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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
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*
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package com.sun.jndi.url.dns;
import java.util.Hashtable;
import javax.naming.*;
import javax.naming.spi.ObjectFactory;
/**
* A DNS URL context factory creates contexts that can resolve names
* that are DNS pseudo-URLs.
* In addition, if given a specific DNS URL (or an array of them), the
* factory will resolve all the way to the named context.
* See com.sun.jndi.dns.DnsUrl for a description of the URL format.
*
* @author Scott Seligman
*/
public class dnsURLContextFactory implements ObjectFactory {
public Object getObjectInstance(Object urlInfo, Name name,
Context nameCtx, Hashtable<?,?> env)
throws NamingException {
if (urlInfo == null) {
return (new dnsURLContext(env));
} else if (urlInfo instanceof String) {
return getUsingURL((String) urlInfo, env);
} else if (urlInfo instanceof String[]) {
return getUsingURLs((String[]) urlInfo, env);
} else {
throw (new ConfigurationException(
"dnsURLContextFactory.getObjectInstance: " +
"argument must be a DNS URL String or an array of them"));
}
}
private static Object getUsingURL(String url, Hashtable env)
throws NamingException {
dnsURLContext urlCtx = new dnsURLContext(env);
try {
return urlCtx.lookup(url);
} finally {
urlCtx.close();
}
}
/*
* Try each URL until lookup() succeeds for one of them.
* If all URLs fail, throw one of the exceptions arbitrarily.
* Not pretty, but potentially more informative than returning null.
*/
private static Object getUsingURLs(String[] urls, Hashtable env)
throws NamingException {
if (urls.length == 0) {
throw (new ConfigurationException(
"dnsURLContextFactory: empty URL array"));
}
dnsURLContext urlCtx = new dnsURLContext(env);
try {
NamingException ne = null;
for (int i = 0; i < urls.length; i++) {
try {
return urlCtx.lookup(urls[i]);
} catch (NamingException e) {
ne = e;
}
}
throw ne; // failure: throw one of the exceptions caught
} finally {
urlCtx.close();
}
}
}