Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 org.apache.hadoop.hdfs; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.CommonConfigurationKeysPublic; import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys; import static org.apache.hadoop.hdfs.client.HdfsClientConfigKeys.DeprecatedKeys; /** * Adds deprecated keys into the configuration. */ @InterfaceAudience.Private public class HdfsConfiguration extends Configuration { static { addDeprecatedKeys(); // adds the default resources Configuration.addDefaultResource("hdfs-default.xml"); Configuration.addDefaultResource("hdfs-site.xml"); } public HdfsConfiguration() { super(); } public HdfsConfiguration(boolean loadDefaults) { super(loadDefaults); } public HdfsConfiguration(Configuration conf) { super(conf); } /** * This method is here so that when invoked, HdfsConfiguration is class-loaded * if it hasn't already been previously loaded. Upon loading the class, the * static initializer block above will be executed to add the deprecated keys * and to add the default resources. It is safe for this method to be called * multiple times as the static initializer block will only get invoked once. * * This replaces the previously, dangerous practice of other classes calling * Configuration.addDefaultResource("hdfs-default.xml") directly without * loading this class first, thereby skipping the key deprecation. */ public static void init() { } private static void addDeprecatedKeys() { Configuration.addDeprecations(new DeprecationDelta[] { new DeprecationDelta("dfs.backup.address", DeprecatedKeys.DFS_NAMENODE_BACKUP_ADDRESS_KEY), new DeprecationDelta("dfs.backup.http.address", DeprecatedKeys.DFS_NAMENODE_BACKUP_HTTP_ADDRESS_KEY), new DeprecationDelta("dfs.balance.bandwidthPerSec", DeprecatedKeys.DFS_DATANODE_BALANCE_BANDWIDTHPERSEC_KEY), new DeprecationDelta("dfs.data.dir", DeprecatedKeys.DFS_DATANODE_DATA_DIR_KEY), new DeprecationDelta("dfs.http.address", HdfsClientConfigKeys.DFS_NAMENODE_HTTP_ADDRESS_KEY), new DeprecationDelta("dfs.https.address", HdfsClientConfigKeys.DFS_NAMENODE_HTTPS_ADDRESS_KEY), new DeprecationDelta("dfs.max.objects", DeprecatedKeys.DFS_NAMENODE_MAX_OBJECTS_KEY), new DeprecationDelta("dfs.name.dir", DeprecatedKeys.DFS_NAMENODE_NAME_DIR_KEY), new DeprecationDelta("dfs.name.dir.restore", DeprecatedKeys.DFS_NAMENODE_NAME_DIR_RESTORE_KEY), new DeprecationDelta("dfs.name.edits.dir", DeprecatedKeys.DFS_NAMENODE_EDITS_DIR_KEY), new DeprecationDelta("dfs.read.prefetch.size", HdfsClientConfigKeys.Read.PREFETCH_SIZE_KEY), new DeprecationDelta("dfs.safemode.extension", DeprecatedKeys.DFS_NAMENODE_SAFEMODE_EXTENSION_KEY), new DeprecationDelta("dfs.safemode.threshold.pct", DeprecatedKeys.DFS_NAMENODE_SAFEMODE_THRESHOLD_PCT_KEY), new DeprecationDelta("dfs.secondary.http.address", DeprecatedKeys.DFS_NAMENODE_SECONDARY_HTTP_ADDRESS_KEY), new DeprecationDelta("dfs.socket.timeout", HdfsClientConfigKeys.DFS_CLIENT_SOCKET_TIMEOUT_KEY), new