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引言：過濾器的類型很多，但是可以分為兩大類

• 比較過濾器
• 專用過濾器

過濾器的作用是在服務(wù)端判斷數(shù)據(jù)是否滿足條件，然后只將滿足條件的數(shù)據(jù)返回給客戶端；

hbase過濾器的比較運(yùn)算符：

LESS < LESS_OR_EQUAL <= EQUAL = NOT_EQUAL <> GREATER_OR_EQUAL >= GREATER > NO_OP 排除所有

Hbase過濾器的比較器（指定比較機(jī)制）：

BinaryComparator 按字節(jié)索引順序比較指定字節(jié)數(shù)組，采用Bytes.compareTo(byte[]) BinaryPrefixComparator 跟前面相同，只是比較左端的數(shù)據(jù)是否相同 NullComparator 判斷給定的是否為空 BitComparator 按位比較 RegexStringComparator 提供一個(gè)正則的比較器，僅支持 EQUAL 和非EQUAL SubstringComparator 判斷提供的子串是否出現(xiàn)在value中。

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1、比較過濾器

1.1、行鍵過濾器RowFilter

Filter filter1 = new RowFilter(CompareOp.LESS_OR_EQUAL, new BinaryComparator(Bytes.toBytes("row-22"))); scan.setFilter(filter1);

1.2、列族過濾器FamilyFilter

Filter filter1 = new FamilyFilter(CompareFilter.CompareOp.LESS, new BinaryComparator(Bytes.toBytes("colfam3"))); scan.setFilter(filter1);

1.3、列過濾器QualifierFilter

filter = new QualifierFilter(CompareFilter.CompareOp.LESS_OR_EQUAL, new BinaryComparator(Bytes.toBytes("col-2"))); scan.setFilter(filter1);

1.4、值過濾器ValueFilter

Filter filter = new ValueFilter(CompareFilter.CompareOp.EQUAL, new SubstringComparator(".4") ); scan.setFilter(filter1);

2、專用過濾器

2.1、單列值過濾器SingleColumnValueFilter

返回滿足條件的整行

SingleColumnValueFilter filter = new SingleColumnValueFilter( Bytes.toBytes("colfam1"), Bytes.toBytes("col-5"), CompareFilter.CompareOp.NOT_EQUAL, new SubstringComparator("val-5")); filter.setFilterIfMissing(true); //如果不設(shè)置為true，則那些不包含指定column的行也會(huì)返回 scan.setFilter(filter1);

2.2、SingleColumnValueExcludeFilter與SingleColumnValueFilter相反

2.3、前綴過濾器PrefixFilter

針對行鍵

Filter filter = new PrefixFilter(Bytes.toBytes("row1")); scan.setFilter(filter1);

2.4、列前綴過濾器ColumnPrefixFilter

Filter filter = new ColumnPrefixFilter(Bytes.toBytes("qual2")); scan.setFilter(filter1);

2.5、分頁過濾器PageFilter

public static void main(String[] args) throws Exception {Configuration conf = HBaseConfiguration.create();conf.set("hbase.zookeeper.quorum", "spark01:2181,spark02:2181,spark03:2181");String tableName = "testfilter"; String cfName = "f1"; final byte[] POSTFIX = new byte[] { 0x00 }; HTable table = new HTable(conf, tableName); Filter filter = new PageFilter(3); byte[] lastRow = null; int totalRows = 0; while (true) { Scan scan = new Scan(); scan.setFilter(filter); if(lastRow != null){ //注意這里添加了POSTFIX操作，用來重置掃描邊界 byte[] startRow = Bytes.add(lastRow,POSTFIX); scan.setStartRow(startRow); } ResultScanner scanner = table.getScanner(scan); int localRows = 0; Result result; while((result = scanner.next()) != null){ System.out.println(localRows++ + ":" + result); totalRows ++; lastRow = result.getRow(); } scanner.close(); if(localRows == 0) break; } System.out.println("total rows:" + totalRows); }

