DolphinScheduler/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/template/impl/DefaultHTMLTemplate.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.dolphinscheduler.alert.template.impl;

import org.apache.dolphinscheduler.alert.template.AlertTemplate;
import org.apache.dolphinscheduler.alert.utils.Constants;
import org.apache.dolphinscheduler.alert.utils.JSONUtils;
import org.apache.dolphinscheduler.common.enums.ShowType;
import org.apache.dolphinscheduler.common.utils.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.*;

import static org.apache.dolphinscheduler.common.utils.Preconditions.*;

/**
 * the default html alert message template
 */
public class DefaultHTMLTemplate implements AlertTemplate {

    public static final Logger logger = LoggerFactory.getLogger(DefaultHTMLTemplate.class);


    @Override
    public String getMessageFromTemplate(String content, ShowType showType,boolean showAll) {

        switch (showType){
            case TABLE:
                return getTableTypeMessage(content,showAll);
            case TEXT:
                return getTextTypeMessage(content,showAll);
            default:
                throw new IllegalArgumentException(String.format("not support showType: %s in DefaultHTMLTemplate",showType));
        }
    }

    /**
     * get alert message which type is TABLE
     * @param content message content
     * @param showAll weather to show all
     * @return alert message
     */
    private String getTableTypeMessage(String content,boolean showAll){

        if (StringUtils.isNotEmpty(content)){
            List<LinkedHashMap> mapItemsList = JSONUtils.toList(content, LinkedHashMap.class);

            if(!showAll && mapItemsList.size() > Constants.NUMBER_1000){
                mapItemsList = mapItemsList.subList(0,Constants.NUMBER_1000);
            }

            StringBuilder contents = new StringBuilder(200);

            boolean flag = true;

            String title = "";
            for (LinkedHashMap mapItems : mapItemsList){

                Set<Map.Entry<String, Object>> entries = mapItems.entrySet();

                Iterator<Map.Entry<String, Object>> iterator = entries.iterator();

                StringBuilder t = new StringBuilder(Constants.TR);
                StringBuilder cs = new StringBuilder(Constants.TR);
                while (iterator.hasNext()){

                    Map.Entry<String, Object> entry = iterator.next();
                    t.append(Constants.TH).append(entry.getKey()).append(Constants.TH_END);
                    cs.append(Constants.TD).append(String.valueOf(entry.getValue())).append(Constants.TD_END);

                }
                t.append(Constants.TR_END);
                cs.append(Constants.TR_END);
                if (flag){
                    title = t.toString();
                }
                flag = false;
                contents.append(cs);
            }

            return getMessageFromHtmlTemplate(title,contents.toString());
        }

        return content;
    }

    /**
     * get alert message which type is TEXT
     * @param content message content
     * @param showAll weather to show all
     * @return alert message
     */
    private String getTextTypeMessage(String content,boolean showAll){

        if (StringUtils.isNotEmpty(content)){
            List<String> list;
            try {
                list = JSONUtils.toList(content,String.class);
            }catch (Exception e){
                logger.error("json format exception",e);
                return null;
            }

            StringBuilder contents = new StringBuilder(100);
            for (String str : list){
                contents.append(Constants.TR);
                contents.append(Constants.TD).append(str).append(Constants.TD_END);
                contents.append(Constants.TR_END);
            }

            return getMessageFromHtmlTemplate(null,contents.toString());

        }

        return content;
    }

    /**
     * get alert message from a html template
     * @param title     message title
     * @param content   message content
     * @return alert message which use html template
     */
    private String getMessageFromHtmlTemplate(String title,String content){

        checkNotNull(content);
        String htmlTableThead = StringUtils.isEmpty(title) ? "" : String.format("<thead>%s</thead>\n",title);

        return Constants.HTML_HEADER_PREFIX +htmlTableThead + content + Constants.TABLE_BODY_HTML_TAIL;
    }

}