SearchResultToAttrValueList.java

/*
 * This program is free software; you can redistribute it and/or modify it under the 
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software 
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this 
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html 
 * or from the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * This program 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 Lesser General Public License for more details.
 *
 * Copyright 2007 - 2009 Pentaho Corporation.  All rights reserved.
 *
 */
package org.pentaho.platform.plugin.services.security.userrole.ldap.transform;

import java.util.HashSet;
import java.util.Set;

import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attribute;
import javax.naming.directory.SearchResult;

import org.apache.commons.collections.Transformer;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.pentaho.platform.plugin.services.messages.Messages;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;

/**
 * Extracts the value of the token <code>tokenName</code> from the attribute
 * <code>attributeName</code>. Ignores attribute value if value is not of
 * type <code>String</code>. Returns the entire attribute value if
 * <code>tokenName</code> is not specified.
 * <p>
 * <strong>Note: This transformer can produce more than one output (in the form
 * of a collection) per single input. Any client of this class should merge the
 * results (e.g. <code>collection.addAll(collection)</code>) into an existing
 * collection.</strong>
 * </p>
 * 
 * <p>
 * Transformer input: <code>SearchResult</code> instance
 * </p>
 * <p>
 * Transformer output: <code>Collection</code> of <code>String</code>
 * instances
 * </p>
 * TODO refactor into searchresulttoattributelist,
 * attributelisttosingleattribute, attributestringtoattributesubstring
 * 
 * @author mlowery
 */
public class SearchResultToAttrValueList implements Transformer, InitializingBean {

  // ~ Static fields/initializers ============================================
  private static final Log logger = LogFactory.getLog(SearchResultToAttrValueList.class);

  // ~ Instance fields =======================================================

  private String attributeName;

  private String tokenName;

  // ~ Constructors ==========================================================

  public SearchResultToAttrValueList(final String attributeName) {
    this(attributeName, null);
  }

  public SearchResultToAttrValueList(final String attributeName, final String tokenName) {
    super();
    this.attributeName = attributeName;
    this.tokenName = tokenName;
  }

  // ~ Methods ===============================================================

  /**
   * Assumes that <code>src</code> consists of name-value pairs linked via
   * <code>'='</code> and each pair separated by <code>','</code>.
   * 
   * @param src
   *            the source string
   * @param inTokenName
   *            the name part of the name-value pair whose value will be
   *            returned
   * @return the value part of the name-value pair whose name part is
   *         <code>tokenName</code>
   */
  protected String extract(final String src, final String inTokenName) {
    if (SearchResultToAttrValueList.logger.isDebugEnabled()) {
      SearchResultToAttrValueList.logger.debug(Messages.getInstance().getString(
          "SearchResultToAttrValueList.DEBUG_LOOKING_FOR_SUBSTRING", inTokenName, src)); //$NON-NLS-1$
    }
    String[] tokens = src.split(","); //$NON-NLS-1$
    for (String rdnString : tokens) {
      String[] rdnTokens = rdnString.split("="); //$NON-NLS-1$
      if (rdnTokens[0].trim().equals(inTokenName)) {
        if (SearchResultToAttrValueList.logger.isDebugEnabled()) {
          SearchResultToAttrValueList.logger.debug(Messages.getInstance().getString(
              "SearchResultToAttrValueList.DEBUG_EXTRACTED_TOKEN", rdnTokens[1].trim())); //$NON-NLS-1$
        }
        return rdnTokens[1].trim();
      }
    }
    if (SearchResultToAttrValueList.logger.isDebugEnabled()) {
      SearchResultToAttrValueList.logger.debug(Messages.getInstance().getString(
          "SearchResultToAttrValueList.DEBUG_TOKEN_NOT_FOUND", inTokenName, src)); //$NON-NLS-1$
    }
    return null;
  }

  public void afterPropertiesSet() throws Exception {
    Assert.hasLength(attributeName);
  }

  public Object transform(final Object obj) {
    Object transformed = obj;
    if (obj instanceof SearchResult) {
      transformed = new HashSet();
      Set valueSet = (Set) transformed;
      SearchResult res = (SearchResult) obj;
      if (SearchResultToAttrValueList.logger.isDebugEnabled()) {
        SearchResultToAttrValueList.logger
            .debug(Messages.getInstance()
                .getString(
                    "SearchResultToAttrValueList.DEBUG_ATTRIBUTES_FROM_SEARCHRESULT", (null != res.getAttributes()) ? res.getAttributes().toString() : "null")); //$NON-NLS-1$ //$NON-NLS-2$
      }
      Attribute attr = res.getAttributes().get(attributeName);
      if (SearchResultToAttrValueList.logger.isDebugEnabled()) {
        SearchResultToAttrValueList.logger
            .debug(Messages.getInstance()
                .getString(
                    "SearchResultToAttrValueList.DEBUG_ATTRIBUTE_VALUE", attributeName, (null != attr) ? attr.toString() : "null")); //$NON-NLS-1$ //$NON-NLS-2$
      }
      if (attr != null) { // check for null as node might not have attribute we're looking for
        try {
          NamingEnumeration values = attr.getAll();
          while (values.hasMore()) {
            // if tokenName was specified, extract from value; otherwise
            // store value unchanged
            Object value = values.next();
            if (StringUtils.hasLength(tokenName)) {
              if ((null != value) && (value instanceof String)) {
                String tokenValue = extract((String) value, tokenName);
                if (null != tokenValue) {
                  valueSet.add(tokenValue);
                }
              } else {
                if (SearchResultToAttrValueList.logger.isWarnEnabled()) {
                  SearchResultToAttrValueList.logger.warn(Messages.getInstance()
                      .getString("SearchResultToAttrValueList.WARN_ATTRIBUTE_NOT_A_STRING")); //$NON-NLS-1$
                }
              }
            } else {
              if (null != value) {
                valueSet.add(value.toString());
              }
            }
          }
        } catch (NamingException e) {
          if (SearchResultToAttrValueList.logger.isErrorEnabled()) {
            SearchResultToAttrValueList.logger.error(Messages.getInstance()
                .getErrorString("SearchResultToAttrValueList.ERROR_0001_NAMING_EXCEPTION"), e); //$NON-NLS-1$
          }
        }
      }
      return transformed;

    }
    return transformed;

  }
}