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  • HBase Filter 过滤器之 ValueFilter 详解

    前言:本文详细介绍了 HBase ValueFilter 过滤器 Java&Shell API 的使用,并贴出了相关示例代码以供参考。ValueFilter 基于列值进行过滤,在工作中涉及到需要通过HBase 列值进行数据过滤时可以考虑使用它。比较器细节及原理请参照之前的更文:HBase Filter 过滤器之比较器 Comparator 原理及源码学习

    一。Java Api

    头部代码

    /**
     * 用于列值过滤。
     */
    public class ValueFilterDemo {
        private static boolean isok = false;
        private static String tableName = "test";
        private static String[] cfs = new String[]{"f1","f2"};
        private static String[] data = new String[]{
                "row-1:f1:c1:abcdefg", 
    			"row-2:f1:c2:abc", 
    			"row-3:f2:c3:abc123456", 
    			"row-4:f2:c4:1234abc567"
        };
        public static void main(String[] args) throws IOException {
    
            MyBase myBase = new MyBase();
            Connection connection = myBase.createConnection();
            if (isok) {
                myBase.deleteTable(connection, tableName);
                myBase.createTable(connection, tableName, cfs);
                // 造数据
                myBase.putRows(connection, tableName, data);
            }
            Table table = connection.getTable(TableName.valueOf(tableName));
            Scan scan = new Scan();
    

    中部代码

    向右滑动滚动条可查看输出结果。

    1. BinaryComparator 构造过滤器

            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.EQUAL, new BinaryComparator(Bytes.toBytes("abc"))); // [row-2:f1:c2:abc]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.NOT_EQUAL, new BinaryComparator(Bytes.toBytes("abc"))); // [row-1:f1:c1:abcdefg, row-3:f2:c3:abc123456, row-4:f2:c4:1234abc567]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.GREATER, new BinaryComparator(Bytes.toBytes("abc"))); // [row-1:f1:c1:abcdefg, row-3:f2:c3:abc123456]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.GREATER_OR_EQUAL, new BinaryComparator(Bytes.toBytes("abc1"))); // [row-1:f1:c1:abcdefg, row-3:f2:c3:abc123456]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.LESS, new BinaryComparator(Bytes.toBytes("abc"))); // [row-4:f2:c4:1234abc567]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.LESS_OR_EQUAL, new BinaryComparator(Bytes.toBytes("abc"))); // [row-2:f1:c2:abc, row-4:f2:c4:1234abc567]
    

    2. BinaryPrefixComparator 构造过滤器

            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.EQUAL, new BinaryPrefixComparator(Bytes.toBytes("123"))); // [row-4:f2:c4:1234abc567]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.NOT_EQUAL, new BinaryPrefixComparator(Bytes.toBytes("ab"))); // [row-4:f2:c4:1234abc567]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.GREATER, new BinaryPrefixComparator(Bytes.toBytes("ab"))); // [] 只比较prefix长度的字节
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.GREATER_OR_EQUAL, new BinaryPrefixComparator(Bytes.toBytes("ab"))); // [row-1:f1:c1:abcdefg, row-2:f1:c2:abc, row-3:f2:c3:abc123456]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.LESS, new BinaryPrefixComparator(Bytes.toBytes("abc"))); // [row-4:f2:c4:1234abc567]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.LESS_OR_EQUAL, new BinaryPrefixComparator(Bytes.toBytes("abc"))); // [row-1:f1:c1:abcdefg, row-2:f1:c2:abc, row-3:f2:c3:abc123456, row-4:f2:c4:1234abc567]
    

    3. SubstringComparator 构造过滤器

            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.EQUAL, new SubstringComparator("123")); // [row-3:f2:c3:abc123456, row-4:f2:c4:1234abc567]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.NOT_EQUAL, new SubstringComparator("def")); // [row-2:f1:c2:abc, row-3:f2:c3:abc123456, row-4:f2:c4:1234abc567]```
    

    4. RegexStringComparator 构造过滤器

            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.NOT_EQUAL, new RegexStringComparator("4[a-z]")); // [row-1:f1:c1:abcdefg, row-2:f1:c2:abc, row-3:f2:c3:abc123456]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.EQUAL, new RegexStringComparator("4[a-z]")); // [row-4:f2:c4:1234abc567]
            ValueFilter valueFilter = new ValueFilter(CompareFilter.CompareOp.EQUAL, new RegexStringComparator("abc")); // [row-1:f1:c1:abcdefg, row-2:f1:c2:abc, row-3:f2:c3:abc123456, row-4:f2:c4:1234abc567]
    

    尾部代码

    		scan.setFilter(valueFilter);
            ResultScanner scanner = table.getScanner(scan);
            Iterator<Result> iterator = scanner.iterator();
            LinkedList<String> keys = new LinkedList<>();
            while (iterator.hasNext()) {
                String key = "";
                Result result = iterator.next();
                for (Cell cell : result.rawCells()) {
                    byte[] rowkey = CellUtil.cloneRow(cell);
                    byte[] family = CellUtil.cloneFamily(cell);
                    byte[] column = CellUtil.cloneQualifier(cell);
                    byte[] value = CellUtil.cloneValue(cell);
                    key = Bytes.toString(rowkey) + ":" + Bytes.toString(family) + ":" + Bytes.toString(column) + ":" + Bytes.toString(value);
                    keys.add(key);
                }
            }
            System.out.println(keys);
            scanner.close();
            table.close();
            connection.close();
        }
    }
    

