[b/382467945] Move parts of JdbcHandle logic to a util class (#679)

Author: misolt

dumper/app/src/main/java/com/google/edwmigration/dumper/application/dumper/handle/HandleUtil.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2022-2024 Google LLC
+ * Copyright 2013-2021 CompilerWorks
+ *
+ * Licensed 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 com.google.edwmigration.dumper.application.dumper.handle;
+
+import com.zaxxer.hikari.HikariConfig;
+import java.sql.Connection;
+import java.sql.SQLException;
+import javax.annotation.ParametersAreNonnullByDefault;
+import javax.sql.DataSource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.jdbc.core.JdbcTemplate;
+
+@ParametersAreNonnullByDefault
+public class HandleUtil {
+
+  private static final Logger LOG = LoggerFactory.getLogger(HandleUtil.class);
+
+  public static JdbcTemplate createJdbcTemplate(DataSource dataSource) {
+    JdbcTemplate template = new JdbcTemplate(dataSource);
+    template.setFetchSize(1024);
+    return template;
+  }
+
+  static void verifyJdbcConnection(DataSource dataSource) throws SQLException {
+    LOG.debug("Testing connection to database using {}...", dataSource);
+    try (Connection connection = dataSource.getConnection()) {
+      LOG.debug("Obtained connection is: {}");
+      if (connection == null) {
+        LOG.error("DataSource failed to provide a connection (usually bad/mismatched JDBC URI).");
+        // This used to be thrown by Preconditions and was kept for compatibility.
+        // TODO: Replace with a better error.
+        throw new NullPointerException();
+      } else {
+        LOG.debug("Connection test succeeded");
+      }
+    }
+  }
+
+  public static HikariConfig createHikariConfig(DataSource dataSource, int threadPoolSize) {
+    HikariConfig config = new HikariConfig();
+    // providing "0" sets it to Integer.MAX_VALUE
+    config.setConnectionTimeout(0);
+    config.setDataSource(dataSource);
+    // Question: If a connection goes out to lunch, causing getConnection() to block for a thread,
+    // can that deadlock the dumper?
+    config.setMaximumPoolSize(threadPoolSize);
+    config.setMinimumIdle(0);
+    return config;
+  }
+
+  private HandleUtil() {}
+}

dumper/app/src/main/java/com/google/edwmigration/dumper/application/dumper/handle/JdbcHandle.java

@@ -16,11 +16,9 @@
  */
 package com.google.edwmigration.dumper.application.dumper.handle;
 
-import com.google.common.base.Preconditions;
 import com.zaxxer.hikari.HikariConfig;
 import com.zaxxer.hikari.HikariDataSource;
 import java.io.IOException;
-import java.sql.Connection;
 import java.sql.SQLException;
 import javax.annotation.Nonnull;
 import javax.sql.DataSource;
@@ -40,30 +38,15 @@ public class JdbcHandle extends AbstractHandle {
   @Nonnull
   public static JdbcHandle newPooledJdbcHandle(@Nonnull DataSource dataSource, int threadPoolSize)
       throws SQLException {
-    HikariConfig config = new HikariConfig();
-    config.setDataSource(dataSource);
-    config.setMinimumIdle(0);
-    // Question: If a connection goes out to lunch, causing getConnection() to block for a thread,
-    // can that deadlock the dumper?
-    config.setMaximumPoolSize(threadPoolSize);
-    config.setConnectionTimeout(0); // 0 equals Integer.MAX_VALUE
+    HikariConfig config = HandleUtil.createHikariConfig(dataSource, threadPoolSize);
     return new JdbcHandle(new HikariDataSource(config));
   }
 
   private final JdbcTemplate jdbcTemplate;
 
   public JdbcHandle(@Nonnull DataSource dataSource) throws SQLException {
-    Preconditions.checkNotNull(dataSource, "DataSource was null.");
-    LOG.debug("Testing connection to database using " + dataSource + "...");
-    try (Connection connection = dataSource.getConnection()) {
-      Preconditions.checkNotNull(
-          connection,
-          "DataSource did not return a connection (Usually bad/mismatched JDBC URI?): %s",
-          dataSource);
-      LOG.debug("Connection test succeeded; obtained " + connection);
-    }
-    this.jdbcTemplate = new JdbcTemplate(dataSource);
-    jdbcTemplate.setFetchSize(1024);
+    HandleUtil.verifyJdbcConnection(dataSource);
+    this.jdbcTemplate = HandleUtil.createJdbcTemplate(dataSource);
   }
 
   @Nonnull

dumper/app/src/test/java/com/google/edwmigration/dumper/application/dumper/handle/HandleUtilTest.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2022-2024 Google LLC
+ * Copyright 2013-2021 CompilerWorks
+ *
+ * Licensed 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 com.google.edwmigration.dumper.application.dumper.handle;
+
+import static com.google.edwmigration.dumper.application.dumper.handle.HandleUtil.createHikariConfig;
+import static com.google.edwmigration.dumper.application.dumper.handle.HandleUtil.createJdbcTemplate;
+import static com.google.edwmigration.dumper.application.dumper.handle.HandleUtil.verifyJdbcConnection;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThrows;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import com.zaxxer.hikari.HikariConfig;
+import java.sql.SQLException;
+import javax.sql.DataSource;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.junit.MockitoJUnitRunner;
+import org.springframework.jdbc.core.JdbcTemplate;
+
+@RunWith(MockitoJUnitRunner.class)
+public class HandleUtilTest {
+
+  @Test
+  public void templateFromDataSource_success_fetchSizeMatches() {
+    DataSource dataSource = mock(DataSource.class);
+
+    JdbcTemplate template = createJdbcTemplate(dataSource);
+
+    assertEquals(1024, template.getFetchSize());
+  }
+
+  @Test
+  public void verifyJdbcConnection_nullConnection_exceptionThrown() throws SQLException {
+    DataSource dataSource = mock(DataSource.class);
+    when(dataSource.getConnection()).thenReturn(null);
+
+    assertThrows(NullPointerException.class, () -> verifyJdbcConnection(dataSource));
+  }
+
+  @Test
+  public void withPoolConfig_success_poolSizeMatches() {
+    DataSource dataSource = mock(DataSource.class);
+
+    HikariConfig config = createHikariConfig(dataSource, 2);
+
+    assertEquals(2, config.getMaximumPoolSize());
+  }
+
+  @Test
+  public void withPoolConfig_success_timeoutEqualsIntMax() {
+    DataSource dataSource = mock(DataSource.class);
+
+    HikariConfig config = createHikariConfig(dataSource, 1);
+
+    assertEquals(Integer.MAX_VALUE, config.getConnectionTimeout());
+  }
+}