Polish "Support zip64 jars"

See gh-16091

spring-boot-project/spring-boot-docs/src/main/asciidoc/deployment.adoc

@@ -404,6 +404,10 @@ Currently, some tools do not accept this format, so you may not always be able t
 For example, `jar -xf` may silently fail to extract a jar or war that has been made fully executable.
 It is recommended that you make your jar or war fully executable only if you intend to execute it directly, rather than running it with `java -jar`or deploying it to a servlet container.
 
+CAUTION: A zip64-format jar file cannot be made fully executable.
+Attempting to do so will result in a jar file that is reported as corrupt when executed directly or with `java -jar`.
+A standard-format jar file that contains one or more zip64-format nested jars can be fully executable.
+
 To create a '`fully executable`' jar with Maven, use the following plugin configuration:
 
 [source,xml,indent=0,subs="verbatim,quotes,attributes"]

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

@@ -17,7 +17,6 @@
 package org.springframework.boot.loader.jar;
 
 import java.io.IOException;
-import java.util.Optional;
 
 import org.springframework.boot.loader.data.RandomAccessData;
 
@@ -45,7 +44,7 @@ class CentralDirectoryEndRecord {
 
 	private static final int READ_BLOCK_SIZE = 256;
 
-	private final Optional<Zip64End> zip64End;
+	private final Zip64End zip64End;
 
 	private byte[] block;
 
@@ -76,8 +75,7 @@ class CentralDirectoryEndRecord {
 			this.offset = this.block.length - this.size;
 		}
 		int startOfCentralDirectoryEndRecord = (int) (data.getSize() - this.size);
-		this.zip64End = Optional.ofNullable(
-				isZip64() ? new Zip64End(data, startOfCentralDirectoryEndRecord) : null);
+		this.zip64End = isZip64() ? new Zip64End(data, startOfCentralDirectoryEndRecord) : null;
 	}
 
 	private byte[] createBlockFromEndOfData(RandomAccessData data, int size) throws IOException {
@@ -94,6 +92,10 @@ class CentralDirectoryEndRecord {
 		return this.size == MINIMUM_SIZE + commentLength;
 	}
 
+	private boolean isZip64() {
+		return (int) Bytes.littleEndianValue(this.block, this.offset + 10, 2) == ZIP64_MAGICCOUNT;
+	}
+
 	/**
 	 * Returns the location in the data that the archive actually starts. For most files
 	 * the archive data will start at 0, however, it is possible to have prefixed bytes
@@ -104,10 +106,9 @@ class CentralDirectoryEndRecord {
 	long getStartOfArchive(RandomAccessData data) {
 		long length = Bytes.littleEndianValue(this.block, this.offset + 12, 4);
 		long specifiedOffset = Bytes.littleEndianValue(this.block, this.offset + 16, 4);
-		long zip64EndSize = this.zip64End.map((x) -> x.getSize()).orElse(0L);
-		int zip64LocSize = this.zip64End.map((x) -> Zip64Locator.ZIP64_LOCSIZE).orElse(0);
-		long actualOffset = data.getSize() - this.size - length - zip64EndSize
-				- zip64LocSize;
+		long zip64EndSize = (this.zip64End != null) ? this.zip64End.getSize() : 0L;
+		int zip64LocSize = (this.zip64End != null) ? Zip64Locator.ZIP64_LOCSIZE : 0;
+		long actualOffset = data.getSize() - this.size - length - zip64EndSize - zip64LocSize;
 		return actualOffset - specifiedOffset;
 	}
 
@@ -118,14 +119,12 @@ class CentralDirectoryEndRecord {
 	 * @return the central directory data
 	 */
 	RandomAccessData getCentralDirectory(RandomAccessData data) {
-		if (isZip64()) {
-			return this.zip64End.get().getCentratDirectory(data);
-		}
-		else {
-			long offset = Bytes.littleEndianValue(this.block, this.offset + 16, 4);
-			long length = Bytes.littleEndianValue(this.block, this.offset + 12, 4);
-			return data.getSubsection(offset, length);
+		if (this.zip64End != null) {
+			return this.zip64End.getCentralDirectory(data);
 		}
+		long offset = Bytes.littleEndianValue(this.block, this.offset + 16, 4);
+		long length = Bytes.littleEndianValue(this.block, this.offset + 12, 4);
+		return data.getSubsection(offset, length);
 	}
 
 	/**
@@ -133,19 +132,17 @@ class CentralDirectoryEndRecord {
 	 * @return the number of records in the zip
 	 */
 	int getNumberOfRecords() {
-		if (isZip64()) {
-			return this.zip64End.get().getNumberOfRecords();
-		}
-		else {
-			long numberOfRecords = Bytes.littleEndianValue(this.block, this.offset + 10,
-					2);
-			return (int) numberOfRecords;
+		if (this.zip64End != null) {
+			return this.zip64End.getNumberOfRecords();
 		}
+		long numberOfRecords = Bytes.littleEndianValue(this.block, this.offset + 10, 2);
+		return (int) numberOfRecords;
 	}
 
