001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 * 
010 *      http://www.apache.org/licenses/LICENSE-2.0
011 * 
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.oozie.service;
019
020import org.apache.oozie.service.Service;
021import org.apache.oozie.service.Services;
022import org.apache.oozie.util.ParamChecker;
023import org.apache.hadoop.conf.Configuration;
024
025import java.io.UnsupportedEncodingException;
026import java.net.URLDecoder;
027import java.text.MessageFormat;
028
029/**
030 * Service that generates and parses callback URLs.
031 */
032public class CallbackService implements Service {
033
034    public static final String CONF_PREFIX = Service.CONF_PREFIX + "CallbackService.";
035
036    public static final String CONF_BASE_URL = CONF_PREFIX + "base.url";
037
038    private Configuration oozieConf;
039
040    /**
041     * Initialize the service.
042     *
043     * @param services services instance.
044     */
045    public void init(Services services) {
046        oozieConf = services.getConf();
047    }
048
049    /**
050     * Destroy the service.
051     */
052    public void destroy() {
053    }
054
055    /**
056     * Return the public interface of the Dag engine service.
057     *
058     * @return {@link CallbackService}.
059     */
060    public Class<? extends Service> getInterface() {
061        return CallbackService.class;
062    }
063
064    private static final String ID_PARAM = "id=";
065    private static final String STATUS_PARAM = "status=";
066    private static final String CALL_BACK_QUERY_STRING = "{0}?" + ID_PARAM + "{1}" + "&" + STATUS_PARAM + "{2}";
067
068    /**
069     * Create a callback URL.
070     *
071     * @param actionId action ID for the callback URL.
072     * @param externalStatusVar variable for the caller to inject the external status.
073     * @return the callback URL.
074     */
075    public String createCallBackUrl(String actionId, String externalStatusVar) {
076        ParamChecker.notEmpty(actionId, "actionId");
077        ParamChecker.notEmpty(externalStatusVar, "externalStatusVar");
078        //TODO: figure out why double encoding is happening in case of hadoop callbacks.
079        String baseCallbackUrl = oozieConf.get(CONF_BASE_URL, "http://localhost:8080/oozie/v0/callback");
080        return MessageFormat.format(CALL_BACK_QUERY_STRING, baseCallbackUrl, actionId, externalStatusVar);
081    }
082
083    private String getParam(String str, String name) {
084        String value = null;
085        int start = str.indexOf(name);
086        if (start > -1) {
087            int end = str.indexOf("&", start + 1);
088            start = start + name.length();
089            value = (end > -1) ? str.substring(start, end) : str.substring(start);
090        }
091        return value;
092    }
093
094    /**
095     * Return if a callback URL is valid or not.
096     *
097     * @param callback callback URL (it can be just the callback portion of it).
098     * @return <code>true</code> if the callback URL is valid, <code>false</code> if it is not.
099     */
100    public boolean isValid(String callback) {
101        return callback != null && getParam(callback, ID_PARAM) != null && getParam(callback, STATUS_PARAM) != null;
102    }
103
104    /**
105     * Return the action ID from a callback URL.
106     *
107     * @param callback callback URL (it can be just the callback portion of it).
108     * @return the action ID from a callback URL.
109     */
110    public String getActionId(String callback) {
111        try {
112            return URLDecoder.decode(getParam(ParamChecker.notEmpty(callback, "callback"), ID_PARAM), "UTF-8");
113        }
114        catch (UnsupportedEncodingException ex) {
115            throw new RuntimeException(ex);
116        }
117    }
118
119    /**
120     * Return the action external status from a callback URL.
121     *
122     * @param callback callback URL (it can be just the callback portion of it).
123     * @return the action external status from a callback URL.
124     */
125    public String getExternalStatus(String callback) {
126        try {
127            return URLDecoder.decode(getParam(ParamChecker.notEmpty(callback, "callback"), STATUS_PARAM), "UTF-8");
128        }
129        catch (UnsupportedEncodingException ex) {
130            throw new RuntimeException(ex);
131        }
132    }
133
134}