Automatically add jarmode jars when packaging

Update the `Packager` to automatically add the layertools jarmode jar
when producing a layered jar.

Closes gh-19865

Author: philwebb

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/build.gradle

@@ -11,6 +11,7 @@ def generatedResources = "${buildDir}/generated-resources/main"
 
 configurations {
 	loader
+	jarmode
 }
 
 dependencies {
@@ -22,6 +23,8 @@ dependencies {
 
 	loader(project(":spring-boot-project:spring-boot-tools:spring-boot-loader"))
 
+	jarmode(project(":spring-boot-project:spring-boot-tools:spring-boot-jarmode-layertools"))
+
 	testImplementation("org.assertj:assertj-core")
 	testImplementation("org.junit.jupiter:junit-jupiter")
 	testImplementation("org.mockito:mockito-core")
@@ -45,6 +48,18 @@ task reproducibleLoaderJar(type: Jar) {
 	destinationDirectory = file("${generatedResources}/META-INF/loader")
 }
 
+task reproducibleJarModeLayerToolsJar(type: Jar) {
+	dependsOn configurations.jarmode
+	from {
+		zipTree(configurations.jarmode.incoming.files.filter {it.name.startsWith "spring-boot-jarmode-layertools" }.singleFile)
+	}
+	reproducibleFileOrder = true
+	preserveFileTimestamps = false
+	archiveFileName = "spring-boot-jarmode-layertools.jar"
+	destinationDirectory = file("${generatedResources}/META-INF/jarmode")
+}
+
 processResources {
 	dependsOn reproducibleLoaderJar
+	dependsOn reproducibleJarModeLayerToolsJar
 }

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

@@ -20,17 +20,15 @@
 import java.io.BufferedWriter;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
-import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
+import java.util.Collection;
 import java.util.Enumeration;
 import java.util.HashSet;
-import java.util.List;
 import java.util.Set;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
@@ -127,17 +125,16 @@ public void writeEntry(String entryName, InputStream inputStream) throws IOExcep
 
 	/**
 	 * Write a nested library.
-	 * @param destination the destination of the library
+	 * @param location the destination of the library
 	 * @param library the library
 	 * @throws IOException if the write fails
 	 */
-	public void writeNestedLibrary(String destination, Library library) throws IOException {
-		File file = library.getFile();
-		JarArchiveEntry entry = new JarArchiveEntry(destination + library.getName());
-		entry.setTime(getNestedLibraryTime(file));
-		new CrcAndSize(file).setupStoredEntry(entry);
-		try (FileInputStream input = new FileInputStream(file)) {
-			writeEntry(entry, new InputStreamEntryWriter(input), new LibraryUnpackHandler(library));
+	public void writeNestedLibrary(String location, Library library) throws IOException {
+		JarArchiveEntry entry = new JarArchiveEntry(location + library.getName());
+		entry.setTime(getNestedLibraryTime(library));
+		new CrcAndSize(library::openStream).setupStoredEntry(entry);
+		try (InputStream inputStream = library.openStream()) {
+			writeEntry(entry, new InputStreamEntryWriter(inputStream), new LibraryUnpackHandler(library));
 		}
 	}
 
@@ -148,7 +145,7 @@ public void writeNestedLibrary(String destination, Library library) throws IOExc
 	 * @throws IOException if the write fails
 	 * @since 2.3.0
 	 */
-	public void writeIndexFile(String location, List<String> lines) throws IOException {
+	public void writeIndexFile(String location, Collection<String> lines) throws IOException {
 		if (location != null) {
 			JarArchiveEntry entry = new JarArchiveEntry(location);
 			writeEntry(entry, (outputStream) -> {
@@ -163,22 +160,22 @@ public void writeIndexFile(String location, List<String> lines) throws IOExcepti
 		}
 	}
 
-	private long getNestedLibraryTime(File file) {
+	private long getNestedLibraryTime(Library library) {
 		try {
-			try (JarFile jarFile = new JarFile(file)) {
-				Enumeration<JarEntry> entries = jarFile.entries();
-				while (entries.hasMoreElements()) {
-					JarEntry entry = entries.nextElement();
+			try (JarInputStream jarStream = new JarInputStream(library.openStream())) {
+				JarEntry entry = jarStream.getNextJarEntry();
+				while (entry != null) {
 					if (!entry.isDirectory()) {
 						return entry.getTime();
 					}
+					entry = jarStream.getNextJarEntry();
 				}
 			}
 		}
 		catch (Exception ex) {
-			// Ignore and just use the source file timestamp
+			// Ignore and just use the library timestamp
 		}
-		return file.lastModified();
+		return library.getLastModified();
 	}
 
 	/**
@@ -292,8 +289,8 @@ private static class CrcAndSize {
 
 		private long size;
 
-		CrcAndSize(File file) throws IOException {
-			try (FileInputStream inputStream = new FileInputStream(file)) {
+		CrcAndSize(InputStreamSupplier supplier) throws IOException {
+			try (InputStream inputStream = supplier.openStream()) {
 				load(inputStream);
 			}
 		}
@@ -380,7 +377,7 @@ public boolean requiresUnpack(String name) {
 
