RMIClassLoader.java [plain text]
package java.rmi.server;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.Map;
import java.util.StringTokenizer;
public class RMIClassLoader
{
private RMIClassLoader() {}
private static class MyClassLoader extends URLClassLoader
{
MyClassLoader (URL[] urls, ClassLoader parent, String annotation)
{
super (urls, parent);
this.annotation = annotation;
}
private MyClassLoader (URL[] urls, ClassLoader parent)
{
super (urls, parent);
this.annotation = urlToAnnotation (urls);
}
public static String urlToAnnotation (URL[] urls)
{
if (urls.length == 0)
return null;
StringBuffer annotation = new StringBuffer (64 * urls.length);
for (int i = 0; i < urls.length; i++)
{
annotation.append (urls [i].toExternalForm());
annotation.append (' ');
}
return annotation.toString();
}
public final String getClassAnnotation()
{
return annotation;
}
private final String annotation;
}
private static class CacheKey
{
private String mCodeBase;
private ClassLoader mContextClassLoader;
public CacheKey (String theCodebase, ClassLoader theContextClassLoader)
{
mCodeBase = theCodebase;
mContextClassLoader = theContextClassLoader;
}
public boolean equals (Object theOther)
{
if (theOther instanceof CacheKey)
{
CacheKey key = (CacheKey) theOther;
return (equals (this.mCodeBase,key.mCodeBase)
&& equals (this.mContextClassLoader, key.mContextClassLoader));
}
return false;
}
private boolean equals (Object theOne, Object theOther)
{
return theOne != null ? theOne.equals (theOther) : theOther == null;
}
public int hashCode()
{
return ((mCodeBase != null ? mCodeBase.hashCode() : 0)
^(mContextClassLoader != null ? mContextClassLoader.hashCode() : -1));
}
public String toString()
{
return "[" + mCodeBase + "," + mContextClassLoader + "]";
}
}
private static Map cacheLoaders; private static Map cacheAnnotations;
private static String defaultAnnotation;
private static URL defaultCodebase;
private static MyClassLoader defaultLoader;
static
{
cacheLoaders = new Hashtable (89);
cacheAnnotations = new Hashtable (89);
defaultAnnotation = System.getProperty ("java.rmi.server.defaultAnnotation");
try
{
if (defaultAnnotation != null)
defaultCodebase = new URL (defaultAnnotation);
}
catch (Exception _)
{
defaultCodebase = null;
}
if (defaultCodebase != null)
{
defaultLoader = new MyClassLoader (new URL[] { defaultCodebase }, null,
defaultAnnotation);
cacheLoaders.put (new CacheKey (defaultAnnotation,
Thread.currentThread().getContextClassLoader()),
defaultLoader);
}
}
public static Class loadClass (String name)
throws MalformedURLException, ClassNotFoundException
{
return loadClass ("", name);
}
public static Class loadClass (String codebases, String name)
throws MalformedURLException, ClassNotFoundException
{
ClassLoader loader = Thread.currentThread().getContextClassLoader();
try
{
return loader.loadClass (name);
}
catch (ClassNotFoundException e)
{
}
if (codebases.length() == 0) {
loader = defaultLoader;
}
else
{
loader = getClassLoader(codebases);
}
if (loader == null)
{
throw new ClassNotFoundException ("Could not find class (" + name +
") at codebase (" + codebases + ")");
}
return loader.loadClass (name);
}
private static ClassLoader getClassLoader (String codebases)
throws MalformedURLException
{
ClassLoader loader;
CacheKey loaderKey = new CacheKey
(codebases, Thread.currentThread().getContextClassLoader());
loader = (ClassLoader) cacheLoaders.get (loaderKey);
if (loader == null)
{
StringTokenizer tok = new StringTokenizer (codebases, " ");
ArrayList urls = new ArrayList();
while (tok.hasMoreTokens())
urls.add (new URL (tok.nextToken()));
loader = new MyClassLoader ((URL[]) urls.toArray (new URL [urls.size()]),
Thread.currentThread().getContextClassLoader(),
codebases);
cacheLoaders.put (loaderKey, loader);
}
return loader;
}
public static String getClassAnnotation (Class cl)
{
ClassLoader loader = cl.getClassLoader();
if (loader == null
|| loader == ClassLoader.getSystemClassLoader())
{
return System.getProperty ("java.rmi.server.codebase");
}
if (loader instanceof MyClassLoader)
{
return ((MyClassLoader) loader).getClassAnnotation();
}
String s = (String) cacheAnnotations.get (loader);
if (s != null)
return s;
if (loader instanceof URLClassLoader)
{
URL[] urls = ((URLClassLoader) loader).getURLs();
if (urls.length == 0)
return null;
StringBuffer annotation = new StringBuffer (64 * urls.length);
for (int i = 0; i < urls.length; i++)
{
annotation.append (urls [i].toExternalForm());
annotation.append (' ');
}
s = annotation.toString();
cacheAnnotations.put (loader, s);
return s;
}
return System.getProperty ("java.rmi.server.codebase");
}
public static Object getSecurityContext (ClassLoader loader)
{
throw new Error ("Not implemented");
}
}