com.minlia.cloud.framework.test.common.web.util.HTTPLinkHeaderUtil.java Source code

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Here is the source code for com.minlia.cloud.framework.test.common.web.util.HTTPLinkHeaderUtil.java

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/**
 * Copyright (C) 2004-2015 http://oss.minlia.com/license/framework/2015
 *
 * 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
 *
 *       http://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 com.minlia.cloud.framework.test.common.web.util;

import java.util.List;

import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;

public final class HTTPLinkHeaderUtil {

    private HTTPLinkHeaderUtil() {
        throw new AssertionError();
    }

    //

    /**
     * ex. <br>
     * https://api.github.com/users/steveklabnik/gists?page=2>; rel="next", <https://api.github.com/users/steveklabnik/gists?page=3>; rel="last"
     */
    public static List<String> extractAllURIs(final String linkHeader) {
        Preconditions.checkNotNull(linkHeader);

        final List<String> linkHeaders = Lists.newArrayList();
        final String[] links = linkHeader.split(", ");
        for (final String link : links) {
            final int positionOfSeparator = link.indexOf(';');
            linkHeaders.add(link.substring(1, positionOfSeparator - 1));
        }

        return linkHeaders;
    }

    public static String extractURIByRel(final String linkHeader, final String rel) {
        Preconditions.checkNotNull(linkHeader);

        String uriWithSpecifiedRel = null;
        final String[] links = linkHeader.split(", ");
        String linkRelation = null;
        for (final String link : links) {
            final int positionOfSeparator = link.indexOf(';');
            linkRelation = link.substring(positionOfSeparator + 1, link.length()).trim();
            if (extractTypeOfRelation(linkRelation).equals(rel)) {
                uriWithSpecifiedRel = link.substring(1, positionOfSeparator - 1);
                break;
            }
        }

        return uriWithSpecifiedRel;
    }

    static Object extractTypeOfRelation(final String linkRelation) {
        final int positionOfEquals = linkRelation.indexOf('=');
        return linkRelation.substring(positionOfEquals + 2, linkRelation.length() - 1).trim();
    }

    /**
     * ex. <br>
     * https://api.github.com/users/steveklabnik/gists?page=2>; rel="next"
     */
    public static String extractSingleURI(final String linkHeader) {
        Preconditions.checkNotNull(linkHeader);
        final int positionOfSeparator = linkHeader.indexOf(';');

        return linkHeader.substring(1, positionOfSeparator - 1);
    }

}