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.rest; 019 020import java.io.IOException; 021import java.util.Iterator; 022import java.util.NoSuchElementException; 023import org.apache.hadoop.hbase.Cell; 024import org.apache.hadoop.hbase.CellUtil; 025import org.apache.hadoop.hbase.DoNotRetryIOException; 026import org.apache.hadoop.hbase.client.Get; 027import org.apache.hadoop.hbase.client.Result; 028import org.apache.hadoop.hbase.client.Table; 029import org.apache.hadoop.hbase.filter.Filter; 030import org.apache.hadoop.hbase.security.AccessDeniedException; 031import org.apache.hadoop.util.StringUtils; 032import org.apache.yetus.audience.InterfaceAudience; 033import org.slf4j.Logger; 034import org.slf4j.LoggerFactory; 035 036@InterfaceAudience.Private 037public class RowResultGenerator extends ResultGenerator { 038 private static final Logger LOG = LoggerFactory.getLogger(RowResultGenerator.class); 039 040 private Iterator<Cell> valuesI; 041 private Cell cache; 042 043 public RowResultGenerator(final String tableName, final RowSpec rowspec, final Filter filter, 044 final boolean cacheBlocks) throws IllegalArgumentException, IOException { 045 try (Table table = RESTServlet.getInstance().getTable(tableName)) { 046 Get get = new Get(rowspec.getRow()); 047 if (rowspec.hasColumns()) { 048 for (byte[] col : rowspec.getColumns()) { 049 byte[][] split = CellUtil.parseColumn(col); 050 if (split.length == 1) { 051 get.addFamily(split[0]); 052 } else if (split.length == 2) { 053 get.addColumn(split[0], split[1]); 054 } else { 055 throw new IllegalArgumentException("Invalid column specifier."); 056 } 057 } 058 } 059 get.setTimeRange(rowspec.getStartTime(), rowspec.getEndTime()); 060 get.setMaxVersions(rowspec.getMaxVersions()); 061 if (filter != null) { 062 get.setFilter(filter); 063 } 064 get.setCacheBlocks(cacheBlocks); 065 Result result = table.get(get); 066 if (result != null && !result.isEmpty()) { 067 valuesI = result.listCells().iterator(); 068 } 069 } catch (DoNotRetryIOException e) { 070 // Warn here because Stargate will return 404 in the case if multiple 071 // column families were specified but one did not exist -- currently 072 // HBase will fail the whole Get. 073 // Specifying multiple columns in a URI should be uncommon usage but 074 // help to avoid confusion by leaving a record of what happened here in 075 // the log. 076 LOG.warn(StringUtils.stringifyException(e)); 077 // Lets get the exception rethrown to get a more meaningful error message than 404 078 if (e instanceof AccessDeniedException) { 079 throw e; 080 } 081 } 082 } 083 084 @Override 085 public void close() { 086 } 087 088 @Override 089 public boolean hasNext() { 090 if (cache != null) { 091 return true; 092 } 093 if (valuesI == null) { 094 return false; 095 } 096 return valuesI.hasNext(); 097 } 098 099 @Override 100 public Cell next() { 101 if (cache != null) { 102 Cell kv = cache; 103 cache = null; 104 return kv; 105 } 106 if (valuesI == null) { 107 return null; 108 } 109 try { 110 return valuesI.next(); 111 } catch (NoSuchElementException e) { 112 return null; 113 } 114 } 115 116 @Override 117 public void putBack(Cell kv) { 118 this.cache = kv; 119 } 120 121 @Override 122 public void remove() { 123 throw new UnsupportedOperationException("remove not supported"); 124 } 125}