Merge branch 'gh-1119'

Improve fat JAR performance.

See gh-1119

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

@@ -44,4 +44,5 @@ public class JarLauncher extends ExecutableArchiveLauncher {
 	public static void main(String[] args) {
 		new JarLauncher().launch(args);
 	}
+
 }

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

@@ -32,4 +32,5 @@ public interface JavaAgentDetector {
 	 * @param url The url to examine
 	 */
 	public boolean isJavaAgentJar(URL url);
+
 }

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

@@ -25,6 +25,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.Enumeration;
 
+import org.springframework.boot.loader.jar.Handler;
 import org.springframework.boot.loader.jar.JarFile;
 
 /**
@@ -93,7 +94,6 @@ public class LaunchedURLClassLoader extends URLClassLoader {
 
 	@Override
 	public Enumeration<URL> getResources(String name) throws IOException {
-
 		if (this.rootClassLoader == null) {
 			return findResources(name);
 		}
@@ -116,6 +116,7 @@ public class LaunchedURLClassLoader extends URLClassLoader {
 				}
 				return localResources.nextElement();
 			}
+
 		};
 	}
 
@@ -128,7 +129,13 @@ public class LaunchedURLClassLoader extends URLClassLoader {
 		synchronized (this) {
 			Class<?> loadedClass = findLoadedClass(name);
 			if (loadedClass == null) {
-				loadedClass = doLoadClass(name);
+				Handler.setUseFastConnectionExceptions(true);
+				try {
+					loadedClass = doLoadClass(name);
+				}
+				finally {
+					Handler.setUseFastConnectionExceptions(false);
+				}
 			}
 			if (resolve) {
 				resolveClass(loadedClass);
@@ -214,4 +221,5 @@ public class LaunchedURLClassLoader extends URLClassLoader {
 			// Ignore
 		}
 	}
+
 }

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

@@ -79,4 +79,5 @@ public class WarLauncher extends ExecutableArchiveLauncher {
 	public static void main(String[] args) {
 		new WarLauncher().launch(args);
 	}
+
 }

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/data/RandomAccessData.java

@@ -65,5 +65,7 @@ public interface RandomAccessData {
 		 * Obtain access to the underlying resource on each read, releasing it when done.
 		 */
 		PER_READ
+
 	}
+
 }

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/data/RandomAccessDataFile.java

@@ -221,6 +221,7 @@ public class RandomAccessDataFile implements RandomAccessData {
 			this.position += amount;
 			return amount;
 		}
+
 	}
 
 	/**
@@ -277,5 +278,7 @@ public class RandomAccessDataFile implements RandomAccessData {
 				throw new IOException(ex);
 			}
 		}
+
 	}
+
 }

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

@@ -76,4 +76,5 @@ class Bytes {
 		}
 		return value;
 	}
+
 }

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

@@ -119,4 +119,5 @@ class CentralDirectoryEndRecord {
 	public int getNumberOfRecords() {
 		return (int) Bytes.littleEndianValue(this.block, this.offset + 10, 2);
 	}
+
 }

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

@@ -18,11 +18,14 @@ package org.springframework.boot.loader.jar;
 
 import java.io.File;
 import java.io.IOException;
+import java.lang.ref.SoftReference;
 import java.lang.reflect.Method;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLConnection;
 import java.net.URLStreamHandler;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -39,7 +42,7 @@ public class Handler extends URLStreamHandler {
 
 	private static final String FILE_PROTOCOL = "file:";
 
-	private static final String SEPARATOR = JarURLConnection.SEPARATOR;
+	private static final String SEPARATOR = "!/";
 
 	private static final String[] FALLBACK_HANDLERS = { "sun.net.www.protocol.jar.Handler" };
 
@@ -55,6 +58,11 @@ public class Handler extends URLStreamHandler {
 		OPEN_CONNECTION_METHOD = method;
 	}
 
+	private static SoftReference<Map<File, JarFile>> rootFileCache;
+	static {
+		rootFileCache = new SoftReference<Map<File, JarFile>>(null);
+	}
+
 	private final Logger logger = Logger.getLogger(getClass().getName());
 
