Refactor alert template (apache#1713)

* refactor Alert Template

* refactor alert template(remove freemarker)

* add license

* update abstract class to interface

* make test into root pom

* fix powermock static

* fix powermock static

* remove custom exception

* remove custom exception

dolphinscheduler-alert/pom.xml

@@ -36,15 +36,34 @@
             <artifactId>junit</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <type>jar</type>
+            <scope>test</scope>
+        </dependency>
 
         <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-email</artifactId>
+            <groupId>org.powermock</groupId>
+            <artifactId>powermock-module-junit4</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.powermock</groupId>
+            <artifactId>powermock-api-mockito2</artifactId>
+            <scope>test</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.mockito</groupId>
+                    <artifactId>mockito-core</artifactId>
+                </exclusion>
+            </exclusions>
         </dependency>
 
         <dependency>
-            <groupId>org.freemarker</groupId>
-            <artifactId>freemarker</artifactId>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-email</artifactId>
         </dependency>
 
         <dependency>

dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/template/AlertTemplate.java

@@ -0,0 +1,41 @@
+/*
+ * 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;
+
+import org.apache.dolphinscheduler.common.enums.ShowType;
+
+/**
+ * alert message template
+ */
+public interface AlertTemplate {
+
+    /**
+     * get a message from a specified alert template
+     * @param content     alert message content
+     * @param showType    show type
+     * @param showAll    whether to show all
+     * @return a message from a specified alert template
+     */
+    String getMessageFromTemplate(String content, ShowType showType,boolean showAll);
+
+    /**
+     * default showAll is true
+     */
+    default String getMessageFromTemplate(String content,ShowType showType){
+        return getMessageFromTemplate(content,showType,true);
+    }
+}

dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/template/AlertTemplateFactory.java

@@ -0,0 +1,54 @@
+/*
+ * 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;
+
+import org.apache.dolphinscheduler.alert.template.impl.DefaultHTMLTemplate;
+import org.apache.dolphinscheduler.alert.utils.Constants;
+import org.apache.dolphinscheduler.alert.utils.PropertyUtils;
+import org.apache.dolphinscheduler.common.utils.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * the alert template factory
+ */
+public class AlertTemplateFactory {
+
+    private static final Logger logger = LoggerFactory.getLogger(AlertTemplateFactory.class);
+
+    private static final String alertTemplate = PropertyUtils.getString(Constants.ALERT_TEMPLATE);
+
+    private AlertTemplateFactory(){}
+
+    /**
+     * get a template from alert.properties conf file
+     * @return a template, default is DefaultHTMLTemplate
+     */
+    public static AlertTemplate getMessageTemplate() {
+
+        if(StringUtils.isEmpty(alertTemplate)){
+            return new DefaultHTMLTemplate();
+        }
+
+        switch (alertTemplate){
+            case "html":
+                return new DefaultHTMLTemplate();
+            default:
+                throw new IllegalArgumentException(String.format("not support alert template: %s",alertTemplate));
+        }
+    }
+}

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

@@ -0,0 +1,161 @@
+/*
+ * 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.alert.utils.MailUtils;
+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 "<html>\n" +
+                "    <head>\n" +
+                "        <title>dolphinscheduler</title>\n" +
+                "        <meta name='Keywords' content=''>\n" +
+                "        <meta name='Description' content=''>\n" +
+                "        <style type=\"text/css\">\n" +
+                "            table {margin-top:0px;padding-top:0px;border:1px solid;font-size: 14px;color: #333333;border-width: 1px;border-color: #666666;border-collapse: collapse;}\n" +
+                "            table th {border-width: 1px;padding: 8px;border-style: solid;border-color: #666666;background-color: #dedede;text-align: right;}\n" +
+                "            table td {border-width: 1px;padding: 8px;border-style: solid;border-color: #666666;background-color: #ffffff;text-align: right;}\n" +
+                "        </style>\n" +
+                "    </head>\n" +
+                "    <body style=\"margin:0;padding:0\">\n" +
+                "        <table border=\"1px\" cellpadding=\"5px\" cellspacing=\"-10px\">\n" + htmlTableThead + content +
+                "        </table>\n" +
+                "    </body>\n" +
+                "</html>";
+    }
+}

dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/Constants.java

@@ -75,6 +75,8 @@ public class Constants {
 
     public static final int NUMBER_1000 = 1000;
 
+    public static final String ALERT_TEMPLATE = "alert.template";
+
     public static final String SPRING_DATASOURCE_DRIVER_CLASS_NAME = "spring.datasource.driver-class-name";
 
     public static final String SPRING_DATASOURCE_URL = "spring.datasource.url";
@@ -115,8 +117,6 @@ public class Constants {
 
     public static final String DEVELOPMENT = "development";
 
-    public static final String CLASSPATH_MAIL_TEMPLATES_ALERT_MAIL_TEMPLATE_FTL = "classpath:mail_templates/alert_mail_template.ftl";
-
     public static final String TR = "<tr>";
 
     public static final String TD = "<td>";