hbase-server/src/test/java/org/apache/hadoop/hbase/MiniClusterRule.java

   1 /*
   2  * Licensed to the Apache Software Foundation (ASF) under one
   3  * or more contributor license agreements.  See the NOTICE file
   4  * distributed with this work for additional information
   5  * regarding copyright ownership.  The ASF licenses this file
   6  * to you under the Apache License, Version 2.0 (the
   7  * "License"); you may not use this file except in compliance
   8  * with the License.  You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  */
  18 package org.apache.hadoop.hbase;
  19
  20 import java.io.IOException;
  21 import java.util.concurrent.CompletableFuture;
  22 import org.apache.hadoop.hbase.client.AsyncConnection;
  23 import org.apache.hadoop.hbase.client.ConnectionFactory;
  24 import org.junit.ClassRule;
  25 import org.junit.Rule;
  26 import org.junit.rules.ExternalResource;
  27 import org.junit.rules.TestRule;
  28
  29 /**
  30  * A {@link TestRule} that manages an instance of the {@link MiniHBaseCluster}. Can be used in
  31  * either the {@link Rule} or {@link ClassRule} positions. Built on top of an instance of
  32  * {@link HBaseTestingUtility}, so be weary of intermixing direct use of that class with this Rule.
  33  * </p>
  34  * Use in combination with {@link ConnectionRule}, for example:
  35  *
  36  * <pre>{@code
  37  *   public class TestMyClass {
  38  *     @ClassRule
  39  *     public static final MiniClusterRule miniClusterRule = new MiniClusterRule();
  40  *
  41  *     @Rule
  42  *     public final ConnectionRule connectionRule =
  43  *       new ConnectionRule(miniClusterRule::createConnection);
  44  *   }
  45  * }</pre>
  46  */
  47 public class MiniClusterRule extends ExternalResource {
  48   private final HBaseTestingUtility testingUtility;
  49   private final StartMiniClusterOption miniClusterOptions;
  50
  51   private MiniHBaseCluster miniCluster;
  52
  53   /**
  54    * Create an instance over the default options provided by {@link StartMiniClusterOption}.
  55    */
  56   public MiniClusterRule() {
  57     this(StartMiniClusterOption.builder().build());
  58   }
  59
  60   /**
  61    * Create an instance using the provided {@link StartMiniClusterOption}.
  62    */
  63   public MiniClusterRule(final StartMiniClusterOption miniClusterOptions) {
  64     this.testingUtility = new HBaseTestingUtility();
  65     this.miniClusterOptions = miniClusterOptions;
  66   }
  67
  68   /**
  69    * @return the underlying instance of {@link HBaseTestingUtility}
  70    */
  71   public HBaseTestingUtility getTestingUtility() {
  72     return testingUtility;
  73   }
  74
  75   /**
  76    * Create a {@link AsyncConnection} to the managed {@link MiniHBaseCluster}. It's up to the caller
  77    * to {@link AsyncConnection#close() close()} the connection when finished.
  78    */
  79   public CompletableFuture<AsyncConnection> createConnection() {
  80     if (miniCluster == null) {
  81       throw new IllegalStateException("test cluster not initialized");
  82     }
  83     return ConnectionFactory.createAsyncConnection(miniCluster.getConf());
  84   }
  85
  86   @Override
  87   protected void before() throws Throwable {
  88     miniCluster = testingUtility.startMiniCluster(miniClusterOptions);
  89   }
  90
  91   @Override
  92   protected void after() {
  93     try {
  94       testingUtility.shutdownMiniCluster();
  95     } catch (IOException e) {
  96       throw new RuntimeException(e);
  97     }
  98   }
  99 }