hbase过滤查询的两种方式

如果你在hbase表中存在一些特征相同的记录，实际上就可以通过设置Filter的方式进行检索过滤。

比如这个特征是前缀相同。

ROW COLUMN+CELL 003_8618722111005_460014004369494 column=info:sex, timestamp=1318853623294, value=male

Jerry1 column=info:sex, timestamp=1318917602868, value=male 003_8618722111005_460014004569494
column=info:sex, timestamp=1318917789851, value=male

可以发现这三条记录都是以Jerry开头的row key.

那么我们如何检索呢。很简单。

如果是在hbase shell中

scan ‘scores’, {FILTER => org.apache.hadoop.hbase.filter.PrefixFilter.new(org.apache.hadoop.hbase.util.Bytes.toBytes(‘003_8618722111005_’))}

或者

scan 'MsisdnImsi',{STARTROW=>"003_8618722111005_460014004369494",STOPROW=>"003_8618722111005_9"}

如果是java 客户端

<pre name="code" class="java">public void scaneByPrefixFilter(String tablename, String rowPrifix) {
try {
HTable table = new HTable(conf, tablename);
Scan s = new Scan();
s.setFilter(new PrefixFilter(rowPrifix.getBytes()));
ResultScanner rs = table.getScanner(s);
for (Result r : rs) {
KeyValue[] kv = r.raw();
for (int i = 0; i < kv.length; i++) {
System.out.print(new String(kv[i].getRow()) + "  ");
System.out.print(new String(kv[i].getFamily()) + ":");
System.out.print(new String(kv[i].getQualifier()) + "  ");
System.out.print(kv[i].getTimestamp() + "  ");
System.out.println(new String(kv[i].getValue()));
}
}
} catch (IOException e) {
e.printStackTrace();
}
}

或者：

<pre name="code" class="java">public static void getInfo(String str) {
//根据分区规则 取模
long mod = Long.valueOf(str) % DataType.getAsInt(6);
String tmp = "";
if (mod > 9)
{
tmp = "0" + mod;
}
else
{
tmp = "00" + mod;
}
//参考scan 'MsisdnImsi',{STARTROW=>"003_8618722111005_460014004369494",STOPROW=>"003_8618722111005_9"}</span>
String startRow = tmp + "_" + str;
String stopRow = tmp + "_" + str + "_9";

logger.info("----------------------   startRow : "+startRow+" ---------------------");
logger.info("----------------------   stopRow : "+stopRow+" ---------------------");

ResultScanner scanner = null;
try
{
// 从表池中取出HBASE表对象
HTableInterface table = getTable("testtable");
byte[] family   = Bytes.toBytes("F");
byte[] column   = Bytes.toBytes("A");
// 获取筛选对象
Scan scan = new Scan();
scan.setStartRow(getBytes(startRow));
scan.setStopRow(getBytes(stopRow));
scan.addColumn(family, column);
// 给筛选对象放入过滤器(true标识分页,具体方法在下面)
scan.setCacheBlocks(false);
scanner = table.getScanner(scan);
// 遍历扫描器对象， 并将需要查询出来的数据row key取出
for (Result result : scanner) {
for (KeyValue kv : result.list()) {
String key = Bytes.toStringBinary(kv.getRow());
String value = HbaseVO.deserialize(kv.getValue()).insertTime;
//do something
}
}
}
catch (Exception e)
{
e.printStackTrace();
logger.error("查询hbase异常！ ",e);
}
finally
{
closeScanner(scanner);
}
}