/**
* Loads class from a JAR and searches for all jar-in-jar.
*
* @param sClassName class to load.
* @return Loaded class.
* @throws JarClassLoaderException.
*/
private Class<?> findJarClass(String sClassName) throws JarClassLoaderException {
// http://java.sun.com/developer/onlineTraining/Security/Fundamentals
// /magercises/ClassLoader/solution/FileClassLoader.java
Class<?> c = hmClass.get(sClassName);
if (c != null) {
return c;
}
// Char '/' works for Win32 and Unix.
String sName = sClassName.replace('.', '/') + ".class";
JarEntryInfo inf = findJarEntry(sName);
String jarSimpleName = null;
if (inf != null) {
jarSimpleName = inf.jarFileInfo.simpleName;
definePackage(sClassName, inf);
byte[] a_by = inf.getJarBytes();
try {
c = defineClass(sClassName, a_by, 0, a_by.length, pd);
} catch (ClassFormatError e) {
throw new JarClassLoaderException(null, e);
}
}
if (c == null) {
throw new JarClassLoaderException(sClassName);
}
hmClass.put(sClassName, c);
logInfo(
LogArea.CLASS,
"Loaded %s by %s from JAR %s",
sClassName,
getClass().getName(),
jarSimpleName);
return c;
} // findJarClass()
/**
* Using temp files (one per inner JAR/DLL) solves many issues: 1. There are no ways to load JAR
* defined in a JarEntry directly into the JarFile object (see also #6 below). 2. Cannot use
* memory-mapped files because they are using nio channels, which are not supported by JarFile
* ctor. 3. JarFile object keeps opened JAR files handlers for fast access. 4. Deep resource in a
* jar-in-jar does not have well defined URL. Making temp file with JAR solves this problem. 5.
* Similar issues with native libraries: <code>ClassLoader.findLibrary()</code> accepts ONLY
* string with absolute path to the file with native library. 6. Option
* "java.protocol.handler.pkgs" does not allow access to nested JARs(?).
*
* @param inf JAR entry information.
* @return temporary file object presenting JAR entry.
* @throws JarClassLoaderException
*/
private File createTempFile(JarEntryInfo inf) throws JarClassLoaderException {
// Temp files directory:
// WinXP: C:/Documents and Settings/username/Local Settings/Temp/JarClassLoader
// Unix: /var/tmp/JarClassLoader
if (dirTemp == null) {
File dir = new File(System.getProperty("java.io.tmpdir"), TMP_SUB_DIRECTORY);
if (!dir.exists()) {
dir.mkdir();
}
chmod777(dir); // Unix - allow temp directory RW access to all users.
if (!dir.exists() || !dir.isDirectory()) {
throw new JarClassLoaderException("Cannot create temp directory " + dir.getAbsolutePath());
}
dirTemp = dir;
}
File fileTmp = null;
try {
fileTmp = File.createTempFile(inf.getName() + ".", null, dirTemp);
fileTmp.deleteOnExit();
chmod777(fileTmp); // Unix - allow temp file deletion by any user
byte[] a_by = inf.getJarBytes();
BufferedOutputStream os = new BufferedOutputStream(new FileOutputStream(fileTmp));
os.write(a_by);
os.close();
return fileTmp;
} catch (IOException e) {
throw new JarClassLoaderException(
String.format("Cannot create temp file '%s' for %s", fileTmp, inf.jarEntry), e);
}
} // createTempFile()