过滤器的操作符
LESS < LESS_OR_EQUAL <=EQUAL = NOT_EQUAL <> GREATER_OR_EQUAL >=GREATER > NO_OP no operation
比较器
BinaryComparator 按字节索引顺序比较指定字节数组，采用Bytes.compareTo(byte[]) BinaryPrefixComparator 跟前面相同，只是比较左端的数据是否相同 NullComparator 判断给定的是否为空 BitComparator 按位比较 a BitwiseOp class 做异或，与，并操作 RegexStringComparator 提供一个正则的比较器，仅支持 EQUAL 和非EQUAL SubstringComparator 判断提供的子串是否出现在table的value中。
Hbase的过滤器分类
1.比较过滤器 Comparison Filters
1.1 RowFilter
构造函数：
public RowFilter(org.apache.hadoop.hbase.filter.CompareFilter.CompareOp rowCompareOp, org.apache.hadoop.hbase.filter.WritableByteArrayComparable rowComparator) {}
//选择比较RowKey来确认返回讯息示例代码：
public class RowFilterExample {
public static void main(String[] args) throws IOException {
Configuration conf = HBaseConfiguration.create();
HBaseHelper helper = HBaseHelper.getHelper(conf);
helper.dropTable("testtable");
helper.createTable("testtable", "colfam1", "colfam2");
System.out.println("Adding rows to table...");
helper.fillTable("testtable", 1, 100, 100, "colfam1", "colfam2");
HTable table = new HTable(conf, "testtable");
// vv RowFilterExample
Scan scan = new Scan();
scan.addColumn(Bytes.toBytes("colfam1"), Bytes.toBytes("col-0"));
Filter filter1 = new RowFilter(CompareFilter.CompareOp.LESS_OR_EQUAL, // co RowFilterExample-1-Filter1 Create filter, while specifying the comparison operator and comparator. Here an exact match is needed.
new BinaryComparator(Bytes.toBytes("row-22")));
scan.setFilter(filter1);
ResultScanner scanner1 = table.getScanner(scan);
// ^^ RowFilterExample
System.out.println("Scanning table #1...");
// vv RowFilterExample
for (Result res : scanner1) {
System.out.println(res);
}
scanner1.close();
Filter filter2 = new RowFilter(CompareFilter.CompareOp.EQUAL, // co RowFilterExample-2-Filter2 Another filter, this time using a regular expression to match the row keys.
new RegexStringComparator(".*-.5"));
scan.setFilter(filter2);
ResultScanner scanner2 = table.getScanner(scan);
// ^^ RowFilterExample
System.out.println("Scanning table #2...");
// vv RowFilterExample
for (Result res : scanner2) {
System.out.println(res);
}
scanner2.close();
Filter filter3 = new RowFilter(CompareFilter.CompareOp.EQUAL, // co RowFilterExample-3-Filter3 The third filter uses a substring match approach.
new SubstringComparator("-5"));
scan.setFilter(filter3);
ResultScanner scanner3 = table.getScanner(scan);
// ^^ RowFilterExample
System.out.println("Scanning table #3...");
// vv RowFilterExample
for (Result res : scanner3) {
System.out.println(res);
}
scanner3.close();
// ^^ RowFilterExample
}
}1.2 FamilyFilter
构造函数
public FamilyFilter(CompareOp familyCompareOp, WritableByteArrayComparable familyComparator) {}1
示例代码
//通过对比FamilyKey去获取数据public class FamilyFilterExample {
public static void main(String[] args) throws IOException {
Configuration conf = HBaseConfiguration.create();
HBaseHelper helper = HBaseHelper.getHelper(conf);
helper.dropTable("testtable");
helper.createTable("testtable", "colfam1", "colfam2", "colfam3", "colfam4");
System.out.println("Adding rows to table...");
helper.fillTable("testtable", 1, 10, 2, "colfam1", "colfam2", "colfam3", "colfam4");
HTable table = new HTable(conf, "testtable");
// vv FamilyFilterExample
Filter filter1 = new FamilyFilter(CompareFilter.CompareOp.LESS, // co FamilyFilterExample-1-Filter Create filter, while specifying the comparison operator and comparator.
new BinaryComparator(Bytes.toBytes("colfam3")));
Scan scan = new Scan();
scan.setFilter(filter1);
ResultScanner scanner = table.getScanner(scan); // co FamilyFilterExample-2-Scan Scan over table while applying the filter.