 	private final JarFile jarFile;
@@ -153,7 +161,14 @@ public class Handler extends URLStreamHandler {
 				throw new IllegalStateException("Not a file URL");
 			}
 			String path = name.substring(FILE_PROTOCOL.length());
-			return new JarFile(new File(path));
+			File file = new File(path);
+			Map<File, JarFile> cache = rootFileCache.get();
+			JarFile jarFile = (cache == null ? null : cache.get(file));
+			if (jarFile == null) {
+				jarFile = new JarFile(file);
+				addToRootFileCache(file, jarFile);
+			}
+			return jarFile;
 		}
 		catch (Exception ex) {
 			throw new IOException("Unable to open root Jar file '" + name + "'", ex);
@@ -168,4 +183,29 @@ public class Handler extends URLStreamHandler {
 		}
 		return jarFile.getNestedJarFile(jarEntry);
 	}
+
+	/**
+	 * Add the given {@link JarFile} to the root file cache.
+	 * @param sourceFile the source file to add
+	 * @param jarFile the jar file.
+	 */
+	static void addToRootFileCache(File sourceFile, JarFile jarFile) {
+		Map<File, JarFile> cache = rootFileCache.get();
+		if (cache == null) {
+			cache = new ConcurrentHashMap<File, JarFile>();
+			rootFileCache = new SoftReference<Map<File, JarFile>>(cache);
+		}
+		cache.put(sourceFile, jarFile);
+	}
+
+	/**
+	 * Set if a generic static exception can be thrown when a URL cannot be connected.
+	 * This optimization is used during class loading to save creating lots of exceptions
+	 * which are then swallowed.
+	 * @param useFastConnectionExceptions if fast connection exceptions can be used.
+	 */
+	public static void setUseFastConnectionExceptions(boolean useFastConnectionExceptions) {
+		JarURLConnection.setUseFastExceptions(useFastConnectionExceptions);
+	}
+
 }

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

@@ -53,22 +53,30 @@ public final class JarEntryData {
 
 	private SoftReference<JarEntry> entry;
 
+	JarFile nestedJar;
+
 	public JarEntryData(JarFile source, byte[] header, InputStream inputStream)
 			throws IOException {
-
 		this.source = source;
 		this.header = header;
 		long nameLength = Bytes.littleEndianValue(header, 28, 2);
 		long extraLength = Bytes.littleEndianValue(header, 30, 2);
 		long commentLength = Bytes.littleEndianValue(header, 32, 2);
-
 		this.name = new AsciiBytes(Bytes.get(inputStream, nameLength));
 		this.extra = Bytes.get(inputStream, extraLength);
 		this.comment = new AsciiBytes(Bytes.get(inputStream, commentLength));
-
 		this.localHeaderOffset = Bytes.littleEndianValue(header, 42, 4);
 	}
 
+	private JarEntryData(JarEntryData master, JarFile source, AsciiBytes name) {
+		this.header = master.header;
+		this.extra = master.extra;
+		this.comment = master.comment;
+		this.localHeaderOffset = master.localHeaderOffset;
+		this.source = source;
+		this.name = name;
+	}
+
 	void setName(AsciiBytes name) {
 		this.name = name;
 	}
@@ -154,6 +162,10 @@ public final class JarEntryData {
 		return this.comment;
 	}
 
+	JarEntryData createFilteredCopy(JarFile jarFile, AsciiBytes name) {
+		return new JarEntryData(this, jarFile, name);
+	}
+
 	/**
 	 * Create a new {@link JarEntryData} instance from the specified input stream.
 	 * @param source the source {@link JarFile}

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

@@ -22,6 +22,8 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.net.URLConnection;
+import java.net.URLStreamHandler;
 import java.util.jar.Manifest;
 
 import org.springframework.boot.loader.util.AsciiBytes;
@@ -33,51 +35,73 @@ import org.springframework.boot.loader.util.AsciiBytes;
  */
 class JarURLConnection extends java.net.JarURLConnection {
 
-	static final String PROTOCOL = "jar";
+	private static final FileNotFoundException FILE_NOT_FOUND_EXCEPTION = new FileNotFoundException();
 
-	static final String SEPARATOR = "!/";
+	private static final String SEPARATOR = "!/";
 
-	private static final String PREFIX = PROTOCOL + ":" + "file:";
+	private static final URL EMPTY_JAR_URL;
 
-	private final JarFile jarFile;
+	static {
+		try {
+			EMPTY_JAR_URL = new URL("jar:", null, 0, "file:!/", new URLStreamHandler() {
+				@Override
+				protected URLConnection openConnection(URL u) throws IOException {
+					// Stub URLStreamHandler to prevent the wrong JAR Handler from being
+					// Instantiated and cached.
+					return null;
+				}
+			});
+		}
+		catch (MalformedURLException ex) {
+			throw new IllegalStateException(ex);
+		}
+	}
 
-	private JarEntryData jarEntryData;
+	private static final JarEntryName EMPTY_JAR_ENTRY_NAME = new JarEntryName("");
 
-	private String jarEntryName;
+	private static ThreadLocal<Boolean> useFastExceptions = new ThreadLocal<Boolean>();
 
