Hbase中提供了许多的过滤器接口，以此来对数据进行过滤，使得查询出想要的数据。
行过滤器
针对行信息进行过滤，参数中可以采用前缀匹配、按位与、或、异或以及子串匹配等匹配的方式。同时可以控制EQUAL、NOT_EQUAL选项进行控制筛选数据的条件。
/** * 行过滤器 BinaryComparator NullComparator:是不是空值 * BitComparator:通过BitwiseOp类提供的按位与、或、异或操作进行位级别比较 RegexStringComparator:正则匹配 * SubStringComparator:子串是不是包含进行匹配 */ private static void testRowFilter() { try { HTable table = new HTable(config, "testtable"); Scan scan = new Scan(); scan.addColumn("col1".getBytes(), "name".getBytes()); // 行过滤器 Filter filter = new RowFilter(CompareOp.EQUAL, new BinaryComparator("row2".getBytes())); scan.setFilter(filter); ResultScanner result = table.getScanner(scan); for (Result res : result) { log.info("行过滤器>" + res); } // 正则的行过滤器 Filter filter2 = new RowFilter(CompareOp.EQUAL, new RegexStringComparator(".*.2")); scan.setFilter(filter2); ResultScanner resultRegx = table.getScanner(scan); for (Result res : resultRegx) { log.info("正则>" + res); } Filter filterSubString = new RowFilter(CompareOp.EQUAL, new SubstringComparator("w2")); scan.setFilter(filterSubString); ResultScanner resultSubString = table.getScanner(scan); for (Result res : resultSubString) { log.info("子串>" + res); } table.close(); } catch (IOException e) { log.error(e); } }列族过滤器
根据列族的数据进行筛选，形式和上面的行过滤器类似，通过控制相应的参数中的筛选的条件进行相应的筛选。
/** * 列族过滤器 */ private static void testFamlyFilter() { try { HTable table = new HTable(config, "testtable"); Filter filter = new FamilyFilter(CompareOp.EQUAL, new BinaryComparator("col1".getBytes())); Scan scan = new Scan("row2".getBytes(), filter); ResultScanner result = table.getScanner(scan); for (Result res : result) { log.info(res); } Filter filterNull = new FamilyFilter(CompareOp.EQUAL, new RegexStringComparator(".*.1")); Scan scanNull = new Scan("row2".getBytes(), filterNull); scanNull.addFamily("col1".getBytes()); ResultScanner resultNull = table.getScanner(scanNull); if (resultNull != null) { for (Result res : resultNull) { log.info(res); } } else { log.info("null"); } table.close(); } catch (IOException e) { log.error(e); } }列名过滤器
和上面几个过滤器类似，这里是根据列进行筛选，设置相应的条件后就可以进行相应的筛选了。
/** * 列名过滤器 */ public static void testColumFilter() { try { HTable table = new HTable(config, "testtable"); Filter filter = new QualifierFilter(CompareOp.EQUAL, new BinaryComparator("name".getBytes())); Scan scan = new Scan("row2".getBytes(), filter); ResultScanner result = table.getScanner(scan); for (Result res : result) { log.info(res); } Get get = new Get("row2".getBytes()); get.setFilter(filter); Result resultGet = table.get(get); log.info(resultGet); table.close(); } catch (IOException e) { log.info(e); } }参考列过滤器
参考列过滤器根据列族和列限定符进行筛选，返回与参考列相同时间戳的行的所有键值对。
/** * 参考列过滤器 */ public static void testDependentColumnFilter() { try { HTable table = new HTable(config, "testtable"); Filter filter = new DependentColumnFilter("col1".getBytes(), "name".getBytes(), false); Scan scan = new Scan(); scan.setFilter(filter); ResultScanner resu = table.getScanner(scan); for (Result result : resu) { log.info(result); } Get get = new Get("row2".getBytes()); get.setFilter(filter); Result result = table.get(get); log.info(result); table.close(); } catch (IOException e) { log.error(e); } }单列过滤器
通过一列的值进行判断是不是需要进行过滤。
/** * 单列过滤器 */ public static void testSingleColumnValueFilter() { try { HTable table = new HTable(config, "testtable"); Filter filter = new SingleColumnValueFilter("col1".getBytes(), "name".getBytes(), CompareOp.EQUAL, "wy".getBytes()); Scan scan = new Scan(); scan.setFilter(filter); ResultScanner result = table.getScanner(scan); for (Result res : result) { log.info(res); } Get get = new Get("row2".getBytes()); get.setFilter(filter); Result resultGet = table.get(get); log.info(resultGet); table.close(); } catch (IOException e) { log.info(e); } }前缀过滤器
根据前缀进行匹配行键的数据，本例中给出的是以row为前缀的行的数据。
