Merge branch 'gh-1119'

Improve fat JAR performance.

See gh-1119

Author: Phillip Webb

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

@@ -44,4 +44,5 @@ protected void postProcessClassPathArchives(List<Archive> archives) throws Excep
 	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.Collections;
 import java.util.Enumeration;
 
+import org.springframework.boot.loader.jar.Handler;
 import org.springframework.boot.loader.jar.JarFile;
 
 /**
@@ -93,7 +94,6 @@ private boolean hasURLs() {
 
 	@Override
 	public Enumeration<URL> getResources(String name) throws IOException {
-
 		if (this.rootClassLoader == null) {
 			return findResources(name);
 		}
@@ -116,6 +116,7 @@ public URL nextElement() {
 				}
 				return localResources.nextElement();
 			}
+
 		};
 	}
 
@@ -128,7 +129,13 @@ protected Class<?> loadClass(String name, boolean resolve)
 		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 Object run() throws ClassNotFoundException {
 			// Ignore
 		}
 	}
+
 }

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

@@ -79,4 +79,5 @@ public AsciiBytes apply(AsciiBytes entryName, Archive.Entry entry) {
 	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 static enum ResourceAccess {
 		 * 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 @@ private long moveOn(int amount) {
 			this.position += amount;
 			return amount;
 		}
+
 	}
 
 	/**
@@ -277,5 +278,7 @@ public void close() throws IOException {
 				throw new IOException(ex);
 			}
 		}
+
 	}
+
 }

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

@@ -76,4 +76,5 @@ public static long littleEndianValue(byte[] bytes, int offset, int length) {
 		}
 		return value;
 	}
+
 }

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

@@ -119,4 +119,5 @@ public RandomAccessData getCentralDirectory(RandomAccessData data) {
 	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 @@
 
 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 @@ private JarFile getRootJarFile(String name) throws IOException {
 				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 @@ private JarFile getNestedJarFile(JarFile jarFile, String name) throws IOExceptio
 		}
 		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 AsciiBytes getComment() {
 		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}