 		@Override
 		public String sha1Hash(String name) throws IOException {
-			return FileUtils.sha1Hash(this.library.getFile());
+			return Digest.sha1(this.library::openStream);
 		}
 
 	}

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

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2012-2020 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.io.IOException;
+import java.security.DigestInputStream;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+/**
+ * Utility class used to calculate digests.
+ *
+ * @author Phillip Webb
+ */
+final class Digest {
+
+	private Digest() {
+	}
+
+	/**
+	 * Return the SHA1 digest from the supplied stream.
+	 * @param supplier the stream supplier
+	 * @return the SHA1 digest
+	 * @throws IOException on IO error
+	 */
+	static String sha1(InputStreamSupplier supplier) throws IOException {
+		try {
+			try (DigestInputStream inputStream = new DigestInputStream(supplier.openStream(),
+					MessageDigest.getInstance("SHA-1"))) {
+				byte[] buffer = new byte[4098];
+				while (inputStream.read(buffer) != -1) {
+					// Read the entire stream
+				}
+				return bytesToHex(inputStream.getMessageDigest().digest());
+			}
+		}
+		catch (NoSuchAlgorithmException ex) {
+			throw new IllegalStateException(ex);
+		}
+	}
+
+	private static String bytesToHex(byte[] bytes) {
+		StringBuilder hex = new StringBuilder();
+		for (byte b : bytes) {
+			hex.append(String.format("%02x", b));
+		}
+		return hex.toString();
+	}
+
+}

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

@@ -17,11 +17,7 @@
 package org.springframework.boot.loader.tools;
 
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
-import java.security.DigestInputStream;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
 
 /**
  * Utilities for manipulating files and directories in Spring Boot tooling.
@@ -62,27 +58,7 @@ public static void removeDuplicatesFromOutputDirectory(File outputDirectory, Fil
 	 * @throws IOException if the file cannot be read
 	 */
 	public static String sha1Hash(File file) throws IOException {
-		try {
-			try (DigestInputStream inputStream = new DigestInputStream(new FileInputStream(file),
-					MessageDigest.getInstance("SHA-1"))) {
-				byte[] buffer = new byte[4098];
-				while (inputStream.read(buffer) != -1) {
-					// Read the entire stream
-				}
-				return bytesToHex(inputStream.getMessageDigest().digest());
-			}
-		}
-		catch (NoSuchAlgorithmException ex) {
-			throw new IllegalStateException(ex);
-		}
-	}
-
-	private static String bytesToHex(byte[] bytes) {
-		StringBuilder hex = new StringBuilder();
-		for (byte b : bytes) {
-			hex.append(String.format("%02x", b));
-		}
-		return hex.toString();
+		return Digest.sha1(InputStreamSupplier.forFile(file));
 	}
 
 }

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

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2012-2020 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.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Supplier to provide an {@link InputStream}.
+ *
+ * @author Phillip Webb
+ */
+@FunctionalInterface
+interface InputStreamSupplier {
+
+	/**
+	 * Returns a new open {@link InputStream} at the begining of the content.
+	 * @return a new {@link InputStream}
+	 * @throws IOException on IO error
+	 */
+	InputStream openStream() throws IOException;
+
+	/**
+	 * Factory method to create an {@link InputStreamSupplier} for the given {@link File}.
+	 * @param file the source file
+	 * @return a new {@link InputStreamSupplier} instance
+	 */
+	static InputStreamSupplier forFile(File file) {
+		return () -> new FileInputStream(file);
+	}
+
+}

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

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2012-2020 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.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+
+import org.springframework.util.Assert;
+
+/**
+ * {@link Library} implementation for internal jarmode jars.
+ *
+ * @author Phillip Webb
+ */
+class JarModeLibrary extends Library {
+
+	static final JarModeLibrary LAYER_TOOLS = new JarModeLibrary("spring-boot-jarmode-layertools.jar");
+
+	JarModeLibrary(String name) {
+		super(name, null, LibraryScope.RUNTIME, false);
+	}
+
+	@Override
+	InputStream openStream() throws IOException {
+		String path = "META-INF/jarmode/" + getName();
+		URL resource = getClass().getClassLoader().getResource(path);
+		Assert.state(resource != null, "Unable to find resource " + path);
+		return resource.openStream();
+	}
+
+	@Override
+	long getLastModified() {
+		return 0L;
+	}
+
+	@Override
+	public File getFile() {
+		throw new UnsupportedOperationException("Unable to access jar mode library file");
+	}
+
+}

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

@@ -17,6 +17,9 @@
 package org.springframework.boot.loader.tools;
 
 import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
 
 /**
  * Encapsulates information about a single library that may be packed into the archive.
@@ -85,6 +88,15 @@ public File getFile() {
 		return this.file;
 	}
 
+	/**
+	 * Open a stream that provides the content of the source file.
+	 * @return the file content
+	 * @throws IOException on error
+	 */
+	InputStream openStream() throws IOException {
+		return new FileInputStream(this.file);
+	}
+
 	/**
 	 * Return the scope of the library.
 	 * @return the scope
@@ -102,4 +114,8 @@ public boolean isUnpackRequired() {
 		return this.unpackRequired;
 	}
 
+	long getLastModified() {
+		return this.file.lastModified();
+	}
+
 }