Update fat jar loader to support multi-release jar files

Closes gh-12523

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

@@ -42,9 +42,9 @@ class JarEntry extends java.util.jar.JarEntry implements FileHeader {
 
 	private long localHeaderOffset;
 
-	JarEntry(JarFile jarFile, CentralDirectoryFileHeader header) {
-		super(header.getName().toString());
-		this.name = header.getName();
+	JarEntry(JarFile jarFile, CentralDirectoryFileHeader header, AsciiBytes nameAlias) {
+		super((nameAlias != null) ? nameAlias.toString() : header.getName().toString());
+		this.name = (nameAlias != null) ? nameAlias : header.getName();
 		this.jarFile = jarFile;
 		this.localHeaderOffset = header.getLocalHeaderOffset();
 		setCompressedSize(header.getCompressedSize());

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

@@ -24,6 +24,9 @@ import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.NoSuchElementException;
+import java.util.jar.Attributes;
+import java.util.jar.Attributes.Name;
+import java.util.jar.Manifest;
 import java.util.zip.ZipEntry;
 
 import org.springframework.boot.loader.data.RandomAccessData;
@@ -44,6 +47,27 @@ import org.springframework.boot.loader.data.RandomAccessData;
  */
 class JarFileEntries implements CentralDirectoryVisitor, Iterable<JarEntry> {
 
+	private static final String META_INF_PREFIX = "META-INF/";
+
+	private static final Name MULTI_RELEASE = new Name("Multi-Release");
+
+	private static final int BASE_VERSION = 8;
+
+	private static final int RUNTIME_VERSION;
+
+	static {
+		int version;
+		try {
+			Object runtimeVersion = Runtime.class.getMethod("version").invoke(null);
+			version = (int) runtimeVersion.getClass().getMethod("major")
+					.invoke(runtimeVersion);
+		}
+		catch (Throwable ex) {
+			version = 8;
+		}
+		RUNTIME_VERSION = version;
+	}
+
 	private static final long LOCAL_FILE_HEADER_SIZE = 30;
 
 	private static final char SLASH = '/';
@@ -66,6 +90,8 @@ class JarFileEntries implements CentralDirectoryVisitor, Iterable<JarEntry> {
 
 	private int[] positions;
 
+	private Boolean multiReleaseJar;
+
 	private final Map<Integer, FileHeader> entriesCache = Collections
 			.synchronizedMap(new LinkedHashMap<Integer, FileHeader>(16, 0.75f, true) {
 
@@ -83,6 +109,9 @@ class JarFileEntries implements CentralDirectoryVisitor, Iterable<JarEntry> {
 	JarFileEntries(JarFile jarFile, JarEntryFilter filter) {
 		this.jarFile = jarFile;
 		this.filter = filter;
+		if (RUNTIME_VERSION == BASE_VERSION) {
+			this.multiReleaseJar = false;
+		}
 	}
 
 	@Override
@@ -216,21 +245,68 @@ class JarFileEntries implements CentralDirectoryVisitor, Iterable<JarEntry> {
 
 	private <T extends FileHeader> T getEntry(CharSequence name, Class<T> type,
 			boolean cacheEntry) {
+		T entry = doGetEntry(name, type, cacheEntry, null);
+		if (isMultiReleaseJar() && !isMetaInfEntry(name)) {
+			int version = RUNTIME_VERSION;
+			AsciiBytes nameAlias = (entry instanceof JarEntry)
+					? ((JarEntry) entry).getAsciiBytesName()
+					: new AsciiBytes(name.toString());
+			while (version > BASE_VERSION) {
+				T versionedEntry = doGetEntry("META-INF/versions/" + version + "/" + name,
+						type, cacheEntry, nameAlias);
+				if (versionedEntry != null) {
+					return versionedEntry;
+				}
+				version--;
+			}
+		}
+		return entry;
+	}
+
+	private boolean isMetaInfEntry(CharSequence name) {
+		return name.toString().startsWith(META_INF_PREFIX);
+	}
+
+	private boolean isMultiReleaseJar() {
+		Boolean multiRelease = this.multiReleaseJar;
+		if (multiRelease != null) {
+			return multiRelease;
+		}
+		try {
+			Manifest manifest = this.jarFile.getManifest();
+			if (manifest == null) {
+				multiRelease = false;
+			}
+			else {
+				Attributes attributes = manifest.getMainAttributes();
+				multiRelease = attributes.containsKey(MULTI_RELEASE);
+			}
+		}
+		catch (IOException ex) {
+			multiRelease = false;
+		}
+		this.multiReleaseJar = multiRelease;
+		return multiRelease;
+	}
+
+	private <T extends FileHeader> T doGetEntry(CharSequence name, Class<T> type,
+			boolean cacheEntry, AsciiBytes nameAlias) {
 		int hashCode = AsciiBytes.hashCode(name);
-		T entry = getEntry(hashCode, name, NO_SUFFIX, type, cacheEntry);
+		T entry = getEntry(hashCode, name, NO_SUFFIX, type, cacheEntry, nameAlias);
 		if (entry == null) {
 			hashCode = AsciiBytes.hashCode(hashCode, SLASH);
-			entry = getEntry(hashCode, name, SLASH, type, cacheEntry);
+			entry = getEntry(hashCode, name, SLASH, type, cacheEntry, nameAlias);
 		}
 		return entry;
 	}
 
