org.springframework.ldap.control.AbstractRequestControlDirContextProcessor Maven / Gradle / Ivy

/*
 * Copyright 2005-2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.ldap.control;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.ldap.core.DirContextProcessor;

import javax.naming.NamingException;
import javax.naming.directory.DirContext;
import javax.naming.ldap.Control;
import javax.naming.ldap.LdapContext;

/**
 * Abstract superclass with responsibility to apply a single RequestControl on
 * an LdapContext, preserving any existing controls. Subclasses should implement
 * {@link DirContextProcessor#postProcess(DirContext)} and template method
 * {@link #createRequestControl()}.
 * 
 * @author Mattias Hellborg Arthursson
 * @author Ulrik Sandberg
 */
public abstract class AbstractRequestControlDirContextProcessor implements DirContextProcessor {
	protected Logger log = LoggerFactory.getLogger(AbstractRequestControlDirContextProcessor.class);

	private boolean replaceSameControlEnabled = true;

	/**
	 * If there already exists a request control of the same class as the one
	 * created by {@link #createRequestControl()} in the context, the new
	 * control can either replace the existing one (default behavior) or be
	 * added.
	 * 
	 * @return true if an already existing control will be replaced
	 */
	public boolean isReplaceSameControlEnabled() {
		return replaceSameControlEnabled;
	}

	/**
	 * If there already exists a request control of the same class as the one
	 * created by {@link #createRequestControl()} in the context, the new
	 * control can either replace the existing one (default behavior) or be
	 * added.
	 * 
	 * @param replaceSameControlEnabled true if an already
	 * existing control should be replaced
	 */
	public void setReplaceSameControlEnabled(boolean replaceSameControlEnabled) {
		this.replaceSameControlEnabled = replaceSameControlEnabled;
	}

	/**
	 * Get the existing RequestControls from the LdapContext, call
	 * {@link #createRequestControl()} to get a new instance, build a new array
	 * of Controls and set it on the LdapContext.
	 * 
	 * The {@link Control} feature is specific for LDAP v3 and thus applies only
	 * to {@link LdapContext}. However, the generic DirContextProcessor
	 * mechanism used for calling preProcess and
	 * postProcess uses DirContext, since it also works for LDAP
	 * v2. This is the reason that DirContext has to be cast to a LdapContext.
	 * 
	 * @param ctx an LdapContext instance.
	 * @throws NamingException
	 * @throws IllegalArgumentException if the supplied DirContext is not an
	 * LdapContext.
	 */
	public void preProcess(DirContext ctx) throws NamingException {
		LdapContext ldapContext;
		if (ctx instanceof LdapContext) {
			ldapContext = (LdapContext) ctx;
		}
		else {
			throw new IllegalArgumentException("Request Control operations require LDAPv3 - "
					+ "Context must be of type LdapContext");
		}

		Control[] requestControls = ldapContext.getRequestControls();
		if (requestControls == null) {
			requestControls = new Control[0];
		}
		Control newControl = createRequestControl();

		Control[] newControls = new Control[requestControls.length + 1];
		for (int i = 0; i < requestControls.length; i++) {
			if (replaceSameControlEnabled && requestControls[i].getClass() == newControl.getClass()) {
				log.debug("Replacing already existing control in context: " + newControl);
				requestControls[i] = newControl;
				ldapContext.setRequestControls(requestControls);
				return;
			}
			newControls[i] = requestControls[i];
		}

		// Add the new Control at the end of the array.
		newControls[newControls.length - 1] = newControl;

		ldapContext.setRequestControls(newControls);
	}

	/**
	 * Create an instance of the appropriate RequestControl.
	 * 
	 * @return the new instance.
	 */
	public abstract Control createRequestControl();
}