-	boolean isZip64() {
-		return (int) Bytes.littleEndianValue(this.block, this.offset + 10,
-				2) == ZIP64_MAGICCOUNT;
+	String getComment() {
+		int commentLength = (int) Bytes.littleEndianValue(this.block, this.offset + COMMENT_LENGTH_OFFSET, 2);
+		AsciiBytes comment = new AsciiBytes(this.block, this.offset + COMMENT_LENGTH_OFFSET + 2, commentLength);
+		return comment.toString();
 	}
 
 	/**
@@ -154,11 +151,13 @@ class CentralDirectoryEndRecord {
 	 * @see <a href="https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT">Chapter
 	 * 4.3.14 of Zip64 specification</a>
 	 */
-	private static class Zip64End {
+	private static final class Zip64End {
 
-		static final int ZIP64_ENDTOT = 32; // total number of entries
-		static final int ZIP64_ENDSIZ = 40; // central directory size in bytes
-		static final int ZIP64_ENDOFF = 48; // offset of first CEN header
+		private static final int ZIP64_ENDTOT = 32; // total number of entries
+
+		private static final int ZIP64_ENDSIZ = 40; // central directory size in bytes
+
+		private static final int ZIP64_ENDOFF = 48; // offset of first CEN header
 
 		private final Zip64Locator locator;
 
@@ -168,12 +167,11 @@ class CentralDirectoryEndRecord {
 
 		private int numberOfRecords;
 
-		Zip64End(RandomAccessData data, int centratDirectoryEndOffset)
-				throws IOException {
+		private Zip64End(RandomAccessData data, int centratDirectoryEndOffset) throws IOException {
 			this(data, new Zip64Locator(data, centratDirectoryEndOffset));
 		}
 
-		Zip64End(RandomAccessData data, Zip64Locator locator) throws IOException {
+		private Zip64End(RandomAccessData data, Zip64Locator locator) throws IOException {
 			this.locator = locator;
 			byte[] block = data.read(locator.getZip64EndOffset(), 56);
 			this.centralDirectoryOffset = Bytes.littleEndianValue(block, ZIP64_ENDOFF, 8);
@@ -185,7 +183,7 @@ class CentralDirectoryEndRecord {
 		 * Return the size of this zip 64 end of central directory record.
 		 * @return size of this zip 64 end of central directory record
 		 */
-		public long getSize() {
+		private long getSize() {
 			return this.locator.getZip64EndSize();
 		}
 
@@ -195,16 +193,15 @@ class CentralDirectoryEndRecord {
 		 * @param data the source data
 		 * @return the central directory data
 		 */
-		public RandomAccessData getCentratDirectory(RandomAccessData data) {
-			return data.getSubsection(this.centralDirectoryOffset,
-					this.centralDirectoryLength);
+		private RandomAccessData getCentralDirectory(RandomAccessData data) {
+			return data.getSubsection(this.centralDirectoryOffset, this.centralDirectoryLength);
 		}
 
 		/**
 		 * Return the number of entries in the zip64 archive.
 		 * @return the number of records in the zip
 		 */
-		public int getNumberOfRecords() {
+		private int getNumberOfRecords() {
 			return this.numberOfRecords;
 		}
 
@@ -216,7 +213,7 @@ class CentralDirectoryEndRecord {
 	 * @see <a href="https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT">Chapter
 	 * 4.3.15 of Zip64 specification</a>
 	 */
-	private static class Zip64Locator {
+	private static final class Zip64Locator {
 
 		static final int ZIP64_LOCSIZE = 20; // locator size
 		static final int ZIP64_LOCOFF = 8; // offset of zip64 end
@@ -225,8 +222,7 @@ class CentralDirectoryEndRecord {
 
 		private final int offset;
 
-		Zip64Locator(RandomAccessData data, int centralDirectoryEndOffset)
-				throws IOException {
+		private Zip64Locator(RandomAccessData data, int centralDirectoryEndOffset) throws IOException {
 			this.offset = centralDirectoryEndOffset - ZIP64_LOCSIZE;
 			byte[] block = data.read(this.offset, ZIP64_LOCSIZE);
 			this.zip64EndOffset = Bytes.littleEndianValue(block, ZIP64_LOCOFF, 8);
@@ -236,7 +232,7 @@ class CentralDirectoryEndRecord {
 		 * Return the size of the zip 64 end record located by this zip64 end locator.
 		 * @return size of the zip 64 end record located by this zip64 end locator
 		 */
-		public long getZip64EndSize() {
+		private long getZip64EndSize() {
 			return this.offset - this.zip64EndOffset;
 		}
 
@@ -244,16 +240,10 @@ class CentralDirectoryEndRecord {
 		 * Return the offset to locate {@link Zip64End}.
 		 * @return offset of the Zip64 end of central directory record
 		 */
-		public long getZip64EndOffset() {
+		private long getZip64EndOffset() {
 			return this.zip64EndOffset;
 		}
 
