HBase中使用過濾器篩選數據

一、過濾器能干什么

HBase為篩選數據提供了一組過濾器，通過過濾器可以在HBase中的數據的多個維度(行，列，數據版本)上進行對數據的篩選操作。
通常來說，通過行鍵、列來篩選數據的應用場景較多。

二、常見的過濾器

基於行的過濾器

PrefixFilter: 行的前綴匹配
PageFilter: 基於行的分頁

基於列的過濾器

ColumnPrefixFilter: 列前綴匹配
FirstKeyOnlyFilter: 只返回每一行的第一列

基於單元值的過濾器

KeyOnlyFilter: 返回的數據不包括單元值，只包含行鍵與列
TimestampsFilter: 根據數據的時間戳版本進行過濾

基於列和單元值的過濾器

SingleColumnValueFilter: 對該列的單元值進行比較過濾
SingleColumnValueExcludeFilter: 對該列的單元值進行比較過濾

比較過濾器

比較過濾器通常需要一個比較運算符以及一個比較器來實現過濾
RowFilter、 FamilyFilter、 QualifierFilter、 ValueFilter
常見過濾器總結

過濾器(Filter) 功能

• RowFilter 篩選出匹配的所有的行
• PrefixFilter 篩選出具有特定前綴的行鍵的數據
• KeyOnlyFilter 只返回每行的行鍵，值全部為空
• ColumnPrefixFilter 按照列名的前綴來篩選單元格
• ValueFilter 按照具體的值來篩選單元格的過濾器
• TimestampsFilter 根據數據的時間戳版本進行過濾
• FilterList 用於綜合使用多個過濾器

三、開發演示

/**
* @title HBaseFilterTest
* @date 2019/12/9 15:01
* @description 嘗試使用過濾器
*/
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指必須通過所有的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"));// 前綴為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();
}
}
}