Reflection, or “A Class Named Class” - Java - page 929

final final String packageAsDirName = packageName . replace ( "." , "/" );

final

final List < String > list = new new ArrayList <>();

final final Enumeration < URL > urls =

Thread . currentThread ().
getContextClassLoader ().
getResources ( packageAsDirName );

while while ( urls . hasMoreElements ()) {

URL url = urls . nextElement ();
// System.out.println("URL = " + url);
String file = url . getFile ();
switch

switch ( url . getProtocol ()) {
case

case "file" :
// This is the easy case: "file" is
// the full path to the classpath directory
File dir = new new File ( file );

for for ( File f : dir . listFiles ()) {

list . add ( packageAsDirName + "/" + f . getName ());

}
break break ;

case case "jar" :

// This is the harder case; "file" is of the form
// "jar:/home/ian/bleah/darwinsys.jar!com/darwinsys/io"
// for some jar file that contains at least one class from
// the given package.
int int colon = file . indexOf ( ':' );

int int bang = file . indexOf ( '!' );

String jarFileName = file . substring ( colon + 1 , bang );
JarFile jarFile = new new JarFile ( jarFileName );

Enumeration < JarEntry > entries = jarFile . entries ();
while

while ( entries . hasMoreElements ()) {
JarEntry e = entries . nextElement ();
String jarEntryName = e . getName ();
iif (! jarEntryName . endsWith ( "/" ) &&
jarEntryName . startsWith ( packageAsDirName )) {
list . add ( jarEntryName );

}

}
break

break ;
default default :

throw

throw new new IllegalStateException (

"Dunno what to do with URL " + url );

}

}
return return list . toArray ( new new String [] {});

}