 	}
 
-	String getComment() {
-		int commentLength = (int) Bytes.littleEndianValue(this.block, this.offset + COMMENT_LENGTH_OFFSET, 2);
-		AsciiBytes comment = new AsciiBytes(this.block, this.offset + COMMENT_LENGTH_OFFSET + 2, commentLength);
-		return comment.toString();
-	}
-
 }

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

@@ -143,14 +143,15 @@ class JarFileArchiveTests {
 	}
 
 	@Test
-	void filesInzip64ArchivesAreAllListed() throws IOException {
+	void filesInZip64ArchivesAreAllListed() throws IOException {
 		File file = new File(this.tempDir, "test.jar");
 		FileCopyUtils.copy(writeZip64Jar(), file);
-		JarFileArchive zip64Archive = new JarFileArchive(file);
-		Iterator<Entry> it = zip64Archive.iterator();
-		for (int i = 0; i < 65537; i++) {
-			assertThat(it.hasNext()).as(i + "nth file is present").isTrue();
-			it.next();
+		try (JarFileArchive zip64Archive = new JarFileArchive(file)) {
+			Iterator<Entry> entries = zip64Archive.iterator();
+			for (int i = 0; i < 65537; i++) {
+				assertThat(entries.hasNext()).as(i + "nth file is present").isTrue();
+				entries.next();
+			}
 		}
 	}
 

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

@@ -16,19 +16,26 @@
 
 package org.springframework.boot.loader.jar;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.FilePermission;
+import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
 import java.util.Enumeration;
+import java.util.List;
 import java.util.jar.JarEntry;
 import java.util.jar.JarInputStream;
+import java.util.jar.JarOutputStream;
 import java.util.jar.Manifest;
+import java.util.zip.CRC32;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
@@ -512,6 +519,65 @@ class JarFileTests {
 		}
 	}
 
+	@Test
+	void zip64JarCanBeRead() throws Exception {
+		File zip64Jar = new File(this.tempDir, "zip64.jar");
+		FileCopyUtils.copy(zip64Jar(), zip64Jar);
+		try (JarFile zip64JarFile = new JarFile(zip64Jar)) {
+			List<JarEntry> entries = Collections.list(zip64JarFile.entries());
+			assertThat(entries).hasSize(65537);
+			for (int i = 0; i < entries.size(); i++) {
+				JarEntry entry = entries.get(i);
+				InputStream entryInput = zip64JarFile.getInputStream(entry);
+				String contents = StreamUtils.copyToString(entryInput, StandardCharsets.UTF_8);
+				assertThat(contents).isEqualTo("Entry " + (i + 1));
+			}
+		}
+	}
+
+	@Test
+	void nestedZip64JarCanBeRead() throws Exception {
+		File outer = new File(this.tempDir, "outer.jar");
+		try (JarOutputStream jarOutput = new JarOutputStream(new FileOutputStream(outer))) {
+			JarEntry nestedEntry = new JarEntry("nested-zip64.jar");
+			byte[] contents = zip64Jar();
+			nestedEntry.setSize(contents.length);
+			nestedEntry.setCompressedSize(contents.length);
+			CRC32 crc32 = new CRC32();
+			crc32.update(contents);
+			nestedEntry.setCrc(crc32.getValue());
+			nestedEntry.setMethod(ZipEntry.STORED);
+			jarOutput.putNextEntry(nestedEntry);
+			jarOutput.write(contents);
+			jarOutput.closeEntry();
+		}
+		try (JarFile outerJarFile = new JarFile(outer)) {
+			try (JarFile nestedZip64JarFile = outerJarFile
+					.getNestedJarFile(outerJarFile.getJarEntry("nested-zip64.jar"))) {
+				List<JarEntry> entries = Collections.list(nestedZip64JarFile.entries());
+				assertThat(entries).hasSize(65537);
+				for (int i = 0; i < entries.size(); i++) {
+					JarEntry entry = entries.get(i);
+					InputStream entryInput = nestedZip64JarFile.getInputStream(entry);
+					String contents = StreamUtils.copyToString(entryInput, StandardCharsets.UTF_8);
+					assertThat(contents).isEqualTo("Entry " + (i + 1));
+				}
+			}
+		}
+	}
+
+	private byte[] zip64Jar() throws IOException {
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+		JarOutputStream jarOutput = new JarOutputStream(bytes);
+		for (int i = 0; i < 65537; i++) {
+			jarOutput.putNextEntry(new JarEntry(i + ".dat"));
+			jarOutput.write(("Entry " + (i + 1)).getBytes(StandardCharsets.UTF_8));
+			jarOutput.closeEntry();
+		}
+		jarOutput.close();
+		return bytes.toByteArray();
+	}
+
 	private int getJavaVersion() {
 		try {
 			Object runtimeVersion = Runtime.class.getMethod("version").invoke(null);