Glassfish example source code file (ConstraintField.java)

This example Glassfish source code file (ConstraintField.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Glassfish tags/keywords

constraintfield, field, http, httpservletrequest, illegalargumentexception, log, logger, logging, object, request, response, scope_names, scope_names, servlet, string, string, the, the, valueconstraint, valueconstraint

The Glassfish ConstraintField.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package com.sun.appserv.web.cache.mapping;

import com.sun.logging.LogDomains;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import java.util.logging.Level;
import java.util.logging.Logger;

/** ConstraintField class represents a single Field and constraints on its 
 *  values; Field name and its scope are inherited from the Field class. 
 */
public class ConstraintField extends Field {

    private static final String[] SCOPE_NAMES = {
        "", "context.attribute", "request.header", "request.parameter",
        "request.cookie", "request.attribute", "session.attribute",
        "session.id"
    };

    private static final Logger _logger = LogDomains.getLogger(
        ConstraintField.class, LogDomains.WEB_LOGGER);

    private static final boolean _isTraceEnabled =
        _logger.isLoggable(Level.FINE);

    // whether to cache if there was a match
    boolean cacheOnMatch = true;
    // whether to cache if there was a failure to match
    boolean cacheOnMatchFailure = false;

    // field value constraints 
    ValueConstraint constraints[] = new ValueConstraint[0];

    /**
     * create a new cache field, given a string representation of the scope
     * @param name name of this field
     * @param scope scope of this field
     */
    public ConstraintField(String name, String scope) 
            throws IllegalArgumentException {
        super(name, scope);
    }

    /** set whether to cache should the constraints check pass
     * @param cacheOnMatch should the constraint check pass, should we cache?
     */
    public void setCacheOnMatch(boolean cacheOnMatch) {
        this.cacheOnMatch = cacheOnMatch;
    }

    /**
     * @return cache-on-match setting
     */
    public boolean getCacheOnMatch() {
        return cacheOnMatch;
    }

    /** set whether to cache should there be a failure forcing the constraint
     * @param cacheOnMatchFailure should there be a constraint check failure,
     *  enable cache?
     */
    public void setCacheOnMatchFailure(boolean cacheOnMatchFailure) {
        this.cacheOnMatchFailure = cacheOnMatchFailure;
    }

    /**
     * @return cache-on-match-failure setting
     */
    public boolean getCacheOnMatchFailure() {
        return cacheOnMatchFailure;
    }

    /**
     * add a constraint for this field
     * @param constraint one constraint associated with this field
     */
    public void addConstraint(ValueConstraint constraint) {
        if (constraint == null)
            return;

        ValueConstraint results[] = 
            new ValueConstraint[constraints.length + 1];
        for (int i = 0; i < constraints.length; i++)
            results[i] = constraints[i];

        results[constraints.length] = constraint;
        constraints = results;
    }

    /**
     * add an array of constraints for this field
     * @param vcs constraints associated with this field
     */
    public void setValueConstraints(ValueConstraint[] vcs) {
        if (vcs == null)
            return;

        constraints = vcs;
    }

    /** apply the constraints on the value of the field in the given request.
     *  return a true if all the constraints pass; false when the 
     *  field is not found or the field value doesn't pass the caching 
     *  constraints. 
     */ 
    public boolean applyConstraints(ServletContext context,
                                    HttpServletRequest request) {

        Object value = getValue(context, request);
        if (value == null) {
            // the field is not present in the request
            if (_isTraceEnabled) {
                _logger.fine(
                    "The constraint field " + name
                    + " is not found in the scope " + SCOPE_NAMES[scope]
                    + "; returning cache-on-match-failure: "
                    + cacheOnMatchFailure);
            }
            return cacheOnMatchFailure;
        } else if (constraints.length == 0) {
            // the field is present but has no value constraints
            if (_isTraceEnabled) {
                _logger.fine(
                    "The constraint field " + name + " value = "
                    + value.toString() + " is found in scope "
                    + SCOPE_NAMES[scope] + "; returning cache-on-match: "
                    + cacheOnMatch);
            }
            return cacheOnMatch;
        }

        // apply all the value constraints
        for (int i = 0; i < constraints.length; i++) {
            ValueConstraint c = constraints[i];

            // one of the values matched
            if (c.matches(value)) {
                if (_isTraceEnabled) {
                    _logger.fine(
                        "The constraint field " + name + " value = "
                        + value.toString() + " is found in scope "
                        + SCOPE_NAMES[scope] + "; and matches with a value "
                        + c.toString() + "; returning cache-on-match: "
                        + cacheOnMatch);
            }
                return cacheOnMatch;
            }
        }

        // none of the values matched; should we cache?
        if (_isTraceEnabled) {
            _logger.fine(
                "The constraint field " + name + " value = "
                + value.toString() + " is found in scope " + SCOPE_NAMES[scope]
                + "; but didn't match any of the value constraints; "
                + "returning cache-on-match-failure = "
                + cacheOnMatchFailure);
        }
        return cacheOnMatchFailure;
    }
}