org.esigate.url.StickySessionBaseUrlRetrieveStrategy.java Source code

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Here is the source code for org.esigate.url.StickySessionBaseUrlRetrieveStrategy.java

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/* 
 * 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 org.esigate.url;

import org.apache.http.cookie.Cookie;
import org.apache.http.impl.cookie.BasicClientCookie;
import org.esigate.api.BaseUrlRetrieveStrategy;
import org.esigate.http.IncomingRequest;

public class StickySessionBaseUrlRetrieveStrategy implements BaseUrlRetrieveStrategy {
    public static final String ESI_SESSION_COOKIE_NAME = "_esigate_session_cookie";
    private final String[] urls;

    public StickySessionBaseUrlRetrieveStrategy(String[] urls) {
        super();
        this.urls = urls;
    }

    private int generateIndex() {
        return (int) (Math.random() * this.urls.length);
    }

    @Override
    public String getBaseURL(IncomingRequest originalRequest) {
        Cookie sessionCookie = getEsiSessionCookie(originalRequest.getCookies());
        int index = 0;
        boolean toGenerate = true;

        if (null != sessionCookie) {
            toGenerate = false;
            String indexStr = sessionCookie.getValue();

            if (null != indexStr) {
                try {
                    Integer indexInt = Integer.parseInt(indexStr);
                    index = indexInt.intValue();
                } catch (Exception e) {
                    index = -1;
                }
                if (index < 0 || index >= this.urls.length) {
                    toGenerate = true;
                }
            } else {
                toGenerate = true;
            }
        }
        if (toGenerate) {
            index = generateIndex();
            Cookie cookie = new BasicClientCookie(ESI_SESSION_COOKIE_NAME, Integer.toString(index));
            originalRequest.addNewCookie(cookie);
        }

        return this.urls[index];
    }

    private Cookie getEsiSessionCookie(Cookie[] cookies) {
        Cookie ret = null;
        if (null != cookies && cookies.length > 0) {
            for (Cookie cookie : cookies) {
                if (ESI_SESSION_COOKIE_NAME.equals(cookie.getName())) {
                    ret = cookie;
                    break;
                }
            }
        }
        return ret;
    }

}