Java tutorial
/* * 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. * You may obtain a copy of the License at * * http://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.BufferedInputStream; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.FilterInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.URL; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.attribute.PosixFilePermission; import java.util.Arrays; import java.util.Enumeration; import java.util.HashSet; import java.util.Set; import java.util.jar.JarEntry; import java.util.jar.JarFile; import java.util.jar.JarInputStream; import java.util.jar.Manifest; import java.util.zip.CRC32; import java.util.zip.ZipEntry; import org.apache.commons.compress.archivers.jar.JarArchiveEntry; import org.apache.commons.compress.archivers.jar.JarArchiveOutputStream; import org.apache.commons.compress.archivers.zip.UnixStat; /** * Writes JAR content, ensuring valid directory entries are always created and duplicate * items are ignored. * * @author Phillip Webb * @author Andy Wilkinson */ public class JarWriter implements LoaderClassesWriter, AutoCloseable { private static final UnpackHandler NEVER_UNPACK = new NeverUnpackHandler(); private static final String NESTED_LOADER_JAR = "META-INF/loader/spring-boot-loader.jar"; private static final int BUFFER_SIZE = 32 * 1024; private final JarArchiveOutputStream jarOutput; private final Set<String> writtenEntries = new HashSet<>(); /** * Create a new {@link JarWriter} instance. * @param file the file to write * @throws IOException if the file cannot be opened * @throws FileNotFoundException if the file cannot be found */ public JarWriter(File file) throws FileNotFoundException, IOException { this(file, null); } /** * Create a new {@link JarWriter} instance. * @param file the file to write * @param launchScript an optional launch script to prepend to the front of the jar * @throws IOException if the file cannot be opened * @throws FileNotFoundException if the file cannot be found */ public JarWriter(File file, LaunchScript launchScript) throws FileNotFoundException, IOException { FileOutputStream fileOutputStream = new FileOutputStream(file); if (launchScript != null) { fileOutputStream.write(launchScript.toByteArray()); setExecutableFilePermission(file); } this.jarOutput = new JarArchiveOutputStream(fileOutputStream); this.jarOutput.setEncoding("UTF-8"); } private void setExecutableFilePermission(File file) { try { Path path = file.toPath(); Set<PosixFilePermission> permissions = new HashSet<>(Files.getPosixFilePermissions(path)); permissions.add(PosixFilePermission.OWNER_EXECUTE); Files.setPosixFilePermissions(path, permissions); } catch (Throwable ex) { // Ignore and continue creating the jar } } /** * Write the specified manifest. * @param manifest the manifest to write * @throws IOException of the manifest cannot be written */ public void writeManifest(Manifest manifest) throws IOException { JarArchiveEntry entry = new JarArchiveEntry("META-INF/MANIFEST.MF"); writeEntry(entry, manifest::write); } /** * Write all entries from the specified jar file. * @param jarFile the source jar file * @throws IOException if the entries cannot be written */ public void writeEntries(JarFile jarFile) throws IOException { this.writeEntries(jarFile, new IdentityEntryTransformer(), NEVER_UNPACK); } void writeEntries(JarFile jarFile, UnpackHandler unpackHandler) throws IOException { this.writeEntries(jarFile, new IdentityEntryTransformer(), unpackHandler); } void writeEntries(JarFile jarFile, EntryTransformer entryTransformer, UnpackHandler unpackHandler) throws IOException { Enumeration<JarEntry> entries = jarFile.entries(); while (entries.hasMoreElements()) { JarArchiveEntry entry = new JarArchiveEntry(entries.nextElement()); setUpEntry(jarFile, entry); try (ZipHeaderPeekInputStream inputStream = new ZipHeaderPeekInputStream( jarFile.getInputStream(entry))) { EntryWriter entryWriter = new InputStreamEntryWriter(inputStream, true); JarArchiveEntry transformedEntry = entryTransformer.transform(entry); if (transformedEntry != null) { writeEntry(transformedEntry, entryWriter, unpackHandler); } } } } private void setUpEntry(JarFile jarFile, JarArchiveEntry entry) throws IOException { try (ZipHeaderPeekInputStream inputStream = new ZipHeaderPeekInputStream(jarFile.getInputStream(entry))) { if (inputStream.hasZipHeader() && entry.getMethod() != ZipEntry.STORED) { new CrcAndSize(inputStream).setupStoredEntry(entry); } else { entry.setCompressedSize(-1); } } } /** * Writes an entry. The {@code inputStream} is closed once the entry has been written * @param entryName the name of the entry * @param inputStream the stream from which the entry's data can be read * @throws IOException if the write fails */ @Override public void writeEntry(String entryName, InputStream inputStream) throws IOException { JarArchiveEntry entry = new JarArchiveEntry(entryName); writeEntry(entry, new InputStreamEntryWriter(inputStream, true)); } /** * Write a nested library. * @param destination 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); writeEntry(entry, new InputStreamEntryWriter(new FileInputStream(file), true), new LibraryUnpackHandler(library)); } private long getNestedLibraryTime(File file) { try { try (JarFile jarFile = new JarFile(file)) { Enumeration<JarEntry> entries = jarFile.entries(); while (entries.hasMoreElements()) { JarEntry entry = entries.nextElement(); if (!entry.isDirectory()) { return entry.getTime(); } } } } catch (Exception ex) { // Ignore and just use the source file timestamp } return file.lastModified(); } /** * Write the required spring-boot-loader classes to the JAR. * @throws IOException if the classes cannot be written */ @Override public void writeLoaderClasses() throws IOException { writeLoaderClasses(NESTED_LOADER_JAR); } /** * Write the required spring-boot-loader classes to the JAR. * @param loaderJarResourceName the name of the resource containing the loader classes * to be written * @throws IOException if the classes cannot be written */ @Override public void writeLoaderClasses(String loaderJarResourceName) throws IOException { URL loaderJar = getClass().getClassLoader().getResource(loaderJarResourceName); try (JarInputStream inputStream = new JarInputStream(new BufferedInputStream(loaderJar.openStream()))) { JarEntry entry; while ((entry = inputStream.getNextJarEntry()) != null) { if (entry.getName().endsWith(".class")) { writeEntry(new JarArchiveEntry(entry), new InputStreamEntryWriter(inputStream, false)); } } } } /** * Close the writer. * @throws IOException if the file cannot be closed */ @Override public void close() throws IOException { this.jarOutput.close(); } private void writeEntry(JarArchiveEntry entry, EntryWriter entryWriter) throws IOException { writeEntry(entry, entryWriter, NEVER_UNPACK); } /** * Perform the actual write of a {@link JarEntry}. All other write methods delegate to * this one. * @param entry the entry to write * @param entryWriter the entry writer or {@code null} if there is no content * @param unpackHandler handles possible unpacking for the entry * @throws IOException in case of I/O errors */ private void writeEntry(JarArchiveEntry entry, EntryWriter entryWriter, UnpackHandler unpackHandler) throws IOException { String parent = entry.getName(); if (parent.endsWith("/")) { parent = parent.substring(0, parent.length() - 1); entry.setUnixMode(UnixStat.DIR_FLAG | UnixStat.DEFAULT_DIR_PERM); } else { entry.setUnixMode(UnixStat.FILE_FLAG | UnixStat.DEFAULT_FILE_PERM); } if (parent.lastIndexOf('/') != -1) { parent = parent.substring(0, parent.lastIndexOf('/') + 1); if (!parent.isEmpty()) { writeEntry(new JarArchiveEntry(parent), null, unpackHandler); } } if (this.writtenEntries.add(entry.getName())) { entryWriter = addUnpackCommentIfNecessary(entry, entryWriter, unpackHandler); this.jarOutput.putArchiveEntry(entry); if (entryWriter != null) { entryWriter.write(this.jarOutput); } this.jarOutput.closeArchiveEntry(); } } private EntryWriter addUnpackCommentIfNecessary(JarArchiveEntry entry, EntryWriter entryWriter, UnpackHandler unpackHandler) throws IOException { if (entryWriter == null || !unpackHandler.requiresUnpack(entry.getName())) { return entryWriter; } ByteArrayOutputStream output = new ByteArrayOutputStream(); entryWriter.write(output); entry.setComment("UNPACK:" + unpackHandler.sha1Hash(entry.getName())); return new InputStreamEntryWriter(new ByteArrayInputStream(output.toByteArray()), true); } /** * Interface used to write jar entry date. */ private interface EntryWriter { /** * Write entry data to the specified output stream. * @param outputStream the destination for the data * @throws IOException in case of I/O errors */ void write(OutputStream outputStream) throws