 	private <T extends FileHeader> T getEntry(int hashCode, CharSequence name,
-			char suffix, Class<T> type, boolean cacheEntry) {
+			char suffix, Class<T> type, boolean cacheEntry, AsciiBytes nameAlias) {
 		int index = getFirstIndex(hashCode);
 		while (index >= 0 && index < this.size && this.hashCodes[index] == hashCode) {
-			T entry = getEntry(index, type, cacheEntry);
-			if (entry.hasName(name, suffix)) {
+			T entry = getEntry(index, type, cacheEntry, nameAlias);
+			if (entry.hasName((nameAlias != null) ? nameAlias.toString() : name,
+					suffix)) {
 				return entry;
 			}
 			index++;
@@ -240,7 +316,7 @@ class JarFileEntries implements CentralDirectoryVisitor, Iterable<JarEntry> {
 
 	@SuppressWarnings("unchecked")
 	private <T extends FileHeader> T getEntry(int index, Class<T> type,
-			boolean cacheEntry) {
+			boolean cacheEntry, AsciiBytes nameAlias) {
 		try {
 			FileHeader cached = this.entriesCache.get(index);
 			FileHeader entry = (cached != null) ? cached
@@ -249,7 +325,8 @@ class JarFileEntries implements CentralDirectoryVisitor, Iterable<JarEntry> {
 							this.centralDirectoryOffsets[index], this.filter);
 			if (CentralDirectoryFileHeader.class.equals(entry.getClass())
 					&& type.equals(JarEntry.class)) {
-				entry = new JarEntry(this.jarFile, (CentralDirectoryFileHeader) entry);
+				entry = new JarEntry(this.jarFile, (CentralDirectoryFileHeader) entry,
+						nameAlias);
 			}
 			if (cacheEntry && cached != entry) {
 				this.entriesCache.put(index, entry);
@@ -299,7 +376,7 @@ class JarFileEntries implements CentralDirectoryVisitor, Iterable<JarEntry> {
 			}
 			int entryIndex = JarFileEntries.this.positions[this.index];
 			this.index++;
-			return getEntry(entryIndex, JarEntry.class, false);
+			return getEntry(entryIndex, JarEntry.class, false, null);
 		}
 
 	}

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

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -52,13 +52,25 @@ public abstract class TestJarCreator {
 			writeNestedEntry("nested.jar", unpackNested, jarOutputStream);
 			writeNestedEntry("another-nested.jar", unpackNested, jarOutputStream);
 			writeNestedEntry("space nested.jar", unpackNested, jarOutputStream);
+			writeNestedMultiReleaseEntry("multi-release.jar", unpackNested,
+					jarOutputStream);
 		}
 	}
 
 	private static void writeNestedEntry(String name, boolean unpackNested,
 			JarOutputStream jarOutputStream) throws Exception {
+		writeNestedEntry(name, unpackNested, jarOutputStream, false);
+	}
+
+	private static void writeNestedMultiReleaseEntry(String name, boolean unpackNested,
+			JarOutputStream jarOutputStream) throws Exception {
+		writeNestedEntry(name, unpackNested, jarOutputStream, true);
+	}
+
+	private static void writeNestedEntry(String name, boolean unpackNested,
+			JarOutputStream jarOutputStream, boolean multiRelease) throws Exception {
 		JarEntry nestedEntry = new JarEntry(name);
-		byte[] nestedJarData = getNestedJarData();
+		byte[] nestedJarData = getNestedJarData(multiRelease);
 		nestedEntry.setSize(nestedJarData.length);
 		nestedEntry.setCompressedSize(nestedJarData.length);
 		if (unpackNested) {
@@ -74,23 +86,40 @@ public abstract class TestJarCreator {
 		jarOutputStream.closeEntry();
 	}
 