3、多種過濾條件使用

/*** 多種過濾條件的使用方法* @throws Exception*/@Testpublic void testScan() throws Exception{HTable table = new HTable(conf, "person_info".getBytes());Scan scan = new Scan(Bytes.toBytes("person_rk_bj_zhang_000001"), Bytes.toBytes("person_rk_bj_zhang_000002"));//前綴過濾器----針對行鍵Filter filter = new PrefixFilter(Bytes.toBytes("rk"));//行過濾器 ---針對行鍵ByteArrayComparable rowComparator = new BinaryComparator(Bytes.toBytes("person_rk_bj_zhang_000001"));RowFilter rf = new RowFilter(CompareOp.LESS_OR_EQUAL, rowComparator);/*** 假設(shè)rowkey格式為：創(chuàng)建日期_發(fā)布日期_ID_TITLE* 目標(biāo)：查找 發(fā)布日期 為 2014-12-21 的數(shù)據(jù)*/rf = new RowFilter(CompareOp.EQUAL , new SubstringComparator("_2014-12-21_"));//單值過濾器1完整匹配字節(jié)數(shù)組new SingleColumnValueFilter("base_info".getBytes(), "name".getBytes(), CompareOp.EQUAL, "zhangsan".getBytes());//單值過濾器2 匹配正則表達(dá)式ByteArrayComparable comparator = new RegexStringComparator("zhang.");new SingleColumnValueFilter("info".getBytes(), "NAME".getBytes(), CompareOp.EQUAL, comparator);//單值過濾器3匹配是否包含子串,大小寫不敏感comparator = new SubstringComparator("wu");new SingleColumnValueFilter("info".getBytes(), "NAME".getBytes(), CompareOp.EQUAL, comparator);//鍵值對元數(shù)據(jù)過濾-----family過濾----字節(jié)數(shù)組完整匹配FamilyFilter ff = new FamilyFilter(CompareOp.EQUAL , new BinaryComparator(Bytes.toBytes("base_info")) //表中不存在inf列族，過濾結(jié)果為空);//鍵值對元數(shù)據(jù)過濾-----family過濾----字節(jié)數(shù)組前綴匹配ff = new FamilyFilter(CompareOp.EQUAL , new BinaryPrefixComparator(Bytes.toBytes("inf")) //表中存在以inf打頭的列族info，過濾結(jié)果為該列族所有行);//鍵值對元數(shù)據(jù)過濾-----qualifier過濾----字節(jié)數(shù)組完整匹配filter = new QualifierFilter(CompareOp.EQUAL , new BinaryComparator(Bytes.toBytes("na")) //表中不存在na列，過濾結(jié)果為空);filter = new QualifierFilter(CompareOp.EQUAL , new BinaryPrefixComparator(Bytes.toBytes("na")) //表中存在以na打頭的列name，過濾結(jié)果為所有行的該列數(shù)據(jù));//基于列名(即Qualifier)前綴過濾數(shù)據(jù)的ColumnPrefixFilterfilter = new ColumnPrefixFilter("na".getBytes());//基于列名(即Qualifier)多個(gè)前綴過濾數(shù)據(jù)的MultipleColumnPrefixFilterbyte[][] prefixes = new byte[][] {Bytes.toBytes("na"), Bytes.toBytes("me")};filter = new MultipleColumnPrefixFilter(prefixes);//為查詢設(shè)置過濾條件scan.setFilter(filter);scan.addFamily(Bytes.toBytes("base_info"));//一行 // Result result = table.get(get);//多行的數(shù)據(jù)ResultScanner scanner = table.getScanner(scan);for(Result r : scanner){/**for(KeyValue kv : r.list()){String family = new String(kv.getFamily());System.out.println(family);String qualifier = new String(kv.getQualifier());System.out.println(qualifier);System.out.println(new String(kv.getValue()));}*///直接從result中取到某個(gè)特定的valuebyte[] value = r.getValue(Bytes.toBytes("base_info"), Bytes.toBytes("name"));System.out.println(new String(value));}table.close();}

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