    二。Shell Api

    1. BinaryComparator 构造过滤器

    方式一:

    hbase(main):006:0> scan 'test',{FILTER=>"ValueFilter(=,'binary:abc')"}
    ROW                                              COLUMN+CELL                                                                                                                                   
     row-2                                           column=f1:c2, timestamp=1589453592471, value=abc                                                                                              
    1 row(s) in 0.0240 seconds
    
    

    支持的比较运算符:= != > >= < <=,不再一一举例。

    方式二:

    import org.apache.hadoop.hbase.filter.CompareFilter
    import org.apache.hadoop.hbase.filter.BinaryComparator
    import org.apache.hadoop.hbase.filter.ValueFilter
    
    hbase(main):010:0> scan 'test',{FILTER => ValueFilter.new(CompareFilter::CompareOp.valueOf('EQUAL'), BinaryComparator.new(Bytes.toBytes('abc')))}
    ROW                                              COLUMN+CELL                                                                                                                                   
     row-2                                           column=f1:c2, timestamp=1589453592471, value=abc                                                                                              
    1 row(s) in 0.0230 seconds
    

    支持的比较运算符:LESSLESS_OR_EQUALEQUALNOT_EQUALGREATERGREATER_OR_EQUAL,不再一一举例。

    推荐使用方式一,更简洁方便。

    2. BinaryPrefixComparator 构造过滤器

    方式一:

    hbase(main):011:0> scan 'test',{FILTER=>"ValueFilter(=,'binaryprefix:ab')"}
    ROW                                              COLUMN+CELL                                                                                                                                   
     row-1                                           column=f1:c1, timestamp=1589453592471, value=abcdefg                                                                                          
     row-2                                           column=f1:c2, timestamp=1589453592471, value=abc                                                                                              
     row-3                                           column=f2:c3, timestamp=1589453592471, value=abc123456                                                                                        
    3 row(s) in 0.0430 seconds
    

    方式二:

    import org.apache.hadoop.hbase.filter.CompareFilter
    import org.apache.hadoop.hbase.filter.BinaryPrefixComparator
    import org.apache.hadoop.hbase.filter.ValueFilter
    
    hbase(main):013:0> scan 'test',{FILTER => ValueFilter.new(CompareFilter::CompareOp.valueOf('EQUAL'), BinaryPrefixComparator.new(Bytes.toBytes('ab')))}
    ROW                                              COLUMN+CELL                                                                                                                                   
     row-1                                           column=f1:c1, timestamp=1589453592471, value=abcdefg                                                                                          
     row-2                                           column=f1:c2, timestamp=1589453592471, value=abc                                                                                              
     row-3                                           column=f2:c3, timestamp=1589453592471, value=abc123456                                                                                        
    3 row(s) in 0.0440 seconds
    

    其它同上。

    3. SubstringComparator 构造过滤器

    方式一:

    hbase(main):014:0> scan 'test',{FILTER=>"ValueFilter(=,'substring:123')"}
    ROW                                              COLUMN+CELL                                                                                                                                   
     row-3                                           column=f2:c3, timestamp=1589453592471, value=abc123456                                                                                        
     row-4                                           column=f2:c4, timestamp=1589453592471, value=1234abc567                                                                                       
    2 row(s) in 0.0340 seconds
    

    方式二:

    import org.apache.hadoop.hbase.filter.CompareFilter
    import org.apache.hadoop.hbase.filter.SubstringComparator
    import org.apache.hadoop.hbase.filter.ValueFilter
    
    hbase(main):016:0> scan 'test',{FILTER => ValueFilter.new(CompareFilter::CompareOp.valueOf('EQUAL'), SubstringComparator.new('123'))}
    ROW                                              COLUMN+CELL                                                                                                                                   
     row-3                                           column=f2:c3, timestamp=1589453592471, value=abc123456                                                                                        
     row-4                                           column=f2:c4, timestamp=1589453592471, value=1234abc567                                                                                       
    2 row(s) in 0.0240 seconds
    

    区别于上的是这里直接传入字符串进行比较,且只支持EQUALNOT_EQUAL两种比较符。

    4. RegexStringComparator 构造过滤器

    import org.apache.hadoop.hbase.filter.CompareFilter
    import org.apache.hadoop.hbase.filter.RegexStringComparator
    import org.apache.hadoop.hbase.filter.ValueFilter
    
    hbase(main):018:0> scan 'test',{FILTER => ValueFilter.new(CompareFilter::CompareOp.valueOf('EQUAL'), RegexStringComparator.new('4[a-z]'))}
    ROW                                              COLUMN+CELL                                                                                                                                   
     row-4                                           column=f2:c4, timestamp=1589453592471, value=1234abc567                                                                                       
    1 row(s) in 0.0290 seconds
    

    该比较器直接传入字符串进行比较,且只支持EQUALNOT_EQUAL两种比较符。若想使用第一种方式可以传入regexstring试一下,我的版本有点低暂时不支持,不再演示了。

    注意这里的正则匹配指包含关系,对应底层find()方法。

    ValueFilter 不支持使用 LongComparator 比较器,且 BitComparatorNullComparator 比较器用之甚少,也不再介绍。

    查看文章全部源代码请访以下GitHub地址:

    https://github.com/zhoupengbo/demos-bigdata/blob/master/hbase/hbase-filters-demos/src/main/java/com/zpb/demos/ValueFilterDemo.java
    

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  • 原文地址:https://www.cnblogs.com/zpb2016/p/12921416.html
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