// ^^ FamilyFilterExample
System.out.println("Scanning table... ");
// vv FamilyFilterExample
for (Result result : scanner) {
System.out.println(result);
}
scanner.close();
Get get1 = new Get(Bytes.toBytes("row-5"));
get1.setFilter(filter1);
Result result1 = table.get(get1); // co FamilyFilterExample-3-Get Get a row while applying the same filter.
System.out.println("Result of get(): " + result1);
Filter filter2 = new FamilyFilter(CompareFilter.CompareOp.EQUAL,
new BinaryComparator(Bytes.toBytes("colfam3")));
Get get2 = new Get(Bytes.toBytes("row-5")); // co FamilyFilterExample-4-Mismatch Create a filter on one column family while trying to retrieve another.
get2.addFamily(Bytes.toBytes("colfam1"));
get2.setFilter(filter2);
Result result2 = table.get(get2); // co FamilyFilterExample-5-Get2 Get the same row while applying the new filter, this will return "NONE".
System.out.println("Result of get(): " + result2);
// ^^ FamilyFilterExample
}
}1.3QualifierFilter
构造函数
public QualifierFilter(CompareOp qualifierCompareOp, WritableByteArrayComparable qualifierComparator) { }示例代码：
//通过和列名比较，返回为真的数据// vv QualifierFilterExample
Filter filter = new QualifierFilter(CompareFilter.CompareOp.LESS_OR_EQUAL,
new BinaryComparator(Bytes.toBytes("col-2")));
Scan scan = new Scan();
scan.setFilter(filter);
ResultScanner scanner = table.getScanner(scan);
// ^^ QualifierFilterExample
System.out.println("Scanning table... ");
// vv QualifierFilterExample
for (Result result : scanner) {
System.out.println(result);
}
scanner.close();
Get get = new Get(Bytes.toBytes("row-5"));
get.setFilter(filter);
Result result = table.get(get);
System.out.println("Result of get(): " + result);1.4 ValueFliter
public ValueFilter(CompareOp valueCompareOp, WritableByteArrayComparable valueComparator) { }//对比列值获取返回数据
Filter filter = new ValueFilter(CompareFilter.CompareOp.EQUAL, // co ValueFilterExample-1-Filter Create filter, while specifying the comparison operator and comparator.
new SubstringComparator(".4") );
Scan scan = new Scan();
scan.setFilter(filter); // co ValueFilterExample-2-SetFilter Set filter for the scan.
ResultScanner scanner = table.getScanner(scan);
// ^^ ValueFilterExample
System.out.println("Results of scan:");
// vv ValueFilterExample
for (Result result : scanner) {
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " + // co ValueFilterExample-3-Print1 Print out value to check that filter works.
Bytes.toString(kv.getValue()));
}
}
scanner.close();
Get get = new Get(Bytes.toBytes("row-5"));
get.setFilter(filter); // co ValueFilterExample-4-SetFilter2 Assign same filter to Get instance.