-	private String contentType;
+	private final String jarFileUrlSpec;
+
+	private final JarFile jarFile;
+
+	private JarEntryData jarEntryData;
 
 	private URL jarFileUrl;
 
+	private JarEntryName jarEntryName;
+
 	protected JarURLConnection(URL url, JarFile jarFile) throws MalformedURLException {
-		super(new URL(buildRootUrl(jarFile)));
+		// What we pass to super is ultimately ignored
+		super(EMPTY_JAR_URL);
 		this.url = url;
 		this.jarFile = jarFile;
-
 		String spec = url.getFile();
 		int separator = spec.lastIndexOf(SEPARATOR);
 		if (separator == -1) {
 			throw new MalformedURLException("no " + SEPARATOR + " found in url spec:"
 					+ spec);
 		}
-		if (separator + 2 != spec.length()) {
-			this.jarEntryName = decode(spec.substring(separator + 2));
-		}
+		this.jarFileUrlSpec = spec.substring(0, separator);
+		this.jarEntryName = getJarEntryName(spec.substring(separator + 2));
+	}
 
-		String container = spec.substring(0, separator);
-		if (container.indexOf(SEPARATOR) == -1) {
-			this.jarFileUrl = new URL(container);
-		}
-		else {
-			this.jarFileUrl = new URL("jar:" + container);
+	private JarEntryName getJarEntryName(String spec) {
+		if (spec.length() == 0) {
+			return EMPTY_JAR_ENTRY_NAME;
 		}
+		return new JarEntryName(spec);
 	}
 
 	@Override
 	public void connect() throws IOException {
-		if (this.jarEntryName != null) {
-			this.jarEntryData = this.jarFile.getJarEntryData(this.jarEntryName);
+		if (!this.jarEntryName.isEmpty()) {
+			this.jarEntryData = this.jarFile.getJarEntryData(this.jarEntryName
+					.asAsciiBytes());
 			if (this.jarEntryData == null) {
+				if (Boolean.TRUE.equals(useFastExceptions.get())) {
+					throw FILE_NOT_FOUND_EXCEPTION;
+				}
 				throw new FileNotFoundException("JAR entry " + this.jarEntryName
 						+ " not found in " + this.jarFile.getName());
 			}
@@ -103,9 +127,24 @@ class JarURLConnection extends java.net.JarURLConnection {
 
 	@Override
 	public URL getJarFileURL() {
+		if (this.jarFileUrl == null) {
+			this.jarFileUrl = buildJarFileUrl();
+		}
 		return this.jarFileUrl;
 	}
 
+	private URL buildJarFileUrl() {
+		try {
+			if (this.jarFileUrlSpec.indexOf(SEPARATOR) == -1) {
+				return new URL(this.jarFileUrlSpec);
+			}
+			return new URL("jar:" + this.jarFileUrlSpec);
+		}
+		catch (MalformedURLException ex) {
+			throw new IllegalStateException(ex);
+		}
+	}
+
 	@Override
 	public JarEntry getJarEntry() throws IOException {
 		connect();
@@ -114,13 +153,13 @@ class JarURLConnection extends java.net.JarURLConnection {
 
 	@Override
 	public String getEntryName() {
-		return this.jarEntryName;
+		return this.jarEntryName.toString();
 	}
 
 	@Override
 	public InputStream getInputStream() throws IOException {
 		connect();
-		if (this.jarEntryName == null) {
+		if (this.jarEntryName.isEmpty()) {
 			throw new IOException("no entry name specified");
 		}
 		return this.jarEntryData.getInputStream();
@@ -130,8 +169,10 @@ class JarURLConnection extends java.net.JarURLConnection {
 	public int getContentLength() {
 		try {
 			connect();
-			return this.jarEntryData == null ? this.jarFile.size() : this.jarEntryData
-					.getSize();
+			if (this.jarEntryData != null) {
+				return this.jarEntryData.getSize();
+			}
+			return this.jarFile.size();
 		}
 		catch (IOException ex) {
 			return -1;
@@ -146,58 +187,86 @@ class JarURLConnection extends java.net.JarURLConnection {
 
