HBase中使用过滤器筛选数据

一、过滤器能干什么

HBase为筛选数据提供了一组过滤器，通过过滤器可以在HBase中的数据的多个维度(行，列，数据版本)上进行对数据的筛选操作。
通常来说，通过行键、列来筛选数据的应用场景较多。

二、常见的过滤器

基于行的过滤器

PrefixFilter: 行的前缀匹配
PageFilter: 基于行的分页

基于列的过滤器

ColumnPrefixFilter: 列前缀匹配
FirstKeyOnlyFilter: 只返回每一行的第一列

基于单元值的过滤器

KeyOnlyFilter: 返回的数据不包括单元值，只包含行键与列
TimestampsFilter: 根据数据的时间戳版本进行过滤

基于列和单元值的过滤器

SingleColumnValueFilter: 对该列的单元值进行比较过滤
SingleColumnValueExcludeFilter: 对该列的单元值进行比较过滤

比较过滤器

比较过滤器通常需要一个比较运算符以及一个比较器来实现过滤
RowFilter、 FamilyFilter、 QualifierFilter、 ValueFilter
常见过滤器总结

过滤器(Filter) 功能

• RowFilter 筛选出匹配的所有的行
• PrefixFilter 筛选出具有特定前缀的行键的数据
• KeyOnlyFilter 只返回每行的行键，值全部为空
• ColumnPrefixFilter 按照列名的前缀来筛选单元格
• ValueFilter 按照具体的值来筛选单元格的过滤器
• TimestampsFilter 根据数据的时间戳版本进行过滤
• FilterList 用于综合使用多个过滤器

三、开发演示

/**
* @title HBaseFilterTest
* @date 2019/12/9 15:01
* @description 尝试使用过滤器
*/
public class HBaseFilterTest {

@Test
public void createTable(){
HBaseUtil.createTable("FileTable", new String[]{"fileInfo", "saveInfo"});
}

@Test
public void addFileDetails(){
HBaseUtil.putRow("FileTable", "rowkey1", "fileInfo", "name", "file1.txt");
HBaseUtil.putRow("FileTable", "rowkey1", "fileInfo", "type", "txt");
HBaseUtil.putRow("FileTable", "rowkey1", "fileInfo", "size", "1024");
HBaseUtil.putRow("FileTable", "rowkey1", "saveInfo", "creator", "suiwo1");
HBaseUtil.putRow("FileTable", "rowkey2", "fileInfo", "name", "file2.jpg");
HBaseUtil.putRow("FileTable", "rowkey2", "fileInfo", "type", "jpg");
HBaseUtil.putRow("FileTable", "rowkey2", "fileInfo", "size", "2048");
HBaseUtil.putRow("FileTable", "rowkey2", "saveInfo", "creator", "suiwo3");
HBaseUtil.putRow("FileTable", "rowkey3", "fileInfo", "name", "file3.jpg");
HBaseUtil.putRow("FileTable", "rowkey3", "fileInfo", "type", "jpg");
HBaseUtil.putRow("FileTable", "rowkey3", "fileInfo", "size", "2048");
HBaseUtil.putRow("FileTable", "rowkey3", "saveInfo", "creator", "suiwo3");
}

/**
* rowkey = rowkey1
* fileName = file1.txt
*/
@Test
public void rowFilterTest(){
Filter filter = new RowFilter(CompareFilter.CompareOp.EQUAL, new BinaryComparator(Bytes.toBytes("rowkey1")));

// MUST_PASS_ALL指必须通过所有的Filter
FilterList filterList = new FilterList(FilterList.Operator.MUST_PASS_ALL, Arrays.asList(filter));

ResultScanner scanner = HBaseUtil.getScanner("FileTable","rowkey1","rowkey3", filterList);

if(scanner != null){
scanner.forEach(result -> {
System.out.println("rowkey = " + Bytes.toString(result.getRow()));
System.out.println("fileName = " + Bytes.toString(result.getValue(Bytes.toBytes("fileInfo"), Bytes.toBytes("name"))));
});
scanner.close();
}
}

/**
* rowkey = rowkey2
* fileName = file2.jpg
*/
@Test
public void prefixFilterTest(){
Filter filter = new PrefixFilter(Bytes.toBytes("rowkey2"));
FilterList filterList = new FilterList(FilterList.Operator.MUST_PASS_ALL, Arrays.asList(filter));
ResultScanner scanner = HBaseUtil.getScanner("FileTable","rowkey1","rowkey3", filterList);

if(scanner != null){
scanner.forEach(result -> {
System.out.println("rowkey = " + Bytes.toString(result.getRow()));
System.out.println("fileName = " + Bytes.toString(result.getValue(Bytes.toBytes("fileInfo"), Bytes.toBytes("name"))));
});
scanner.close();
}
}

/**
* rowkey = rowkey1
* fileName = ���
* rowkey = rowkey2
* fileName = ���
*/
@Test
public void keyOnlyFilterTest(){
Filter filter = new KeyOnlyFilter(true);
FilterList filterList = new FilterList(FilterList.Operator.MUST_PASS_ALL, Arrays.asList(filter));
ResultScanner scanner = HBaseUtil.getScanner("FileTable","rowkey1","rowkey3", filterList);

if(scanner != null){
scanner.forEach(result -> {
System.out.println("rowkey = " + Bytes.toString(result.getRow()));
System.out.println("fileName = " + Bytes.toString(result.getValue(Bytes.toBytes("fileInfo"), Bytes.toBytes("name"))));
});
scanner.close();
}
}

/**
* rowkey = rowkey1
* fileName = file1.txt
* fileType = null
* rowkey = rowkey2
* fileName = file2.jpg
* fileType = null
*/
@Test
public void columnPrefixFilterTest(){
Filter filter = new ColumnPrefixFilter(Bytes.toBytes("nam"));// 前缀为nam
FilterList filterList = new FilterList(FilterList.Operator.MUST_PASS_ALL, Arrays.asList(filter));
ResultScanner scanner = HBaseUtil.getScanner("FileTable","rowkey1","rowkey3", filterList);

if(scanner != null){
scanner.forEach(result -> {
System.out.println("rowkey = " + Bytes.toString(result.getRow()));
System.out.println("fileName = " + Bytes.toString(result.getValue(Bytes.toBytes("fileInfo"), Bytes.toBytes("name"))));
System.out.println("fileType = " + Bytes.toString(result.getValue(Bytes.toBytes("fileInfo"), Bytes.toBytes("type"))));
});
scanner.close();
}
}
}