使用RowFilter无法使用按键查询HBase表 [英] Query HBase table by key using RowFilter not working
问题描述
我有一个HBase表（来自java），我想通过键列表查询表。我做了以下，但它不工作。
mFilterFeatureIt = mFeatureSet.iterator（）;
FilterList filterList = new FilterList（FilterList.Operator.MUST_PASS_ONE）;
while（mFilterFeatureIt.hasNext（））{
long myfeatureId = mFilterFeatureIt.next（）;
System.out.println（FeatureId：+ myfeatureId +，）;
RowFilter filter = new RowFilter（CompareOp.EQUAL，new BinaryComparator（Bytes.toBytes（myfeatureId）））;
filterList.addFilter（filter）;
}
outputMap = HbaseUtils.getHbaseData（mytable，filterList）;
System.out.println（outputMap map的大小：+ outputMap.szie（））;
public static Map< String，Map< String，String>> getHbaseData（String table，FilterList filter）{
Map< String，Map< String，String>> data = new HashMap< String，Map< String，String>>（）;
HTable htable = null;
尝试{
htable = new HTable（HTableConfiguration.getHTableConfiguration（），table）;
扫描扫描=新扫描（）;
scan.setFilter（filter）;
ResultScanner resultScanner = htable.getScanner（scan）;
迭代器<结果> results = resultScanner.iterator（）;
while（results.hasNext（））{
Result result = results.next（）;
String rowId = Bytes.toString（result.getRow（））;
列表< KeyValue> columns = result.list（）;
if（null！= columns）{
HashMap< String，String> colData = new HashMap< String，String>（）; （KeyValue列：列）{
colData.put（Bytes.toString（column.getFamily（））+：+ Bytes.toString（column.getQualifier（）），Bytes.toString（ column.getValue（）））;
}
data.put（rowId，colData）;
$ catch（IOException e）{
e.printStackTrace（）;
} finally {
if（htable！= null）
try {
htable.close（）;
} catch（IOException e）{
e.printStackTrace（）;
}
}
返回数据;
}
FeatureId：80515900，
FeatureId：80515901，
FeatureId：80515902，
outputMap映射的大小：0
我看到特性id的值是我想要，但即使key存在于hbase表中，我也总能得到上面的输出结果。任何人都可以告诉我，我做错了什么？
编辑：
我发布了hbase util方法的代码，以便您可以指向我在那里的任何错误。
我正在尝试执行一个与 select * FROM mytable相同的SQL，其中featureId位于（80515900,80515901,80515902）我在HBase中实现相同的想法是为每个featureId创建一个带有一个过滤器的过滤器列表。这是正确的吗？
以下是我的表格内容
扫描'mytable'，{COLUMNS => ['sample：tag_count']}
80515900 column = sample：tag_count，timestamp = 1339304052748，value = 4
80515901 column = sample：tag_count，timestamp = 1339304052748，value = 0
80515902 column = sample：tag_count，timestamp = 1339304052748，value = 3
80515903 column = sample：tag_count，timestamp = 1339304052748，value = 1
80515904 column = sample：tag_count，timestamp = 1339304052748，value = 2
在将数据插入到hbase时，它不返回任何数据，
key的数据类型是'String'（来自您的扫描结果）&在获取时，在RowFilter中传递的值具有长数据类型。使用这个过滤器：
$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ .toString（））））;
I have a HBase table (from java) and i want to query the table by list of keys. I did the following, but its not working.
mFilterFeatureIt = mFeatureSet.iterator();
FilterList filterList=new FilterList(FilterList.Operator.MUST_PASS_ONE);
while (mFilterFeatureIt.hasNext()) {
long myfeatureId = mFilterFeatureIt.next();
System.out.println("FeatureId:"+myfeatureId+" , ");
RowFilter filter = new RowFilter(CompareOp.EQUAL,new BinaryComparator(Bytes.toBytes(myfeatureId)) );
filterList.addFilter(filter);
}
outputMap = HbaseUtils.getHbaseData("mytable", filterList);
System.out.println("Size of outputMap map:"+ outputMap.szie());
public static Map<String, Map<String, String>> getHbaseData(String table, FilterList filter) {
Map<String, Map<String, String>> data = new HashMap<String, Map<String, String>>();
HTable htable = null;
try {
htable = new HTable(HTableConfiguration.getHTableConfiguration(),table);
Scan scan = new Scan();
scan.setFilter(filter);
ResultScanner resultScanner = htable.getScanner(scan);
Iterator<Result> results = resultScanner.iterator();
while (results.hasNext()) {
Result result = results.next();
String rowId = Bytes.toString(result.getRow());
List<KeyValue> columns = result.list();
if (null != columns) {
HashMap<String, String> colData = new HashMap<String, String>();
for (KeyValue column : columns) {
colData.put(Bytes.toString(column.getFamily()) + ":"+ Bytes.toString(column.getQualifier()),Bytes.toString(column.getValue()));
}
data.put(rowId, colData);
}
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (htable != null)
try {
htable.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return data;
}
FeatureId:80515900 , FeatureId:80515901 , FeatureId:80515902 ,
Size of outputMap map: 0
I see that value of feature id is what i want , but I always get the above output even if the key is present in the hbase table. Can anyone tell me what am i doing wrong ?
EDIT: I posted the code for my hbase util method too above, so that you can point me to any bugs there.
I am trying to do an SQL equivalent of select * FROM mytable where featureId in (80515900, 80515901, 80515902) My idea to achieve the same in HBase was to create a filter list with one filter for each featureId. Is that correct ?
Here is the content of my table
scan 'mytable', {COLUMNS => ['sample:tag_count'] }
80515900 column=sample:tag_count, timestamp=1339304052748, value=4
80515901 column=sample:tag_count, timestamp=1339304052748, value=0
80515902 column=sample:tag_count, timestamp=1339304052748, value=3
80515903 column=sample:tag_count, timestamp=1339304052748, value=1
80515904 column=sample:tag_count, timestamp=1339304052748, value=2
Its not returning any data as while inserting the data into hbase,
the data-type for key is 'String' (from your scan result) & while fetching, the value passed in RowFilter has 'long' data type. Use this filter:
RowFilter filter = new RowFilter(CompareOp.EQUAL,new
BinaryComparator(Bytes.toBytes(myfeatureId.toString())) );
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