com.isotrol.impe3.core.impl.RequestParamsFactory.java Source code

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Here is the source code for com.isotrol.impe3.core.impl.RequestParamsFactory.java

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/**
 * This file is part of Port@l
 * Port@l 3.0 - Portal Engine and Management System
 * Copyright (C) 2010  Isotrol, SA.  http://www.isotrol.com
 *
 * Port@l is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Port@l 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Port@l.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.isotrol.impe3.core.impl;

import java.util.Arrays;
import java.util.Enumeration;
import java.util.List;
import java.util.Set;
import java.util.Map.Entry;

import javax.servlet.ServletRequest;
import javax.ws.rs.core.UriInfo;

import net.sf.derquinsej.CaseIgnoringString;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMultimap;
import com.google.common.collect.Multimap;
import com.isotrol.impe3.api.RequestParams;

/**
 * Factory class for different HTTP request parameters implementations.
 * @author Andres Rodriguez
 */
public final class RequestParamsFactory {
    /** Not instantiable. */
    private RequestParamsFactory() {
        throw new AssertionError();
    }

    private static final Empty EMPTY = new Empty();

    /**
     * Returns an empty collection of cookies.
     */
    public static RequestParams of() {
        return EMPTY;
    }

    /**
     * Adds the parameters from a servlet request.
     * @param request Servlet request.
     * @return The request parameters.
     */
    public static RequestParams of(ServletRequest request) {
        Preconditions.checkNotNull(request, "The request cannot be null.");
        final ImmutableMultimap.Builder<CaseIgnoringString, String> builder = ImmutableMultimap.builder();
        @SuppressWarnings("unchecked")
        final Enumeration<String> names = request.getParameterNames();
        if (names != null) {
            while (names.hasMoreElements()) {
                final String parameter = names.nextElement();
                final String[] values = request.getParameterValues(parameter);
                if (values != null && values.length > 0) {
                    builder.putAll(CaseIgnoringString.valueOf(parameter), Arrays.asList(values));
                }
            }
        }
        return new Immutable(builder.build());
    }

    /**
     * Returns the collection of request parameters from a JAX-RS headers object.
     * @param info URI information.
     * @return The request query parameters.
     */
    public static RequestParams of(UriInfo info) {
        Preconditions.checkNotNull(info, "The URI object cannot be null.");
        final ImmutableMultimap.Builder<CaseIgnoringString, String> builder = ImmutableMultimap.builder();
        for (Entry<String, List<String>> entry : info.getQueryParameters().entrySet()) {
            List<String> values = entry.getValue();
            if (values != null) {
                builder.putAll(CaseIgnoringString.valueOf(entry.getKey()), values);
            }
        }
        return new Immutable(builder.build());
    }

    /**
     * Returns the collection of request parameters from a multimap object.
     * @param map Multimap.
     * @return The request query parameters.
     */
    public static RequestParams of(Multimap<String, String> map) {
        if (map == null || map.isEmpty()) {
            return EMPTY;
        }
        final ImmutableMultimap.Builder<CaseIgnoringString, String> builder = ImmutableMultimap.builder();
        for (String key : map.keySet()) {
            final CaseIgnoringString cis = CaseIgnoringString.valueOf(key);
            builder.putAll(cis, map.get(key));
        }
        return new Immutable(builder.build());
    }

    /**
     * Empty implementation.
     * @author Andres Rodriguez
     */
    private static final class Empty extends EmptyMultiStringParameters implements RequestParams {
        private Empty() {
        }

        public RequestParams subset(Set<String> included) {
            return this;
        }
    }

    /**
     * Immutable HTTP request params implementation.
     * @author Andres Rodriguez
     */
    private static final class Immutable extends AbstractMultiStringParameters.AbstractImmutable
            implements RequestParams {
        private Immutable(Multimap<CaseIgnoringString, String> parameters) {
            super(parameters);
        }

        public RequestParams subset(Set<String> included) {
            return new Immutable(submap(included));
        }
    }

}