mitm.application.djigzo.james.matchers.AbstractEvaluateUser.java Source code

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Here is the source code for mitm.application.djigzo.james.matchers.AbstractEvaluateUser.java

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/*
 * Copyright (c) 2008-2011, Martijn Brinkers, Djigzo.
 * 
 * This file is part of Djigzo email encryption.
 *
 * Djigzo is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License 
 * version 3, 19 November 2007 as published by the Free Software 
 * Foundation.
 *
 * Djigzo 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public 
 * License along with Djigzo. If not, see <http://www.gnu.org/licenses/>
 *
 * Additional permission under GNU AGPL version 3 section 7
 * 
 * If you modify this Program, or any covered work, by linking or 
 * combining it with aspectjrt.jar, aspectjweaver.jar, tyrex-1.0.3.jar, 
 * freemarker.jar, dom4j.jar, mx4j-jmx.jar, mx4j-tools.jar, 
 * spice-classman-1.0.jar, spice-loggerstore-0.5.jar, spice-salt-0.8.jar, 
 * spice-xmlpolicy-1.0.jar, saaj-api-1.3.jar, saaj-impl-1.3.jar, 
 * wsdl4j-1.6.1.jar (or modified versions of these libraries), 
 * containing parts covered by the terms of Eclipse Public License, 
 * tyrex license, freemarker license, dom4j license, mx4j license,
 * Spice Software License, Common Development and Distribution License
 * (CDDL), Common Public License (CPL) the licensors of this Program grant 
 * you additional permission to convey the resulting work.
 */
package mitm.application.djigzo.james.matchers;

import java.util.Collection;

import javax.mail.MessagingException;

import mitm.application.djigzo.User;
import mitm.application.djigzo.james.MessageOriginatorIdentifier;
import mitm.application.djigzo.service.SystemServices;
import mitm.application.djigzo.workflow.UserWorkflow;
import mitm.common.hibernate.DatabaseActionExecutor;
import mitm.common.hibernate.DatabaseActionExecutorBuilder;
import mitm.common.hibernate.SessionManager;
import net.sourceforge.jeval.EvaluationException;
import net.sourceforge.jeval.Evaluator;
import net.sourceforge.jeval.VariableResolver;

import org.apache.commons.lang.text.StrBuilder;
import org.apache.mailet.Mail;
import org.apache.mailet.MailAddress;

public abstract class AbstractEvaluateUser extends AbstractContextAwareDjigzoMatcher {
    /*
     * The number of times a database action should be retried when a ConstraintViolation occurs
     */
    private final static int ACTION_RETRIES = 3;

    /*
     * manages database sessions
     */
    private SessionManager sessionManager;

    /*
     * Used for adding and retrieving users
     */
    private UserWorkflow userWorkflow;

    /*
     * Is used to identify the 'sender' (from or enveloped sender or...) of the message
     */
    private MessageOriginatorIdentifier messageOriginatorIdentifier;

    /*
     * Used to execute database actions in a transaction
     */
    private DatabaseActionExecutor actionExecutor;

    /*
     * The expression to evaluate
     */
    private String expression;

    protected abstract VariableResolver getVariableResolver(Mail mail, User user) throws MessagingException;

    @Override
    public void init() {
        getLogger().info("Initializing matcher: " + getMatcherName());

        sessionManager = SystemServices.getSessionManager();

        userWorkflow = SystemServices.getUserWorkflow();

        messageOriginatorIdentifier = SystemServices.getMessageOriginatorIdentifier();

        actionExecutor = DatabaseActionExecutorBuilder.createDatabaseActionExecutor(sessionManager);

        assert (actionExecutor != null);

        expression = getCondition();

        if (expression == null) {
            throw new IllegalArgumentException("Expression must be specified.");
        }

        StrBuilder sb = new StrBuilder();

        sb.append("Expression: ");
        sb.append(expression);

        getLogger().info(sb.toString());
    }

    /*
     * Note: Evaluator is not thread safe. 
     */
    private Evaluator getEvaluator() {
        Evaluator evaluator = new Evaluator();

        return evaluator;
    }

    protected Collection<MailAddress> getMatchingMailAddresses(final Mail mail,
            final Collection<MailAddress> mailAddresses) throws MessagingException {
        MailAddressMatcher.HasMatchEventHandler hasMatchEventHandler = new MailAddressMatcher.HasMatchEventHandler() {
            @Override
            public boolean hasMatch(final User user) throws MessagingException {
                return AbstractEvaluateUser.this.hasMatch(mail, user);
            }
        };

        MailAddressMatcher matcher = new MailAddressMatcher(sessionManager, userWorkflow, actionExecutor,
                hasMatchEventHandler, ACTION_RETRIES);

        return matcher.getMatchingMailAddresses(mailAddresses);
    }

    protected void addFunctions(Evaluator evaluator) {
        evaluator.putFunction(new ToFloatFunction());
        evaluator.putFunction(new IsMIMETypeFunction());
    }

    protected boolean hasMatch(Mail mail, User user) throws MessagingException {
        Evaluator evaluator = getEvaluator();

        addFunctions(evaluator);

        evaluator.setVariableResolver(getVariableResolver(mail, user));

        try {
            return evaluator.getBooleanResult(expression);
        } catch (EvaluationException e) {
            throw new MessagingException("expression cannot be evaluated.", e);
        }
    }

    protected SessionManager getSessionManager() {
        return sessionManager;
    }

    protected UserWorkflow getUserWorkflow() {
        return userWorkflow;
    }

    protected MessageOriginatorIdentifier getMessageOriginatorIdentifier() {
        return messageOriginatorIdentifier;
    }

    protected DatabaseActionExecutor getActionExecutor() {
        return actionExecutor;
    }

    protected String getExpression() {
        return expression;
    }
}