-	private static byte[] getNestedJarData() throws Exception {
+	private static byte[] getNestedJarData(boolean multiRelease) throws Exception {
 		ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
 		JarOutputStream jarOutputStream = new JarOutputStream(byteArrayOutputStream);
-		writeManifest(jarOutputStream, "j2");
-		writeEntry(jarOutputStream, "3.dat", 3);
-		writeEntry(jarOutputStream, "4.dat", 4);
-		writeEntry(jarOutputStream, "\u00E4.dat", '\u00E4');
+		writeManifest(jarOutputStream, "j2", multiRelease);
+		if (multiRelease) {
+			writeEntry(jarOutputStream, "multi-release.dat", 8);
+			writeEntry(jarOutputStream, "META-INF/versions/9/multi-release.dat", 9);
+			writeEntry(jarOutputStream, "META-INF/versions/10/multi-release.dat", 10);
+			writeEntry(jarOutputStream, "META-INF/versions/11/multi-release.dat", 11);
+		}
+		else {
+			writeEntry(jarOutputStream, "3.dat", 3);
+			writeEntry(jarOutputStream, "4.dat", 4);
+			writeEntry(jarOutputStream, "\u00E4.dat", '\u00E4');
+		}
 		jarOutputStream.close();
 		return byteArrayOutputStream.toByteArray();
 	}
 
 	private static void writeManifest(JarOutputStream jarOutputStream, String name)
 			throws Exception {
+		writeManifest(jarOutputStream, name, false);
+	}
+
+	private static void writeManifest(JarOutputStream jarOutputStream, String name,
+			boolean multiRelease) throws Exception {
 		writeDirEntry(jarOutputStream, "META-INF/");
 		Manifest manifest = new Manifest();
 		manifest.getMainAttributes().putValue("Built-By", name);
 		manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0");
+		if (multiRelease) {
+			manifest.getMainAttributes().putValue("Multi-Release",
+					Boolean.toString(true));
+		}
 		jarOutputStream.putNextEntry(new ZipEntry("META-INF/MANIFEST.MF"));
 		manifest.write(jarOutputStream);
 		jarOutputStream.closeEntry();

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

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -108,7 +108,7 @@ public class ExplodedArchiveTests {
 	@Test
 	public void getEntries() {
 		Map<String, Archive.Entry> entries = getEntriesMap(this.archive);
-		assertThat(entries.size()).isEqualTo(11);
+		assertThat(entries.size()).isEqualTo(12);
 	}
 
 	@Test

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

@@ -78,7 +78,7 @@ public class JarFileArchiveTests {
 	@Test
 	public void getEntries() {
 		Map<String, Archive.Entry> entries = getEntriesMap(this.archive);
-		assertThat(entries.size()).isEqualTo(11);
+		assertThat(entries.size()).isEqualTo(12);
 	}
 
 	@Test

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

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -82,6 +82,7 @@ public class CentralDirectoryParserTests {
 		assertThat(headers.next().getName().toString()).isEqualTo("nested.jar");
 		assertThat(headers.next().getName().toString()).isEqualTo("another-nested.jar");
 		assertThat(headers.next().getName().toString()).isEqualTo("space nested.jar");
+		assertThat(headers.next().getName().toString()).isEqualTo("multi-release.jar");
 		assertThat(headers.hasNext()).isFalse();
 	}
 

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

@@ -91,6 +91,7 @@ public class JarFileTests {
 		assertThat(entries.nextElement().getName()).isEqualTo("nested.jar");
 		assertThat(entries.nextElement().getName()).isEqualTo("another-nested.jar");
 		assertThat(entries.nextElement().getName()).isEqualTo("space nested.jar");
+		assertThat(entries.nextElement().getName()).isEqualTo("multi-release.jar");
 		assertThat(entries.hasMoreElements()).isFalse();
 		URL jarUrl = new URL("jar:" + this.rootJarFile.toURI() + "!/");
 		URLClassLoader urlClassLoader = new URLClassLoader(new URL[] { jarUrl });
@@ -134,6 +135,7 @@ public class JarFileTests {
 		assertThat(entries.nextElement().getName()).isEqualTo("nested.jar");
 		assertThat(entries.nextElement().getName()).isEqualTo("another-nested.jar");
 		assertThat(entries.nextElement().getName()).isEqualTo("space nested.jar");
+		assertThat(entries.nextElement().getName()).isEqualTo("multi-release.jar");
 		assertThat(entries.hasMoreElements()).isFalse();
 	}
 
@@ -499,4 +501,26 @@ public class JarFileTests {
 		}
 	}
 
+	@Test
+	public void multiReleaseEntry() throws Exception {
+		JarFile multiRelease = this.jarFile
+				.getNestedJarFile(this.jarFile.getEntry("multi-release.jar"));
+		ZipEntry entry = multiRelease.getEntry("multi-release.dat");
+		assertThat(entry.getName()).isEqualTo("multi-release.dat");
+		InputStream inputStream = multiRelease.getInputStream(entry);
+		assertThat(inputStream.available()).isEqualTo(1);
+		assertThat(inputStream.read()).isEqualTo(getJavaVersion());
+	}
+
+	private int getJavaVersion() {
+		try {
+			Object runtimeVersion = Runtime.class.getMethod("version").invoke(null);
+			return (int) runtimeVersion.getClass().getMethod("major")
+					.invoke(runtimeVersion);
+		}
+		catch (Throwable ex) {
+			return 8;
+		}
+	}
+
 }