Hbase过滤器

	package HbaseApi;
	
	import org.apache.hadoop.conf.Configuration;
	import org.apache.hadoop.hbase.*;
	import org.apache.hadoop.hbase.client.*;
	import org.apache.hadoop.hbase.filter.*;
	import org.apache.hadoop.hbase.util.Bytes;
	import org.datanucleus.store.types.backed.ArrayList;
	
	import java.io.IOException;
	import java.sql.Array;
	import java.util.Arrays;
	
	import static org.apache.hadoop.hbase.filter.CompareFilter.CompareOp.EQUAL;
	import static org.apache.hadoop.hbase.filter.CompareFilter.CompareOp.LESS;
	
	public class FilterDemo {
	
	
	    private static void scan(Filter filter,Table table) throws IOException {
	
	        Scan scan=new Scan();//new 一个对象
	        scan.setFilter(filter);//设置过滤器
	        ResultScanner scanner = table.getScanner(scan);//返回table的执行结果
	
	        int rowcount=0;
	        for(Result result:scanner)//遍历结果
	        {
	            CellScanner cellScanner = result.cellScanner();//拿到cell
	            while (cellScanner.advance())
	            {
	                Cell current = cellScanner.current();//拿到当前的cell
	                byte[] rowArray = current.getRowArray();//拿到rowkey
	                byte[] familyArray = current.getFamilyArray();//拿到列簇
	                byte[] qualifierArray = current.getQualifierArray();//拿到当前的列
	                byte[] valueArray = current.getValueArray();//拿到值
	                String s2 = Bytes.toString(CellUtil.cloneRow(current));
	                String s = Bytes.toString(CellUtil.cloneFamily(current));//拿到列簇的字符串
	                String s1 = Bytes.toString(CellUtil.cloneQualifier(current));//拿到列的字符串
	                String s3 = Bytes.toString(CellUtil.cloneValue(current));//拿到value的值
	                System.out.println(s2+"-->"+s+"-->"+s1+"-->"+s3);
	               }
	            rowcount++;
	        }
	
	        System.out.println(rowcount);
	        scanner.close();
	    }
	
	    public static void main(String[] args) throws IOException {
	
	
	        Configuration conf = HBaseConfiguration.create();//拿到hbase的配置实例
	        conf.set("hbase.zookeeper.quorum", "192.168.1.137,192.168.1.138,192.168.1.139");//指定zookeepr连接的所在地
	        conf.set("hbase.zookeeper.property.clientPort", "2181");//指定zk的端口号，默认就是2181,如果你将zk的默认端口号改了，那么就需要重新指定为你改的那个端口好
	
	        conf.set("zookeeper.znode.parent", "/hbase-unsecure");//指定Hbase在zk中的父目录，非常重要，如果不是/hbase则显示的指定出来
	
	        //加载配置,获取到hbase的连接
	        Connection connection = ConnectionFactory.createConnection(conf);
	        Table bg06 = connection.getTable(TableName.valueOf("student"));
	//====keyOnlyFilter
	/*      //这个过滤器唯一的功能就是只返回每行的行键，值全部为空，这对于只关注于行键的应用场景来说非常合适，这样忽略掉其值就可以减少传递到客户端的数据量，能起到一定的优化作用
	        KeyOnlyFilter keyOnlyFilter = new KeyOnlyFilter();//该过滤器没有任何参数，作用很单一，将所有的cell值变成空。经常用于Row个数统计
	        scan(keyOnlyFilter,bg06);
	*/
	//====FirstKeyOnlyFilter
	/*      //如果你只想返回的结果集中只包含第一列的数据，那么这个过滤器能够满足你的要求。它在找到每行的第一列之后会停止扫描，从而使扫描的性能也得到了一定的提升
	        FirstKeyOnlyFilter firstKeyOnlyFilter = new FirstKeyOnlyFilter();//该过滤器没有任何参数，作用很单一，只获取到每个rowkey的第一个cell即当俩个rowkey相同时则只显示第一个cell区间。经常用于Row个数统计
	        scan(firstKeyOnlyFilter,bg06);
	*/
	//====TimestampsFilter
	/*
	        TimestampsFilter timestampsFilter = new TimestampsFilter(Arrays.asList(1551442681243l));//时间过滤器
	        scan(timestampsFilter,bg06);
	*/
	
