001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase;
019
020import java.io.IOException;
021import java.util.concurrent.CompletableFuture;
022import java.util.function.Supplier;
023import org.apache.hadoop.hbase.client.AsyncConnection;
024import org.junit.ClassRule;
025import org.junit.Rule;
026import org.junit.rules.ExternalResource;
027
028/**
029 * A {@link Rule} that manages the lifecycle of an instance of {@link AsyncConnection}. Can be used
030 * in either the {@link Rule} or {@link ClassRule} positions.
031 * </p>
032 * Use in combination with {@link MiniClusterRule}, for example:
033 *
034 * <pre>{@code
035 *   public class TestMyClass {
036 *     private static final MiniClusterRule miniClusterRule = MiniClusterRule.newBuilder().build();
037 *     private static final ConnectionRule connectionRule =
038 *       new ConnectionRule(miniClusterRule::createConnection);
039 *
040 *     @ClassRule
041 *     public static final TestRule rule = RuleChain
042 *       .outerRule(miniClusterRule)
043 *       .around(connectionRule);
044 *   }
045 * }</pre>
046 */
047public class ConnectionRule extends ExternalResource {
048
049  private final Supplier<CompletableFuture<AsyncConnection>> connectionSupplier;
050  private AsyncConnection connection;
051
052  public ConnectionRule(final Supplier<CompletableFuture<AsyncConnection>> connectionSupplier) {
053    this.connectionSupplier = connectionSupplier;
054  }
055
056  public AsyncConnection getConnection() {
057    return connection;
058  }
059
060  @Override
061  protected void before() throws Throwable {
062    this.connection = connectionSupplier.get().join();
063  }
064
065  @Override
066  protected void after() {
067    if (this.connection != null) {
068      try {
069        connection.close();
070      } catch (IOException e) {
071        throw new RuntimeException(e);
072      }
073    }
074  }
075}