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.master.http.jersey;
019
020import java.util.function.Supplier;
021import javax.inject.Singleton;
022import org.apache.hadoop.hbase.http.jersey.SupplierFactoryAdapter;
023import org.apache.hadoop.hbase.master.HMaster;
024import org.apache.hadoop.hbase.master.MasterServices;
025import org.apache.yetus.audience.InterfaceAudience;
026
027import org.apache.hbase.thirdparty.javax.ws.rs.core.Feature;
028import org.apache.hbase.thirdparty.javax.ws.rs.core.FeatureContext;
029import org.apache.hbase.thirdparty.org.glassfish.hk2.utilities.binding.AbstractBinder;
030import org.apache.hbase.thirdparty.org.glassfish.hk2.utilities.binding.ServiceBindingBuilder;
031
032/**
033 * Implements a Singleton binding to the provided instance of {@link HMaster} for both
034 * {@link HMaster} and {@link MasterServices} injections.
035 */
036@InterfaceAudience.Private
037public class MasterFeature implements Feature {
038
039  private final Supplier<HMaster> supplier;
040
041  public MasterFeature(HMaster master) {
042    this.supplier = () -> master;
043  }
044
045  @Override
046  public boolean configure(FeatureContext context) {
047    context.register(new Binder());
048    return true;
049  }
050
051  /**
052   * Register this feature's provided functionality and defines their lifetime scopes.
053   */
054  private class Binder extends AbstractBinder {
055
056    @Override
057    protected void configure() {
058      bindFactory(supplier).to(HMaster.class).in(Singleton.class);
059      bindFactory(supplier).to(MasterServices.class).in(Singleton.class);
060    }
061
062    /**
063     * Helper method for smoothing over use of {@link SupplierFactoryAdapter}. Inspired by internal
064     * implementation details of jersey itself.
065     */
066    private <T> ServiceBindingBuilder<T> bindFactory(Supplier<T> supplier) {
067      return bindFactory(new SupplierFactoryAdapter<>(supplier));
068    }
069  }
070}