	
	        //====3、rowFilter  这是rowkey的比较 它就需要参数，一个是比较操作符，一个是比较器。
	      /**
	         * 比较操作符就是我们常说的>,<,<=,>=,!=,== 等等，对应的类是
	         * CompareFilter.CompareOp  里面有N多个枚举。
	         *    LESS,LESS_OR_EQUAL,EQUAL,NOT_EQUAL,GREATER_OR_EQUAL,GREATER,NO_OP
	         *
	         *  还有比较器：BinaryComparator、BinaryPrefixComparator、LongComparator、RegexStringComparator
	         *  SubstringComparator.
	         *
	         **/
	//      //==BinaryComparator二进制比较过滤器 0 01 03 2
	//        BinaryComparator binaryComparator=new BinaryComparator("1".getBytes());
	//        RowFilter rowFilter = new RowFilter(EQUAL,binaryComparator);//按二进制比较，采用 Bytes.compareTo(byte[])
	//        scan(rowFilter,bg06);
	////        003-->info3-->name-->ooooo
	////        1
	
	
	        //==BinaryPrefixComparator二进制前缀顾虑器
	//        BinaryPrefixComparator binaryPrefixComparator = new BinaryPrefixComparator("h".getBytes());//二进制前缀比较器 例如 rui和ruiii 的前缀都是rui
	//        RowFilter rowFilter = new RowFilter(CompareFilter.CompareOp.LESS, binaryPrefixComparator);
	//        scan(rowFilter,bg06);
	////        003-->info3-->name-->ooooo
	////        127-->info-->age-->333
	////        127-->info-->name-->333
	////        2
	
	        //===longcomparator长度过滤器（long类型）
	        LongComparator longComparator = new LongComparator(5);//长度为5
	        RowFilter rowFilter = new RowFilter(CompareFilter.CompareOp.LESS, longComparator);//小于5的rowkey
	        scan(rowFilter,bg06);
	//        //Exception in thread "main" java.lang.RuntimeException: org.apache.hadoop.hbase.DoNotRetryIOException: Failed after retry of OutOfOrderScannerNextException: was there a rpc timeout?
	
	        //==RegexStringComparator正则过滤器
	//        RegexStringComparator name = new RegexStringComparator("^h");//提供一个正则的比较器，仅支持 EQUAL 和 NOT_EQUAL 运算符
	//        RowFilter rowFilter = new RowFilter(CompareFilter.CompareOp.EQUAL, name);//查找以h为开头的rowkey
	//        scan(rowFilter,bg06);
	//        //hello-->info-->hhh-->this is methis is methis is me
	//        //1
	
	        //===QualifierFilter列过滤器
	//        BinaryPrefixComparator binaryPrefixComparator = new BinaryPrefixComparator("name".getBytes());//列过滤器
	//        QualifierFilter qualifierFilter = new QualifierFilter(CompareFilter.CompareOp.EQUAL,binaryPrefixComparator);//查找列名为name的rowkey
	//        scan(qualifierFilter,bg06);
	////        003-->info3-->name-->ooooo
	////        127-->info-->name-->333
	////        2
	
	
	
	        //===SubstringComparator
	//        SubstringComparator substringComparator = new SubstringComparator("127");//包含127的过滤器
	//        RowFilter rowFilter = new RowFilter(CompareFilter.CompareOp.EQUAL, substringComparator);//查看包含127的rowkey
	//        scan(rowFilter,bg06);
	////        127-->info-->age-->333
	////        127-->info-->name-->333
	////        1
	
	    }
	
	}