This utility class allows for initialization of all classes * at startup to avoid initialization delays at an innapropriate time.
* *Note: Users might want to disable logging when initializing run-time * classes at start-up because of the presence of old classes (never used) * in the jar files for which initialization fails. For example:[code] * public static main(String[] args) { * LogContext.enter(LogContext.NULL); // Temporarely disables logging errors and warnings. * try { * ClassInitializer.initializeAll(); // Initializes bootstrap, extensions and classpath classes. * } finally { * LogContext.exit(LogContext.NULL); // Goes back to default logging. * } * ... * }[/code]
* * @author Jean-Marie Dautelle * @version 3.6, November 6, 2005 */ public class ClassInitializer { /** * Default constructor (private for utility class) */ private ClassInitializer() { } /** * Initializes all runtime and classpath classes. * * @see #initializeRuntime() * @see #initializeClassPath() */ public static void initializeAll() { initializeRuntime(); initializeClassPath(); } /** * Initializes runtime classes (bootstrap classes in
* System.getProperty("sun.boot.class.path")) and the
* extension .jar in lib/ext directory).
*/
public static void initializeRuntime() {
String bootPath = System.getProperty("sun.boot.class.path");
String pathSeparator = System.getProperty("path.separator");
if ((bootPath == null) || (pathSeparator == null)) {
StandardLog
.warning("Cannot initialize boot path through system properties");
return;
}
initialize(bootPath, pathSeparator);
String javaHome = System.getProperty("java.home");
String fileSeparator = System.getProperty("file.separator");
if ((javaHome == null) || (fileSeparator == null)) {
StandardLog
.warning("Cannot initialize extension library through system properties");
return;
}
File extDir = new File(javaHome + fileSeparator + "lib" + fileSeparator
+ "ext");
if (!extDir.getClass().getName().equals("java.io.File")) {
StandardLog
.warning("Extension classes initialization not supported for J2ME build");
return;
}
if (extDir.isDirectory()) {
File[] files = extDir.listFiles();
for (int i = 0; i < files.length; i++) {
String path = files[i].getPath();
if (path.endsWith(".jar") || path.endsWith(".zip")) {
initializeJar(path);
}
}
} else {
StandardLog.warning(extDir + " is not a directory");
}
}
/**
* Initializes all classes in current classpath.
*/
public static void initializeClassPath() {
String classPath = System.getProperty("java.class.path");
String pathSeparator = System.getProperty("path.separator");
if ((classPath == null) || (pathSeparator == null)) {
StandardLog
.warning("Cannot initialize classpath through system properties");
return;
}
initialize(classPath, pathSeparator);
}
private static void initialize(String classPath, String pathSeparator) {
StandardLog.fine("Initialize classpath: " + classPath);
while (classPath.length() > 0) {
String name;
int index = classPath.indexOf(pathSeparator);
if (index < 0) {
name = classPath;
classPath = "";
} else {
name = classPath.substring(0, index);
classPath = classPath.substring(index + pathSeparator.length());
}
if (name.endsWith(".jar") || name.endsWith(".zip")) {
initializeJar(name);
} else {
initializeDir(name);
}
}
}
/**
* Initializes the specified class.
*
* @param cls the class to initialize.
*/
public static void initialize(Class cls) {
try {
Reflection.getClass(cls.getName());
} catch (Exception error) {
StandardLog.error(error);
}
}
/**
* Initializes the class with the specified name.
*
* @param className the name of the class to initialize.
*/
public static void initialize(String className) {
try {
Reflection.getClass(className);
} catch (ClassNotFoundException e) {
StandardLog.warning("Class + " + className + " not found");
} catch (Exception error) {
StandardLog.error(error);
}
}
/**
* Initializes all the classes in the specified jar file.
*
* @param jarName the jar filename.
*/
public static void initializeJar(String jarName) {
try {
StandardLog.fine("Initialize Jar file: " + jarName);
ZipFile jarFile = new ZipFile(jarName);
if (!jarFile.getClass().getName().equals("java.util.zip.ZipFile")) {
StandardLog
.warning("Initialization of classes in jar file not supported for J2ME build");
return;
}
Enumeration e = jarFile.entries();
while (e.hasMoreElements()) {
ZipEntry entry = (ZipEntry) e.nextElement();
String entryName = entry.getName();
if (entryName.endsWith(".class")) {
String className = entryName.substring(0, entryName
.length() - 6);
className = className.replace('/', '.');
StandardLog.finer("Initialize " + className);
ClassInitializer.initialize(className);
}
}
} catch (Exception e) {
StandardLog.error(e);
}
}
/**
* Initializes all the classes in the specified directory.
*
* @param dirName the name of the directory containing the classes to
* initialize.
*/
public static void initializeDir(String dirName) {
StandardLog.fine("Initialize Directory: " + dirName);
File file = new File(dirName);
if (!file.getClass().getName().equals("java.io.File")) {
StandardLog
.warning("Initialization of classes in directory not supported for J2ME build");
return;
}
if (file.isDirectory()) {
File[] files = file.listFiles();
for (int i = 0; i < files.length; i++) {
initialize("", files[i]);
}
} else {
StandardLog.warning(dirName + " is not a directory");
}
}
private static void initialize(String prefix, File file) {
String name = file.getName();
if (file.isDirectory()) {
File[] files = file.listFiles();
String newPrefix = (prefix.length() == 0) ? name : prefix + "."
+ name;
for (int i = 0; i < files.length; i++) {
initialize(newPrefix, files[i]);
}
} else {
if (name.endsWith(".class")) {
String className = prefix + "."
+ name.substring(0, name.length() - 6);
StandardLog.finer("Initialize " + className);
ClassInitializer.initialize(className);
}
}
}
}