/** * 前缀过滤器 */ public static void testPrefixFilter() { try { HTable table = new HTable(config, "testtable"); Filter filter = new PrefixFilter("row".getBytes()); Scan scan = new Scan(); scan.setFilter(filter); ResultScanner result = table.getScanner(scan); for (Result res : result) { log.info("res>" + res); } Get get = new Get("row2".getBytes()); Result resultGet = table.get(get); log.info("get>" + resultGet); table.close(); } catch (IOException e) { log.info(e); } }分页过滤器
通过pageFilter设置一页中数据的条数，注意，在重新设置起始行的时候，要使得新的行和数据库中有区别，否则，会死循环无法停止。
/** * 分页过滤器 */ public static void testPageFilter() { try { HTable table = new HTable(config, "testtable"); Filter filter = new PageFilter(10); int totalRows = 0; byte[] lastRow = null; Scan scan = new Scan(); while (true) { scan.setFilter(filter); if (lastRow != null) { // 加上0后表示新的开始防止row的内容一样造成死循环 byte[] startRow = Bytes.add(lastRow, POSTFIX); scan.setStartRow(startRow); } ResultScanner resultScan = table.getScanner(scan); int localRows = 0; Result result = resultScan.next(); while (result != null) { log.info(result); localRows++; totalRows++; lastRow = result.getRow(); result = resultScan.next(); } if (localRows == 0) break; } log.info(totalRows); table.close(); } catch (IOException e) { log.info(e); } }/** * 列分页过滤 */ public static void testColumnPaginationFilter() { try { HTable table = new HTable(config, "testtable"); Filter filter = new ColumnPaginationFilter(5, 10); Scan scan = new Scan(); scan.setFilter(filter); ResultScanner result = table.getScanner(scan); for (Result res : result) { log.info(res); } table.close(); } catch (IOException e) { log.info(e); } }Skip过滤器
与ValueFilter结合使用，如果一行中某一列不符合要求的话直接被过滤掉。
/** * 跳过过滤器 */ public static void testSkipFilter() { try { HTable table = new HTable(config, "testtable"); Filter filt = new ValueFilter(CompareOp.NOT_EQUAL, new BinaryComparator("v".getBytes())); Scan scanValue = new Scan(); scanValue.setFilter(filt); ResultScanner ress = table.getScanner(scanValue); for (Result result : ress) { log.info("<" + result); } Filter filter = new SkipFilter(filt); Scan scan = new Scan(); scan.setFilter(filter); ResultScanner result = table.getScanner(scan); for (Result res : result) { log.info(">" + res); } table.close(); } catch (IOException e) { log.info(e); } }全匹配过滤器
在遇到某个条件之前的数据全部查询出来，直到遇到满足该条件的数据之后结束查询。
/** * 全匹配过滤器 */ public static void testWhileMatch() { try { HTable table = new HTable(config, "testtable"); Filter filt = new RowFilter(CompareOp.NOT_EQUAL, new BinaryComparator("row6".getBytes())); Scan scan = new Scan(); scan.setFilter(filt); ResultScanner results = table.getScanner(scan); for (Result res : results) { log.info(">" + res); } Filter filter = new WhileMatchFilter(filt); scan.setFilter(filter); ResultScanner resultScan = table.getScanner(scan); for (Result res : resultScan) { log.info("<" + res); } table.close(); } catch (IOException e) { log.info(e); } }过滤器组合
可以将上面的过个过滤器放在一个List中，然后形成多个过滤器的组合的形式进行过滤。
/** * 过滤器组合 */ public static void testFilterList() { List<Filter> filterList = new ArrayList<Filter>(); Filter filter1 = new SingleColumnValueFilter("col1".getBytes(), "name".getBytes(), CompareOp.EQUAL, "x".getBytes()); filterList.add(filter1); Filter filter2 = new RowFilter(CompareOp.NOT_EQUAL, new BinaryComparator("row2".getBytes())); filterList.add(filter2); FilterList filters = new FilterList(filterList); Scan scan = new Scan(); scan.setFilter(filters); try { HTable table = new HTable(config, "testtable"); ResultScanner result = table.getScanner(scan); for (Result res : result) { log.info(res); } table.close(); } catch (IOException e) { log.info(e); } }转载注明出处：http://blog.csdn.net/wangyang1354/article/details/53761559
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