IOException; } /** * {@link EntryWriter} that writes content from an {@link InputStream}. */ private static class InputStreamEntryWriter implements EntryWriter { private final InputStream inputStream; private final boolean close; InputStreamEntryWriter(InputStream inputStream, boolean close) { this.inputStream = inputStream; this.close = close; } @Override public void write(OutputStream outputStream) throws IOException { byte[] buffer = new byte[BUFFER_SIZE]; int bytesRead; while ((bytesRead = this.inputStream.read(buffer)) != -1) { outputStream.write(buffer, 0, bytesRead); } outputStream.flush(); if (this.close) { this.inputStream.close(); } } } /** * {@link InputStream} that can peek ahead at zip header bytes. */ static class ZipHeaderPeekInputStream extends FilterInputStream { private static final byte[] ZIP_HEADER = new byte[] { 0x50, 0x4b, 0x03, 0x04 }; private final byte[] header; private final int headerLength; private int position; private ByteArrayInputStream headerStream; protected ZipHeaderPeekInputStream(InputStream in) throws IOException { super(in); this.header = new byte[4]; this.headerLength = in.read(this.header); this.headerStream = new ByteArrayInputStream(this.header, 0, this.headerLength); } @Override public int read() throws IOException { int read = (this.headerStream != null) ? this.headerStream.read() : -1; if (read != -1) { this.position++; if (this.position >= this.headerLength) { this.headerStream = null; } return read; } return super.read(); } @Override public int read(byte[] b) throws IOException { return read(b, 0, b.length); } @Override public int read(byte[] b, int off, int len) throws IOException { int read = (this.headerStream != null) ? this.headerStream.read(b, off, len) : -1; if (read <= 0) { return readRemainder(b, off, len); } this.position += read; if (read < len) { int remainderRead = readRemainder(b, off + read, len - read); if (remainderRead > 0) { read += remainderRead; } } if (this.position >= this.headerLength) { this.headerStream = null; } return read; } public boolean hasZipHeader() { return Arrays.equals(this.header, ZIP_HEADER); } private int readRemainder(byte[] b, int off, int len) throws IOException { int read = super.read(b, off, len); if (read > 0) { this.position += read; } return read; } } /** * Data holder for CRC and Size. */ private static class CrcAndSize { private final CRC32 crc = new CRC32(); private long size; CrcAndSize(File file) throws IOException { try (FileInputStream inputStream = new FileInputStream(file)) { load(inputStream); } } CrcAndSize(InputStream inputStream) throws IOException { load(inputStream); } private void load(InputStream inputStream) throws IOException { byte[] buffer = new byte[BUFFER_SIZE]; int bytesRead; while ((bytesRead = inputStream.read(buffer)) != -1) { this.crc.update(buffer, 0, bytesRead); this.size += bytesRead; } } public void setupStoredEntry(JarArchiveEntry entry) { entry.setSize(this.size); entry.setCompressedSize(this.size); entry.setCrc(this.crc.getValue()); entry.setMethod(ZipEntry.STORED); } } /** * An {@code EntryTransformer} enables the transformation of {@link JarEntry jar * entries} during the writing process. */ interface EntryTransformer { JarArchiveEntry transform(JarArchiveEntry jarEntry); } /** * An {@code EntryTransformer} that returns the entry unchanged. */ private static final class IdentityEntryTransformer implements EntryTransformer { @Override public JarArchiveEntry transform(JarArchiveEntry jarEntry) { return jarEntry; } } /** * An {@code UnpackHandler} determines whether or not unpacking is required and * provides a SHA1 hash if required. */ interface UnpackHandler { boolean requiresUnpack(String name); String sha1Hash(String name) throws IOException; } private static final class NeverUnpackHandler implements UnpackHandler { @Override public boolean requiresUnpack(String name) { return false; } @Override public String sha1Hash(String name) { throw new UnsupportedOperationException(); } } private static final class LibraryUnpackHandler implements UnpackHandler { private final Library library; private LibraryUnpackHandler(Library library) { this.library = library; } @Override public boolean requiresUnpack(String name) { return this.library.isUnpackRequired(); } @Override public String sha1Hash(String name) throws IOException { return FileUtils.sha1Hash(this.library.getFile()); } } }