ZEPPELIN-45: Integrate Tajo with Zeppelin

conf/zeppelin-site.xml.template

@@ -60,7 +60,7 @@
 
 <property>
   <name>zeppelin.interpreters</name>
-  <value>org.apache.zeppelin.spark.SparkInterpreter,org.apache.zeppelin.spark.PySparkInterpreter,org.apache.zeppelin.spark.SparkSqlInterpreter,org.apache.zeppelin.spark.DepInterpreter,org.apache.zeppelin.markdown.Markdown,org.apache.zeppelin.angular.AngularInterpreter,org.apache.zeppelin.shell.ShellInterpreter,org.apache.zeppelin.hive.HiveInterpreter</value>
+  <value>org.apache.zeppelin.spark.SparkInterpreter,org.apache.zeppelin.spark.PySparkInterpreter,org.apache.zeppelin.spark.SparkSqlInterpreter,org.apache.zeppelin.spark.DepInterpreter,org.apache.zeppelin.markdown.Markdown,org.apache.zeppelin.angular.AngularInterpreter,org.apache.zeppelin.shell.ShellInterpreter,org.apache.zeppelin.hive.HiveInterpreter,org.apache.zeppelin.tajo.TajoInterpreter</value>
   <description>Comma separated interpreter configurations. First interpreter become a default</description>
 </property>
 

pom.xml

@@ -91,6 +91,7 @@
     <module>angular</module>
     <module>shell</module>
     <module>hive</module>
+    <module>tajo</module>
     <module>zeppelin-web</module>
     <module>zeppelin-server</module>
     <module>zeppelin-distribution</module>
@@ -113,6 +114,7 @@
     <hbase.version>0.94.6</hbase.version>
     <zookeeper.version>3.4.5</zookeeper.version>
     <hive.version>0.12.0</hive.version>
+    <tajo.version>0.10.0</tajo.version>
     <derby.version>10.4.2.0</derby.version>
     <parquet.version>1.4.3</parquet.version>
     <jblas.version>1.2.3</jblas.version>

tajo/pom.xml

@@ -0,0 +1,138 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ 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.
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <artifactId>zeppelin</artifactId>
+    <groupId>org.apache.zeppelin</groupId>
+    <version>0.5.0-SNAPSHOT</version>
+  </parent>
+
+  <groupId>org.apache.zeppelin</groupId>
+  <artifactId>zeppelin-tajo</artifactId>
+  <packaging>jar</packaging>
+  <version>0.5.0-SNAPSHOT</version>
+  <name>Zeppelin: Tajo interpreter</name>
+  <url>http://www.apache.org</url>
+
+  <properties>
+    <protobuf.version>2.5.0</protobuf.version>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.zeppelin</groupId>
+      <artifactId>zeppelin-interpreter</artifactId>
+      <version>${project.version}</version>
+      <scope>provided</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-log4j12</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>org.apache.tajo</groupId>
+      <artifactId>tajo-jdbc</artifactId>
+      <version>${tajo.version}</version>
+    </dependency>
+
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-deploy-plugin</artifactId>
+        <version>2.7</version>
+        <configuration>
+          <skip>true</skip>
+        </configuration>
+      </plugin>
+
+      <plugin>
+        <artifactId>maven-enforcer-plugin</artifactId>
+        <version>1.3.1</version>
+        <executions>
+          <execution>
+            <id>enforce</id>
+            <phase>none</phase>
+          </execution>
+        </executions>
+      </plugin>
+
+      <plugin>
+        <artifactId>maven-dependency-plugin</artifactId>
+        <version>2.8</version>
+        <executions>
+          <execution>
+            <id>copy-dependencies</id>
+            <phase>package</phase>
+            <goals>
+              <goal>copy-dependencies</goal>
+            </goals>
+            <configuration>
+              <outputDirectory>${project.build.directory}/../../interpreter/tajo</outputDirectory>
+              <overWriteReleases>false</overWriteReleases>
+              <overWriteSnapshots>false</overWriteSnapshots>
+              <overWriteIfNewer>true</overWriteIfNewer>
+              <includeScope>runtime</includeScope>
+            </configuration>
+          </execution>
+          <execution>
+            <id>copy-artifact</id>
+            <phase>package</phase>
+            <goals>
+              <goal>copy</goal>
+            </goals>
+            <configuration>
+              <outputDirectory>${project.build.directory}/../../interpreter/tajo</outputDirectory>
+              <overWriteReleases>false</overWriteReleases>
+              <overWriteSnapshots>false</overWriteSnapshots>
+              <overWriteIfNewer>true</overWriteIfNewer>
+              <includeScope>runtime</includeScope>
+              <artifactItems>
+                <artifactItem>
+                  <groupId>${project.groupId}</groupId>
+                  <artifactId>${project.artifactId}</artifactId>
+                  <version>${project.version}</version>
+                  <type>${project.packaging}</type>
+                </artifactItem>
+              </artifactItems>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+
+
+</project>

