Only add native-image argfile when excludes are uses

Closes spring-projectsgh-33363

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootZipCopyAction.java

@@ -22,7 +22,6 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
-import java.util.ArrayList;
 import java.util.Calendar;
 import java.util.Collection;
 import java.util.GregorianCalendar;
@@ -59,6 +58,7 @@
 import org.springframework.boot.loader.tools.Layer;
 import org.springframework.boot.loader.tools.LayersIndex;
 import org.springframework.boot.loader.tools.LibraryCoordinates;
+import org.springframework.boot.loader.tools.NativeImageUtils;
 import org.springframework.util.Assert;
 import org.springframework.util.StreamUtils;
 import org.springframework.util.StringUtils;
@@ -369,15 +369,8 @@ private void writeNativeImageArgFileIfNecessary() throws IOException {
 					}
 				}
 			}
-			if (excludes != null) {
-				List<String> args = new ArrayList<>();
-				for (String exclude : excludes) {
-					int lastSlash = exclude.lastIndexOf('/');
-					String jar = (lastSlash != -1) ? exclude.substring(lastSlash + 1) : exclude;
-					args.add("--exclude-config");
-					args.add(Pattern.quote(jar));
-					args.add("^/META-INF/native-image/.*");
-				}
+			List<String> args = NativeImageUtils.createExcludeConfigArguments(excludes);
+			if (!args.isEmpty()) {
 				ZipEntryContentWriter writer = ZipEntryContentWriter.fromLines(BootZipCopyAction.this.encoding, args);
 				writeEntry("META-INF/native-image/argfile", writer, true);
 			}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/BootJarTests.java

@@ -201,6 +201,13 @@ void nativeImageArgFileWithExcludesIsWritten() throws IOException {
 		}
 	}
 
+	@Test
+	void nativeImageArgFileIsNotWrittenWhenExcludesAreEmpty() throws IOException {
+		try (JarFile jarFile = new JarFile(createLayeredJar(false))) {
+			assertThat(jarFile.getEntry("META-INF/native-image/argfile")).isNull();
+		}
+	}
+
 	@Test
 	void javaVersionIsWrittenToManifest() throws IOException {
 		try (JarFile jarFile = new JarFile(createPopulatedJar())) {

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/src/main/java/org/springframework/boot/loader/tools/NativeImageUtils.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2012-2022 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.loader.tools;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Pattern;
+
+/**
+ * Utilities for working with GraalVM native images.
+ *
+ * @author Moritz Halbritter
+ * @since 3.0.0
+ */
+public final class NativeImageUtils {
+
+	private NativeImageUtils() {
+	}
+
+	/**
+	 * Creates the arguments passed to native-image for the exclusion of reachability
+	 * metadata.
+	 * @param excludes dependencies for which the reachability metadata should be excluded
+	 * @return arguments for native-image
+	 */
+	public static List<String> createExcludeConfigArguments(Iterable<String> excludes) {
+		List<String> args = new ArrayList<>();
+		for (String exclude : excludes) {
+			int lastSlash = exclude.lastIndexOf('/');
+			String jar = (lastSlash != -1) ? exclude.substring(lastSlash + 1) : exclude;
+			args.add("--exclude-config");
+			args.add(Pattern.quote(jar));
+			args.add("^/META-INF/native-image/.*");
+		}
+		return args;
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/src/main/java/org/springframework/boot/loader/tools/Packager.java

@@ -37,8 +37,6 @@
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.jar.Manifest;
-import java.util.regex.Pattern;
-import java.util.stream.Collectors;
 import java.util.zip.ZipEntry;
 
 import org.apache.commons.compress.archivers.jar.JarArchiveEntry;
@@ -241,16 +239,9 @@ private void writeNativeImageArgFile(AbstractJarWriter writer, JarFile sourceJar
 				}
 			}
 		}
-		if (!excludes.isEmpty()) {
-			List<String> args = new ArrayList<>();
-			for (String exclude : excludes) {
-				int lastSlash = exclude.lastIndexOf('/');
-				String jar = (lastSlash != -1) ? exclude.substring(lastSlash + 1) : exclude;
-				args.add("--exclude-config");
-				args.add(Pattern.quote(jar));
-				args.add("^/META-INF/native-image/.*");
-			}
-			String contents = args.stream().collect(Collectors.joining("\n")) + "\n";
+		List<String> args = NativeImageUtils.createExcludeConfigArguments(excludes);
+		if (!args.isEmpty()) {
+			String contents = String.join("\n", args) + "\n";
 			writer.writeEntry("META-INF/native-image/argfile",
 					new ByteArrayInputStream(contents.getBytes(StandardCharsets.UTF_8)));
 		}

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/src/test/java/org/springframework/boot/loader/tools/NativeImageUtilsTests.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2012-2022 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.loader.tools;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for @{link NativeImageUtils}.
+ *
+ * @author Moritz Halbritter
+ */
+class NativeImageUtilsTests {
+
+	@Test
+	void shouldCreateExcludeConfigArguments() {
+		List<String> arguments = NativeImageUtils
+				.createExcludeConfigArguments(List.of("path/to/dependency-1.jar", "dependency-2.jar"));
+		assertThat(arguments).containsExactly("--exclude-config", "\\Qdependency-1.jar\\E",
+				"^/META-INF/native-image/.*", "--exclude-config", "\\Qdependency-2.jar\\E",
+				"^/META-INF/native-image/.*");
+	}
+
+}