#38 - Add Cockroach DB detection

Refactor extract method ensuring we close resources

pom.xml

@@ -67,6 +67,13 @@
       <scope>test</scope>
     </dependency>
 
+    <dependency>
+      <groupId>ch.qos.logback</groupId>
+      <artifactId>logback-classic</artifactId>
+      <version>1.2.3</version>
+      <scope>test</scope>
+    </dependency>
+
   </dependencies>
 
   <build>

src/main/java/io/ebean/migration/DbNameUtil.java

@@ -1,13 +1,21 @@
 package io.ebean.migration;
 
+import io.ebean.migration.util.JdbcClose;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
 import java.sql.SQLException;
 
 /**
  * Derive well known database platform names from JDBC MetaData.
  */
 class DbNameUtil implements DbPlatformNames {
 
+  private static final Logger log = LoggerFactory.getLogger(DbNameUtil.class);
+
   /**
    * Normalise the database product/platform name.
    *
@@ -18,23 +26,7 @@ static String normalise(Connection connection) {
     try {
       final String productName = connection.getMetaData().getDatabaseProductName().toLowerCase();
       if (productName.contains(POSTGRES)) {
-        // PostgreSQL driver use a non-trustable hardcoded product name.
-        // The following block try to retrieve DBMS version to determine
-        // if used DBMS is PostgreSQL or Cockroach.
-        try {
-          final String productVersion = connection
-                  .prepareStatement("SELECT version() AS \"version\"")
-                  .executeQuery()
-                  .getString("version")
-                  .toLowerCase();
-          if (productVersion.contains("cockroach")) {
-            return COCKROACH;
-          }
-        } catch (final java.sql.SQLException ignore) {
-        }
-
-        // Real PostgreSQL DB
-        return POSTGRES;
+        return readPostgres(connection);
       } else if (productName.contains(MYSQL)) {
         return MYSQL;
       } else if (productName.contains(ORACLE)) {
@@ -58,4 +50,31 @@ static String normalise(Connection connection) {
       return "";
     }
   }
+
+  private static String readPostgres(Connection connection) {
+    // PostgreSQL driver use a non-trustable hardcoded product name.
+    // The following block try to retrieve DBMS version to determine
+    // if used DBMS is PostgreSQL or Cockroach.
+    PreparedStatement statement = null;
+    ResultSet resultSet = null;
+    try {
+      statement = connection.prepareStatement("SELECT version() AS \"version\"");
+      resultSet = statement.executeQuery();
+      if (resultSet.next()) {
+        String productVersion = resultSet.getString("version").toLowerCase();
+        if (productVersion.contains("cockroach")) {
+          return COCKROACH;
+        }
+      }
+    } catch (SQLException e) {
+      log.warn("Error running detection query on Postgres", e);
+
+    } finally {
+      JdbcClose.close(resultSet);
+      JdbcClose.close(statement);
+    }
+
+    // Real PostgreSQL DB
+    return POSTGRES;
+  }
 }

src/test/java/io/ebean/migration/DbNameUtilTest.java

@@ -0,0 +1,62 @@
+package io.ebean.migration;
+
+import jdk.nashorn.internal.ir.annotations.Ignore;
+import org.testng.annotations.Test;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class DbNameUtilTest {
+
+  /**
+   * Run manually against Postgres database.
+   */
+  @Ignore
+  @Test
+  public void normalise_when_realPostgres() throws SQLException {
+
+    MigrationConfig config = createConfig();
+    // assumes DB unit exists on our local postgres database
+    config.setDbUrl("jdbc:postgresql://127.0.0.1:5432/unit");
+
+    try (Connection connection = config.createConnection()) {
+      String platformName = DbNameUtil.normalise(connection);
+
+      assertThat(platformName).isEqualTo("postgres");
+    } catch (SQLException e) {
+      throw e;
+    }
+  }
+
+  /**
+   * Run manually against cockroach database.
+   */
+  @Ignore
+  @Test
+  public void normalise_when_cockroach() throws SQLException {
+
+    MigrationConfig config = createConfig();
+    // assumes DB unit exists on our local cockroach database
+    config.setDbUrl("jdbc:postgresql://127.0.0.1:26257/unit");
+
+    try (Connection connection = config.createConnection()) {
+      String platformName = DbNameUtil.normalise(connection);
+      assertThat(platformName).isEqualTo("cockroach");
+    } catch (SQLException e) {
+      throw e;
+    }
+  }
+
+  /**
+   * Assumes a DB user unit exists on the databases.
+   */
+  private MigrationConfig createConfig() {
+    MigrationConfig config = new MigrationConfig();
+    config.setDbUsername("unit");
+    config.setDbPassword("unit");
+    config.setDbDriver("org.postgresql.Driver");
+    return config;
+  }
+}