DeprecationDelta("fs.checkpoint.dir", DeprecatedKeys.DFS_NAMENODE_CHECKPOINT_DIR_KEY), new DeprecationDelta("fs.checkpoint.edits.dir", DeprecatedKeys.DFS_NAMENODE_CHECKPOINT_EDITS_DIR_KEY), new DeprecationDelta("fs.checkpoint.period", DeprecatedKeys.DFS_NAMENODE_CHECKPOINT_PERIOD_KEY), new DeprecationDelta("heartbeat.recheck.interval", DeprecatedKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY), new DeprecationDelta("dfs.https.client.keystore.resource", DeprecatedKeys.DFS_CLIENT_HTTPS_KEYSTORE_RESOURCE_KEY), new DeprecationDelta("dfs.https.need.client.auth", DeprecatedKeys.DFS_CLIENT_HTTPS_NEED_AUTH_KEY), new DeprecationDelta("slave.host.name", DeprecatedKeys.DFS_DATANODE_HOST_NAME_KEY), new DeprecationDelta("session.id", DeprecatedKeys.DFS_METRICS_SESSION_ID_KEY), new DeprecationDelta("dfs.access.time.precision", DeprecatedKeys.DFS_NAMENODE_ACCESSTIME_PRECISION_KEY), new DeprecationDelta("dfs.replication.considerLoad", DeprecatedKeys.DFS_NAMENODE_REDUNDANCY_CONSIDERLOAD_KEY), new DeprecationDelta("dfs.namenode.replication.considerLoad", DeprecatedKeys.DFS_NAMENODE_REDUNDANCY_CONSIDERLOAD_KEY), new DeprecationDelta("dfs.namenode.replication.considerLoad.factor", DeprecatedKeys.DFS_NAMENODE_REDUNDANCY_CONSIDERLOAD_FACTOR), new DeprecationDelta("dfs.replication.interval", DeprecatedKeys.DFS_NAMENODE_REDUNDANCY_INTERVAL_SECONDS_KEY), new DeprecationDelta("dfs.namenode.replication.interval", DeprecatedKeys.DFS_NAMENODE_REDUNDANCY_INTERVAL_SECONDS_KEY), new DeprecationDelta("dfs.replication.min", DeprecatedKeys.DFS_NAMENODE_REPLICATION_MIN_KEY), new DeprecationDelta("dfs.replication.pending.timeout.sec", DeprecatedKeys.DFS_NAMENODE_RECONSTRUCTION_PENDING_TIMEOUT_SEC_KEY), new DeprecationDelta("dfs.namenode.replication.pending.timeout-sec", DeprecatedKeys.DFS_NAMENODE_RECONSTRUCTION_PENDING_TIMEOUT_SEC_KEY), new DeprecationDelta("dfs.max-repl-streams", DeprecatedKeys.DFS_NAMENODE_REPLICATION_MAX_STREAMS_KEY), new DeprecationDelta("dfs.permissions", DeprecatedKeys.DFS_PERMISSIONS_ENABLED_KEY), new DeprecationDelta("dfs.permissions.supergroup", DeprecatedKeys.DFS_PERMISSIONS_SUPERUSERGROUP_KEY), new DeprecationDelta("dfs.write.packet.size", HdfsClientConfigKeys.DFS_CLIENT_WRITE_PACKET_SIZE_KEY), new DeprecationDelta("dfs.block.size", HdfsClientConfigKeys.DFS_BLOCK_SIZE_KEY), new DeprecationDelta("dfs.datanode.max.xcievers", DeprecatedKeys.DFS_DATANODE_MAX_RECEIVER_THREADS_KEY), new DeprecationDelta("io.bytes.per.checksum", HdfsClientConfigKeys.DFS_BYTES_PER_CHECKSUM_KEY), new DeprecationDelta("dfs.federation.nameservices", HdfsClientConfigKeys.DFS_NAMESERVICES), new DeprecationDelta("dfs.federation.nameservice.id", DeprecatedKeys.DFS_NAMESERVICE_ID), new DeprecationDelta("dfs.encryption.key.provider.uri", CommonConfigurationKeysPublic.HADOOP_SECURITY_KEY_PROVIDER_PATH), }); } public static void main(String[] args) { init(); Configuration.dumpDeprecatedKeys(); } }