Java tutorial
/* * Copyright 2014 NAVER Corp. * * 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.jxt.web.dao.hbase; import com.jxt.web.dao.AgentInfoDao; import com.jxt.web.mapper.AgentInfoMapper; import com.jxt.web.vo.AgentInfo; import com.navercorp.pinpoint.common.hbase.HBaseTables; import com.navercorp.pinpoint.common.hbase.HbaseOperations2; import com.navercorp.pinpoint.common.hbase.ResultsExtractor; import com.navercorp.pinpoint.common.util.RowKeyUtils; import com.navercorp.pinpoint.common.util.TimeUtils; import org.apache.commons.collections.CollectionUtils; import org.apache.hadoop.hbase.client.*; import org.apache.hadoop.hbase.util.Bytes; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Repository; import java.util.ArrayList; import java.util.Collections; import java.util.List; /** * @author emeroad * @author HyunGil Jeong */ @Repository public class HbaseAgentInfoDao implements AgentInfoDao { private static final int SCANNER_CACHING = 1; @Autowired private HbaseOperations2 hbaseOperations2; @Autowired private AgentInfoMapper agentInfoMapper; /** * Returns the very first information of the agent * * @param agentId */ @Override public AgentInfo getInitialAgentInfo(final String agentId) { if (agentId == null) { throw new NullPointerException("agentId must not be null"); } Scan scan = createScanForInitialAgentInfo(agentId); return this.hbaseOperations2.find(HBaseTables.AGENTINFO, scan, new AgentInfoResultsExtractor()); } @Override public List<AgentInfo> getInitialAgentInfos(List<String> agentIds) { if (agentIds == null || agentIds.isEmpty()) { return Collections.emptyList(); } List<Scan> scans = new ArrayList<>(agentIds.size()); for (String agentId : agentIds) { scans.add(createScanForInitialAgentInfo(agentId)); } return this.hbaseOperations2.find(HBaseTables.AGENTINFO, scans, new AgentInfoResultsExtractor()); } private Scan createScanForInitialAgentInfo(String agentId) { Scan scan = new Scan(); byte[] agentIdBytes = Bytes.toBytes(agentId); byte[] reverseStartKey = RowKeyUtils.concatFixedByteAndLong(agentIdBytes, HBaseTables.AGENT_NAME_MAX_LEN, Long.MAX_VALUE); scan.setStartRow(reverseStartKey); scan.setReversed(true); scan.setMaxVersions(1); scan.setCaching(SCANNER_CACHING); return scan; } /** * Returns the information of the agent with its start time closest to the given timestamp * * @param agentId * @param timestamp * @return */ @Override public AgentInfo getAgentInfo(final String agentId, final long timestamp) { if (agentId == null) { throw new NullPointerException("agentId must not be null"); } Scan scan = createScan(agentId, timestamp); return this.hbaseOperations2.find(HBaseTables.AGENTINFO, scan, new AgentInfoResultsExtractor()); } @Override public List<AgentInfo> getAgentInfos(List<String> agentIds, long timestamp) { if (CollectionUtils.isEmpty(agentIds)) { return Collections.emptyList(); } List<Scan> scans = new ArrayList<>(agentIds.size()); for (String agentId : agentIds) { scans.add(createScan(agentId, timestamp)); } return this.hbaseOperations2.findParallel(HBaseTables.AGENTINFO, scans, new AgentInfoResultsExtractor()); } private Scan createScan(String agentId, long currentTime) { Scan scan = new Scan(); byte[] agentIdBytes = Bytes.toBytes(agentId); long startTime = TimeUtils.reverseTimeMillis(currentTime); byte[] startKeyBytes = RowKeyUtils.concatFixedByteAndLong(agentIdBytes, HBaseTables.AGENT_NAME_MAX_LEN, startTime); byte[] endKeyBytes = RowKeyUtils.concatFixedByteAndLong(agentIdBytes, HBaseTables.AGENT_NAME_MAX_LEN, Long.MAX_VALUE); scan.setStartRow(startKeyBytes); scan.setStopRow(endKeyBytes); scan.addFamily(HBaseTables.AGENTINFO_CF_INFO); scan.setMaxVersions(1); scan.setCaching(SCANNER_CACHING); return scan; } private class AgentInfoResultsExtractor implements ResultsExtractor<AgentInfo> { @Override public AgentInfo extractData(ResultScanner results) throws Exception { int found = 0; for (Result result : results) { return agentInfoMapper.mapRow(result, found++); } return null; } } }