Result result = table.get(get);
// ^^ ValueFilterExample
System.out.println("Result of get: ");
// vv ValueFilterExample
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
}1.5 DependentColumnFilter
该过滤器有两个参数 —— 列族和列修饰。 尝试找到该列所在的每一行，并返回该行具有相同时间戳的全部键值对。如果某一行不包含指定的列，则该行的任何键值对都不返回。 该过滤器还可以有一个可选布尔参数 —— dropDependentColumn. 如果为true, 从属的列不返回。 该过滤器还可以有两个可选参数 —— 一个比较操作符和一个值比较器，用于列族和修饰的进一步检查。如果从属的列找到，其值还必须通过值检查，然后就是时间戳必须考虑。
示例代码
package filters; // cc DependentColumnFilterExample Example using a filter to include only specific column families
import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hbase.HBaseConfiguration; import org.apache.hadoop.hbase.KeyValue; import org.apache.hadoop.hbase.client.Get; import org.apache.hadoop.hbase.client.HTable; import org.apache.hadoop.hbase.client.Result; import org.apache.hadoop.hbase.client.ResultScanner; import org.apache.hadoop.hbase.client.Scan; import org.apache.hadoop.hbase.filter.BinaryPrefixComparator; import org.apache.hadoop.hbase.filter.CompareFilter; import org.apache.hadoop.hbase.filter.DependentColumnFilter; import org.apache.hadoop.hbase.filter.Filter; import org.apache.hadoop.hbase.filter.RegexStringComparator; import org.apache.hadoop.hbase.filter.WritableByteArrayComparable; import org.apache.hadoop.hbase.util.Bytes; import util.HBaseHelper; import java.io.IOException; public class DependentColumnFilterExample {
private static HTable table = null;
// vv DependentColumnFilterExample
private static void filter(boolean drop,
CompareFilter.CompareOp operator,
WritableByteArrayComparable comparator)
throws IOException {
Filter filter;
if (comparator != null) {
filter = new DependentColumnFilter(Bytes.toBytes("colfam1"), // co DependentColumnFilterExample-1-CreateFilter Create the filter with various options.
Bytes.toBytes("col-5"), drop, operator, comparator);
} else {
filter = new DependentColumnFilter(Bytes.toBytes("colfam1"),
Bytes.toBytes("col-5"), drop);
}
Scan scan = new Scan();
scan.setFilter(filter);
ResultScanner scanner = table.getScanner(scan);
// ^^ DependentColumnFilterExample
System.out.println("Results of scan:");
// vv DependentColumnFilterExample
for (Result result : scanner) {
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
}
}
scanner.close();
Get get = new Get(Bytes.toBytes("row-5"));
get.setFilter(filter);
Result result = table.get(get);
// ^^ DependentColumnFilterExample
System.out.println("Result of get: ");
// vv DependentColumnFilterExample
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
}
// ^^ DependentColumnFilterExample
System.out.println("");
// vv DependentColumnFilterExample
}
public static void main(String[] args) throws IOException {
// ^^ DependentColumnFilterExample
Configuration conf = HBaseConfiguration.create();
HBaseHelper helper = HBaseHelper.getHelper(conf);
helper.dropTable("testtable");
helper.createTable("testtable", "colfam1", "colfam2");
System.out.println("Adding rows to table...");
helper.fillTable("testtable", 1, 10, 10, true, "colfam1", "colfam2");
table = new HTable(conf, "testtable");
// vv DependentColumnFilterExample
filter(true, CompareFilter.CompareOp.NO_OP, null);
filter(false, CompareFilter.CompareOp.NO_OP, null); // co DependentColumnFilterExample-2-Filter Call filter method with various options.