 	@Override
 	public String getContentType() {
-		if (this.contentType == null) {
-			// Guess the content type, don't bother with steams as mark is not
-			// supported
-			this.contentType = (this.jarEntryName == null ? "x-java/jar" : null);
-			this.contentType = (this.contentType == null ? guessContentTypeFromName(this.jarEntryName)
-					: this.contentType);
-			this.contentType = (this.contentType == null ? "content/unknown"
-					: this.contentType);
-		}
-		return this.contentType;
-	}
-
-	private static String buildRootUrl(JarFile jarFile) {
-		String path = jarFile.getRootJarFile().getFile().getPath();
-		StringBuilder builder = new StringBuilder(PREFIX.length() + path.length()
-				+ SEPARATOR.length());
-		builder.append(PREFIX);
-		builder.append(path);
-		builder.append(SEPARATOR);
-		return builder.toString();
-	}
-
-	private static String decode(String source) {
-		int length = source.length();
-		if ((length == 0) || (source.indexOf('%') < 0)) {
-			return source;
-		}
-		ByteArrayOutputStream bos = new ByteArrayOutputStream(length);
-		for (int i = 0; i < length; i++) {
-			int ch = source.charAt(i);
-			if (ch == '%') {
-				if ((i + 2) >= length) {
-					throw new IllegalArgumentException("Invalid encoded sequence \""
-							+ source.substring(i) + "\"");
+		return this.jarEntryName.getContentType();
+	}
+
+	static void setUseFastExceptions(boolean useFastExceptions) {
+		JarURLConnection.useFastExceptions.set(useFastExceptions);
+	}
+
+	/**
+	 * A JarEntryName parsed from a URL String.
+	 */
+	private static class JarEntryName {
+
+		private final AsciiBytes name;
+
+		private String contentType;
+
+		public JarEntryName(String spec) {
+			this.name = decode(spec);
+		}
+
+		private AsciiBytes decode(String source) {
+			int length = (source == null ? 0 : source.length());
+			if ((length == 0) || (source.indexOf('%') < 0)) {
+				return new AsciiBytes(source);
+			}
+			ByteArrayOutputStream bos = new ByteArrayOutputStream(length);
+			for (int i = 0; i < length; i++) {
+				int ch = source.charAt(i);
+				if (ch == '%') {
+					if ((i + 2) >= length) {
+						throw new IllegalArgumentException("Invalid encoded sequence \""
+								+ source.substring(i) + "\"");
+					}
+					ch = decodeEscapeSequence(source, i);
+					i += 2;
 				}
-				ch = decodeEscapeSequence(source, i);
-				i += 2;
+				bos.write(ch);
 			}
-			bos.write(ch);
+			// AsciiBytes is what is used to store the JarEntries so make it symmetric
+			return new AsciiBytes(bos.toByteArray());
 		}
-		// AsciiBytes is what is used to store the JarEntries so make it symmetric
-		return new AsciiBytes(bos.toByteArray()).toString();
 
-	}
+		private char decodeEscapeSequence(String source, int i) {
+			int hi = Character.digit(source.charAt(i + 1), 16);
+			int lo = Character.digit(source.charAt(i + 2), 16);
+			if (hi == -1 || lo == -1) {
+				throw new IllegalArgumentException("Invalid encoded sequence \""
+						+ source.substring(i) + "\"");
+			}
+			return ((char) ((hi << 4) + lo));
+		}
+
+		@Override
+		public String toString() {
+			return this.name.toString();
+		}
+
+		public AsciiBytes asAsciiBytes() {
+			return this.name;
+		}
+
+		public boolean isEmpty() {
+			return this.name.length() == 0;
+		}
+
+		public String getContentType() {
+			if (this.contentType == null) {
+				this.contentType = deduceContentType();
+			}
+			return this.contentType;
+		}
 
-	private static char decodeEscapeSequence(String source, int i) {
-		int hi = Character.digit(source.charAt(i + 1), 16);
-		int lo = Character.digit(source.charAt(i + 2), 16);
-		if (hi == -1 || lo == -1) {
-			throw new IllegalArgumentException("Invalid encoded sequence \""
-					+ source.substring(i) + "\"");
+		private String deduceContentType() {
+			// Guess the content type, don't bother with streams as mark is not supported
+			String type = (isEmpty() ? "x-java/jar" : null);
+			type = (type != null ? type : guessContentTypeFromName(toString()));
+			type = (type != null ? type : "content/unknown");
+			return type;
 		}
-		return ((char) ((hi << 4) + lo));
+
 	}
+
 }

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/util/AsciiBytes.java

@@ -128,6 +128,13 @@ public final class AsciiBytes {
 		return append(string.getBytes(UTF_8));
 	}
 
+	public AsciiBytes append(AsciiBytes asciiBytes) {
+		if (asciiBytes == null || asciiBytes.length() == 0) {
+			return this;
+		}
+		return append(asciiBytes.bytes);
+	}
+
 	public AsciiBytes append(byte[] bytes) {
 		if (bytes == null || bytes.length == 0) {
 			return this;