tajo/src/main/java/org/apache/zeppelin/tajo/TajoInterpreter.java

@@ -0,0 +1,195 @@
+/**
+ * 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.zeppelin.tajo;
+
+import java.sql.*;
+import java.util.List;
+import java.util.Properties;
+
+import org.apache.zeppelin.interpreter.*;
+import org.apache.commons.lang.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.apache.zeppelin.interpreter.InterpreterResult.Code;
+import org.apache.zeppelin.scheduler.Scheduler;
+import org.apache.zeppelin.scheduler.SchedulerFactory;
+
+/**
+ * Tajo interpreter for Zeppelin.
+ */
+public class TajoInterpreter extends Interpreter {
+  private Logger logger = LoggerFactory.getLogger(TajoInterpreter.class);
+
+  private Connection connection;
+  private Statement statement;
+  private Exception exceptionOnConnect;
+
+  public static final String TAJO_JDBC_URI = "tajo.jdbc.uri";
+  public static final String TAJO_DRIVER_NAME = "org.apache.tajo.jdbc.TajoDriver";
+
+  static {
+    Interpreter.register(
+      "tajo",
+      "tajo",
+      TajoInterpreter.class.getName(),
+      new InterpreterPropertyBuilder()
+        .add(TAJO_JDBC_URI, "jdbc:tajo://localhost:26002/default", "The URL for TajoServer.")
+        .build());
+  }
+
+  public TajoInterpreter(Properties property) {
+    super(property);
+  }
+
+  public Connection getJdbcConnection() throws SQLException {
+    return DriverManager.getConnection(getProperty(TAJO_JDBC_URI));
+  }
+
+  @Override
+  public void open() {
+    logger.info("Jdbc open connection called!");
+    try {
+      Class.forName(TAJO_DRIVER_NAME);
+    } catch (ClassNotFoundException e) {
+      logger.error("Can not open connection", e);
+      exceptionOnConnect = e;
+      return;
+    }
+    try {
+      connection = getJdbcConnection();
+      exceptionOnConnect = null;
+      logger.info("Successfully created connection");
+    }
+    catch (SQLException e) {
+      logger.error("Cannot open connection", e);
+      exceptionOnConnect = e;
+    }
+  }
+
+  @Override
+  public void close() {
+    try {
+      if (connection != null) {
+        connection.close();
+      }
+    }
+    catch (SQLException e) {
+      logger.error("Cannot close connection", e);
+    }
+    finally {
+      connection = null;
+      exceptionOnConnect = null;
+    }
+  }
+
+  private InterpreterResult executeSql(String sql) {
+    try {
+      if (exceptionOnConnect != null) {
+        return new InterpreterResult(Code.ERROR, exceptionOnConnect.getMessage());
+      }
+      statement = connection.createStatement();
+      StringBuilder msg = null;
+      if (StringUtils.containsIgnoreCase(sql, "EXPLAIN ")) {
+        //return the explain as text, make this visual explain later
+        msg = new StringBuilder();
+      }
+      else {
+        msg = new StringBuilder("%table ");
+      }
+
+      ResultSet res = statement.executeQuery(sql);
+      try {
+        ResultSetMetaData md = res.getMetaData();
+        for (int i = 1; i < md.getColumnCount() + 1; i++) {
+          if (i == 1) {
+            msg.append(md.getColumnName(i));
+          } else {
+            msg.append("\t" + md.getColumnName(i));
+          }
+        }
+        msg.append("\n");
+        while (res.next()) {
+          for (int i = 1; i < md.getColumnCount() + 1; i++) {
+            msg.append(res.getString(i) + "\t");
+          }
+          msg.append("\n");
+        }
+      }
+      finally {
+        try {
+          res.close();
+          statement.close();
+        }
+        finally {
+          statement = null;
+        }
+      }
+
+      InterpreterResult interpreterResult = new InterpreterResult(Code.SUCCESS, msg.toString());
+      return interpreterResult;
+    }
+    catch (SQLException ex) {
+      logger.error("Can not run " + sql, ex);
+      return new InterpreterResult(Code.ERROR, ex.getMessage());
+    }
+  }
+
+  @Override
+  public InterpreterResult interpret(String cmd, InterpreterContext contextInterpreter) {
+    logger.info("Run SQL command '" + cmd + "'");
+    return executeSql(cmd);
+  }
+
+  @Override
+  public void cancel(InterpreterContext context) {
+    // Currently, Tajo doesn't provide JDBC cancel method. It will be implemented in
+    // Tajo 0.11.0 version. You can find related issue progress at TAJO-751.
+//    if (statement != null) {
+//      try {
+//        statement.cancel();
+//      }
+//      catch (SQLException ex) {
+//      }
+//      finally {
+//        statement = null;
+//      }
+//    }
+  }
+
+  @Override
+  public FormType getFormType() {
+    return FormType.SIMPLE;
+  }
+
+  @Override
+  public int getProgress(InterpreterContext context) {
+    return 0;
+  }
+
+  @Override
+  public Scheduler getScheduler() {
+    return SchedulerFactory.singleton().createOrGetFIFOScheduler(
+      TajoInterpreter.class.getName() + this.hashCode());
+  }
+
+  @Override
+  public List<String> completion(String buf, int cursor) {
+    return null;
+  }
+}