[#13] Add name to ConnectorCreator, use it when instantiating

the connector to choose one over the others

Author: agilelab-tmnd1991

README.md

@@ -200,13 +200,11 @@ classpath)
 
 Example of configuration for the `HBaseConnector`:
 ```
-hbase {
-  "isSecure": false,
-  "namespace": "DARWIN",
-  "table": "REPOSITORY",
-  "coreSite": "/etc/hadoop/conf/core-site.xml",
-  "hbaseSite": "/etc/hadoop/conf/hbase-site.xml",
-}
+"isSecure": false,
+"namespace": "DARWIN",
+"table": "REPOSITORY",
+"coreSite": "/etc/hadoop/conf/core-site.xml",
+"hbaseSite": "/etc/hadoop/conf/hbase-site.xml",
 ```
 ### HBase Connector dependencies
 Darwin HBase Connector does not provide HBase dependencies in a transitive manner since that would lead to hard to 
@@ -225,11 +223,9 @@ The configuration keys managed by the `PostgresConnector` are:
 
 Example of configuration for the `PostgresConnector`:
 ```
-postgres {
-  "host": "localhost:5432"
-  "db": "srdb"
-  "username": "postgres"
-  "password": "srpsql"
-  "table": "schema_registry"
-}
+"host": "localhost:5432"
+"db": "srdb"
+"username": "postgres"
+"password": "srpsql"
+"table": "schema_registry"
 ```

common/src/main/scala/it/agilelab/darwin/common/ConnectorCreator.scala

@@ -7,6 +7,11 @@ import com.typesafe.config.Config
   */
 trait ConnectorCreator {
 
+  /**
+    * @return the name of the Connector
+    */
+  def name(): String
+
   /**
     * This method should be overridden in each connector module returning its implementation.
     *

common/src/main/scala/it/agilelab/darwin/common/ConnectorFactory.scala

@@ -1,15 +1,17 @@
 package it.agilelab.darwin.common
 
 import java.util.ServiceLoader
+
+import com.typesafe.config.Config
+import it.agilelab.darwin.manager.util.ConfigurationKeys
+
 import scala.collection.JavaConverters._
 
 /**
   * Used to obtain the correct implementation of [[Connector]] found on the classpath using the [[ConnectorCreator]]
   */
 object ConnectorFactory extends Logging {
 
-  private val DEFAULT_PROVIDER: String = "TEST" //TODO set a default implementation
-
   /**
     * Retrieves all the registered [[ConnectorCreator]] in the classpath.
     *
@@ -21,13 +23,29 @@ object ConnectorFactory extends Logging {
     creators
   }
 
-  def creator(): ConnectorCreator = creator(DEFAULT_PROVIDER)
+  /**
+    * @return the first ConnectorCreator, use ONLY if you are sure that just one is available in the classpath
+    */
+  def creator(): Option[ConnectorCreator] = creators().headOption
+
 
-  def creator(name: String): ConnectorCreator = {
-    creators().find(_.getClass.getName == name) match {
-      case Some(c) => c
-      case _ => throw new ClassNotFoundException("Creator " + name + " not found")
+  /**
+    * @return the ConnectorCreator identified by the name given as input
+    */
+  def creator(name: String): Option[ConnectorCreator] = {
+    creators().find(_.name == name)
+  }
+
+  /**
+    * @return the ConnectorCreator identified by the name given as input
+    */
+  def creator(conf: Config): Option[ConnectorCreator] = {
+    if (conf.hasPath(ConfigurationKeys.CONNECTOR)) {
+      creator(conf.getString(ConfigurationKeys.CONNECTOR))
+    } else {
+      creator()
     }
   }
 
+
 }

core/src/main/scala/it/agilelab/darwin/manager/util/ByteArrayUtils.scala renamed to common/src/main/scala/it/agilelab/darwin/manager/util/ByteArrayUtils.scala

@@ -4,4 +4,6 @@ object ConfigurationKeys {
 
   val CREATE_TABLE = "createTable"
 
+  val CONNECTOR = "connector"
+
 }

core/src/main/scala/it/agilelab/darwin/manager/util/ConfigUtil.scala renamed to common/src/main/scala/it/agilelab/darwin/manager/util/ConfigUtil.scala

@@ -22,7 +22,7 @@ trait AvroSchemaManager extends Logging {
   protected def config: Config
 
   protected[darwin] lazy val connector: Connector = {
-    val cnt = ConnectorFactory.creators().headOption.map(_.create(config))
+    val cnt = ConnectorFactory.creator(config).map(_.create(config))
       .getOrElse(throw new ConnectorNotFoundException(config))
 
     if (config.getBoolean(ConfigurationKeys.CREATE_TABLE)) {

core/src/main/scala/it/agilelab/darwin/manager/util/ConfigurationKeys.scala renamed to common/src/main/scala/it/agilelab/darwin/manager/util/ConfigurationKeys.scala

@@ -10,4 +10,9 @@ class HBaseConnectorCreator extends ConnectorCreator with Logging {
     log.debug("HBase connector created")
     connector
   }
+
+  /**
+    * @return the name of the Connector
+    */
+  override def name(): String = "hbase"
 }

core/src/main/scala/it/agilelab/darwin/manager/AvroSchemaManager.scala

@@ -5,4 +5,9 @@ import it.agilelab.darwin.common.{Connector, ConnectorCreator}
 
 class IgniteConnectorCreator extends ConnectorCreator {
   override def create(config: Config): Connector = new IgniteConnector(config)
+
+  /**
+    * @return the name of the Connector
+    */
+  override def name(): String = "ignite"
 }

hbase/src/main/scala/it/agilelab/darwin/connector/hbase/HBaseConnectorCreator.scala

@@ -5,4 +5,9 @@ import it.agilelab.darwin.common.{Connector, ConnectorCreator}
 
 class MockConnectorCreator extends ConnectorCreator {
   override def create(config: Config): Connector = new MockConnector(config)
+
+  /**
+    * @return the name of the Connector
+    */
+  override def name(): String = "mock"
 }