Support exclusion of optional dependencies in uber-jars

Update Maven plugin with `<includeOptional>` configuration property that
can be used to toggle if optional dependencies are packages.

For back-compatibility, in 3.5.x the default is `true`.

Fixes gh-25403

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/JarIntegrationTests.java

@@ -202,6 +202,42 @@ class JarIntegrationTests extends AbstractArchiveIntegrationTests {
 		});
 	}
 
+	@TestTemplate
+	void whenAnEntryIsOptionalByDefaultAppearsInTheRepackagedJar(MavenBuild mavenBuild) {
+		mavenBuild.project("jar-optional-default").goals("install").execute((project) -> {
+			File repackaged = new File(project, "target/jar-optional-default-0.0.1.BUILD-SNAPSHOT.jar");
+			assertThat(jar(repackaged)).hasEntryWithNameStartingWith("BOOT-INF/classes/")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-context")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-core")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-jcl")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/log4j-api-");
+		});
+	}
+
+	@TestTemplate
+	void whenAnEntryIsOptionalAndOptionalsIncludedAppearsInTheRepackagedJar(MavenBuild mavenBuild) {
+		mavenBuild.project("jar-optional-include").goals("install").execute((project) -> {
+			File repackaged = new File(project, "target/jar-optional-include-0.0.1.BUILD-SNAPSHOT.jar");
+			assertThat(jar(repackaged)).hasEntryWithNameStartingWith("BOOT-INF/classes/")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-context")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-core")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-jcl")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/log4j-api-");
+		});
+	}
+
+	@TestTemplate
+	void whenAnEntryIsOptionalAndOptionalsExcludedDoesNotAppearInTheRepackagedJar(MavenBuild mavenBuild) {
+		mavenBuild.project("jar-optional-exclude").goals("install").execute((project) -> {
+			File repackaged = new File(project, "target/jar-optional-exclude-0.0.1.BUILD-SNAPSHOT.jar");
+			assertThat(jar(repackaged)).hasEntryWithNameStartingWith("BOOT-INF/classes/")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-context")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-core")
+				.hasEntryWithNameStartingWith("BOOT-INF/lib/spring-jcl")
+				.doesNotHaveEntryWithNameStartingWith("BOOT-INF/lib/log4j-api-");
+		});
+	}
+
 	@TestTemplate
 	void whenAnEntryIsExcludedWithPropertyItDoesNotAppearInTheRepackagedJar(MavenBuild mavenBuild) {
 		mavenBuild.project("jar")

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/jar-optional-default/pom.xml

@@ -0,0 +1,47 @@
+<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>jar-optional-default</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>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-jar-plugin</artifactId>
+				<version>@maven-jar-plugin.version@</version>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring-framework.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-api</artifactId>
+			<version>@log4j2.version@</version>
+			<optional>true</optional>
+		</dependency>
+	</dependencies>
+</project>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/jar-optional-default/src/main/java/org/test/SampleApplication.java

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

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/jar-optional-exclude/pom.xml

@@ -0,0 +1,50 @@
+<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>jar-optional-exclude</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>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+						<configuration>
+							<includeOptional>false</includeOptional>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-jar-plugin</artifactId>
+				<version>@maven-jar-plugin.version@</version>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring-framework.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-api</artifactId>
+			<version>@log4j2.version@</version>
+			<optional>true</optional>
+		</dependency>
+	</dependencies>
+</project>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/jar-optional-exclude/src/main/java/org/test/SampleApplication.java

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

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/jar-optional-include/pom.xml

@@ -0,0 +1,50 @@
+<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>jar-optional-include</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>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+						<configuration>
+							<includeOptional>true</includeOptional>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-jar-plugin</artifactId>
+				<version>@maven-jar-plugin.version@</version>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring-framework.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-api</artifactId>
+			<version>@log4j2.version@</version>
+			<optional>true</optional>
+		</dependency>
+	</dependencies>
+</project>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/jar-optional-include/src/main/java/org/test/SampleApplication.java

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

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

@@ -111,6 +111,13 @@ public abstract class AbstractPackagerMojo extends AbstractDependencyFilterMojo
 	@Parameter(defaultValue = "false")
 	public boolean includeSystemScope;
 
+	/**
+	 * Include optional dependencies.
+	 * @since 3.5.7
+	 */
+	@Parameter(defaultValue = "true")
+	public boolean includeOptional = true;
+
 	/**
 	 * Include JAR tools.
 	 * @since 3.3.0
@@ -228,6 +235,9 @@ public abstract class AbstractPackagerMojo extends AbstractDependencyFilterMojo
 		if (!this.includeSystemScope) {
 			filters.add(new ScopeFilter(null, Artifact.SCOPE_SYSTEM));
 		}
+		if (!this.includeOptional) {
+			filters.add(DependencyFilter.exclude(Artifact::isOptional));
+		}
 		return filters.toArray(new ArtifactsFilter[0]);
 	}
 

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

@@ -16,9 +16,11 @@
 
 package org.springframework.boot.maven;
 
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Predicate;
 
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.shared.artifact.filter.collection.AbstractArtifactsFilter;
@@ -81,4 +83,22 @@ public abstract class DependencyFilter extends AbstractArtifactsFilter {
 		return this.filters;
 	}
 
+	/**
+	 * Return a new {@link DependencyFilter} the excludes artifacts based on the given
+	 * predicate.
+	 * @param filter the predicate used to filter the artifacts.
+	 * @return a new {@link DependencyFilter} instance
+	 * @since 3.5.7
+	 */
+	public static DependencyFilter exclude(Predicate<Artifact> filter) {
+		return new DependencyFilter(Collections.emptyList()) {
+
+			@Override
+			protected boolean filter(Artifact artifact) {
+				return filter.test(artifact);
+			}
+
+		};
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/test/java/org/springframework/boot/maven/DependencyFilterTests.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2012-present 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
+ *
+ *      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.
+ */
+
+package org.springframework.boot.maven;
+
+import java.util.Set;
+
+import org.apache.maven.artifact.Artifact;
+import org.apache.maven.artifact.DefaultArtifact;
+import org.apache.maven.artifact.handler.ArtifactHandler;
+import org.apache.maven.artifact.handler.DefaultArtifactHandler;
+import org.apache.maven.artifact.versioning.VersionRange;
+import org.apache.maven.shared.artifact.filter.collection.ArtifactFilterException;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link DependencyFilter}.
+ *
+ * @author Phillip Webb
+ */
+class DependencyFilterTests {
+
+	@Test
+	void excludeFiltersBasedOnPredicate() throws ArtifactFilterException {
+		DependencyFilter filter = DependencyFilter.exclude(Artifact::isOptional);
+		ArtifactHandler ah = new DefaultArtifactHandler();
+		VersionRange v = VersionRange.createFromVersion("1.0.0");
+		DefaultArtifact a1 = new DefaultArtifact("com.example", "a1", v, "compile", "jar", null, ah, false);
+		DefaultArtifact a2 = new DefaultArtifact("com.example", "a2", v, "compile", "jar", null, ah, true);
+		DefaultArtifact a3 = new DefaultArtifact("com.example", "a3", v, "compile", "jar", null, ah, false);
+		Set<Artifact> filtered = filter.filter(Set.of(a1, a2, a3));
+		assertThat(filtered).containsExactlyInAnyOrder(a1, a3);
+	}
+
+}