edu.vt.middleware.ldap.handler.AbstractResultHandler.java Source code

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Here is the source code for edu.vt.middleware.ldap.handler.AbstractResultHandler.java

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/*
  $Id$
    
  Copyright (C) 2003-2010 Virginia Tech.
  All rights reserved.
    
  SEE LICENSE FOR MORE INFORMATION
    
  Author:  Middleware Services
  Email:   middleware@vt.edu
  Version: $Revision$
  Updated: $Date$
*/
package edu.vt.middleware.ldap.handler;

import java.util.ArrayList;
import java.util.List;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * <code>AbstractResultHandler</code> implements common handler functionality.
 *
 * @param  <R>  type of result
 * @param  <O>  type of output
 *
 * @author  Middleware Services
 * @version  $Revision$ $Date$
 */
public abstract class AbstractResultHandler<R, O> implements ResultHandler<R, O> {

    /** Log for this class. */
    protected final Log logger = LogFactory.getLog(this.getClass());

    /**
     * This will enumerate through the supplied <code>NamingEnumeration</code> and
     * return a List of those results. The results are unaltered and the dn is
     * ignored.
     *
     * @param  sc  <code>SearchCriteria</code> used to find enumeration
     * @param  en  <code>NamingEnumeration</code> LDAP results
     *
     * @return  <code>List</code> - LDAP results
     *
     * @throws  NamingException  if the LDAP returns an error
     */
    public List<O> process(final SearchCriteria sc, final NamingEnumeration<? extends R> en)
            throws NamingException {
        return this.process(sc, en, null);
    }

    /**
     * This will enumerate through the supplied <code>NamingEnumeration</code> and
     * return a List of those results. The results are unaltered and the dn is
     * ignored. Any exceptions passed into this method will be ignored and results
     * will be returned as if no exception occurred.
     *
     * @param  sc  <code>SearchCriteria</code> used to find enumeration
     * @param  en  <code>NamingEnumeration</code> LDAP results
     * @param  ignore  <code>Class[]</code> of exception types to ignore
     *
     * @return  <code>List</code> - LDAP results
     *
     * @throws  NamingException  if the LDAP returns an error
     */
    public List<O> process(final SearchCriteria sc, final NamingEnumeration<? extends R> en,
            final Class<?>[] ignore) throws NamingException {
        final List<O> results = new ArrayList<O>();
        if (en != null) {
            try {
                while (en.hasMore()) {
                    final O o = processResult(sc, en.next());
                    if (o != null) {
                        results.add(o);
                    }
                }
            } catch (NamingException e) {
                boolean ignoreException = false;
                if (ignore != null && ignore.length > 0) {
                    for (Class<?> ne : ignore) {
                        if (ne.isInstance(e)) {
                            if (this.logger.isDebugEnabled()) {
                                this.logger.debug("Ignoring naming exception", e);
                            }
                            ignoreException = true;
                            break;
                        }
                    }
                }
                if (!ignoreException) {
                    throw e;
                }
            }
        }
        return results;
    }

    /**
     * This will enumerate through the supplied <code>List</code> and return a
     * List of those results. The results are unaltered and the dn is ignored.
     *
     * @param  sc  <code>SearchCriteria</code> used to find enumeration
     * @param  l  <code>List</code> LDAP results
     *
     * @return  <code>List</code> - LDAP results
     *
     * @throws  NamingException  if the LDAP returns an error
     */
    public List<O> process(final SearchCriteria sc, final List<? extends R> l) throws NamingException {
        final List<O> results = new ArrayList<O>();
        if (l != null) {
            for (R r : l) {
                final O o = processResult(sc, r);
                if (o != null) {
                    results.add(o);
                }
            }
        }
        return results;
    }

    /**
     * Processes the supplied result.
     *
     * @param  sc  <code>SearchCriteria</code> used to retrieve the result
     * @param  r  <code>R</code> result to process
     *
     * @return  <code>O</code> processed result
     *
     * @throws  NamingException  if the supplied result cannot be read
     */
    protected abstract O processResult(final SearchCriteria sc, final R r) throws NamingException;
}