			this.outputDirectory.mkdirs();
 		}
-		return new File(this.outputDirectory, this.finalName + classifier + "."
+		return new File(this.outputDirectory, this.finalName + getClassifier() + "."
 				+ this.project.getArtifact().getArtifactHandler().getExtension());
 	}
 
+	private String getClassifier() {
+		String classifier = (this.classifier == null ? "" : this.classifier.trim());
+		if (classifier.length() > 0 && !classifier.startsWith("-")) {
+			classifier = "-" + classifier;
+		}
+		return classifier;
+	}
+
 	private Repackager getRepackager(File source) {
 		Repackager repackager = new Repackager(source, this.layoutFactory);
 		repackager.addMainClassTimeoutWarningListener(