filter(true, CompareFilter.CompareOp.EQUAL,
new BinaryPrefixComparator(Bytes.toBytes("val-5")));
filter(false, CompareFilter.CompareOp.EQUAL,
new BinaryPrefixComparator(Bytes.toBytes("val-5")));
filter(true, CompareFilter.CompareOp.EQUAL,
new RegexStringComparator(".*\\.5"));
filter(false, CompareFilter.CompareOp.EQUAL,
new RegexStringComparator(".*\\.5"));
}
// ^^ DependentColumnFilterExample}2. Dedicated Filter
2.1 SingleColumValueFilter
//选定列簇和某一列，然后与列的value相比，正确的返回全部的row，注意如果某一行不含有该列，同样返回，除非通过filterIfColumnMissing 设置成真。//第一个构造函数相当于构建了一个BinaryComparator的实例。其他的跟CompareFilter的参数含义一样。 SingleColumnValueFilter(byte[] family, byte[] qualifier, CompareOp compareOp, byte[] value){}
SingleColumnValueFilter(byte[] family, byte[] qualifier, CompareOp compareOp, WritableByteArrayComparable comparator){ }//第一个构造函数相当于构建了一个BinaryComparator的实例。其他的跟CompareFilter的参数含义一样。 boolean getFilterIfMissing()
void setFilterIfMissing(boolean filterIfMissing)
boolean getLatestVersionOnly()
void setLatestVersionOnly(boolean latestVersionOnly)
//如果 filterIfColumnMissing 标志设为真，如果该行没有指定的列，那么该行的所有列将不发出。缺省值为假。//如果 setLatestVersionOnly 标志设为假，将检查此前的版本。缺省值为真。实例如下：// vv SingleColumnValueFilterExample
SingleColumnValueFilter filter = new SingleColumnValueFilter(
Bytes.toBytes("colfam1"),
Bytes.toBytes("col-5"),
CompareFilter.CompareOp.NOT_EQUAL,
new SubstringComparator("val-5"));
filter.setFilterIfMissing(true);
Scan scan = new Scan();
scan.setFilter(filter);
ResultScanner scanner = table.getScanner(scan);
// ^^ SingleColumnValueFilterExample
System.out.println("Results of scan:");
// vv SingleColumnValueFilterExample
for (Result result : scanner) {
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
}
}
scanner.close();
Get get = new Get(Bytes.toBytes("row-6"));
get.setFilter(filter);
Result result = table.get(get);
System.out.println("Result of get: ");
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
}2.2 SingleColumnValueExcludeFilter
与SingleColumnValueFilter相反，与条件相符的将不会返回
2.2 PrefixFilter
所有的row的实例匹配prefix的时候返回结果集合
Filter filter = new PrefixFilter(Bytes.toBytes("row1"));
Scan scan = new Scan();
scan.setFilter(filter);
ResultScanner scanner = table.getScanner(scan);
for(Result result: scanner){
for(KeyValue kv: result.raw()) {
System.out.println("KV:" + kv + ", Value:" + Bytes.toString(kv.getValue()));
}
}
scanner.close();
Get get = new Get(Bytes.toBytes("row-5"));
get.setFilter(filter);
Result result = table.get(get);
for(KeyValue kv : result.raw()){
System.out.println("KV:" + kv + ", Value:" + Bytes.toString(kv.getValue()));
}2.4 PageFilter
//页过滤
//通过设置pagesize可以设置返回每一页的page大小
//客户端需要记录上一次返回的row的Key值
package hbaseTest; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hbase.HBaseConfiguration; import org.apache.hadoop.hbase.client.HTable; import org.apache.hadoop.hbase.client.Result; import org.apache.hadoop.hbase.client.ResultScanner; import org.apache.hadoop.hbase.client.Scan; import org.apache.hadoop.hbase.filter.Filter; import org.apache.hadoop.hbase.filter.PageFilter; import org.apache.hadoop.hbase.util.Bytes; import java.io.IOException; /**
* Hello world!
*/ public class PageFilterExample {
public static void main(String[] args) throws IOException {
Configuration config = HBaseConfiguration.create();
config.set("hbase.zookeeper.quorum", "QT-H-0038");
String tableName = "testTable";
String cfName = "colfam1";
final byte[] POSTFIX = new byte[] { 0x00 };
HTable table = new HTable(config, tableName);
Filter filter = new PageFilter(15);
byte[] lastRow = null;
int totalRows = 0;
while (true) {
Scan scan = new Scan();
scan.setFilter(filter);
if(lastRow != null){
//注意这里添加了POSTFIX操作，不然死循环了
byte[] startRow = Bytes.add(lastRow,POSTFIX);
scan.setStartRow(startRow);
}
ResultScanner scanner = table.getScanner(scan);
int localRows = 0;
Result result;
while((result = scanner.next()) != null){
System.out.println(localRows++ + ":" + result);
totalRows ++;
lastRow = result.getRow();
}
scanner.close();
if(localRows == 0) break;
}
System.out.println("total rows:" + totalRows);
}
}
//因为hbase的row是字典序列排列的，因此上一次的lastrow需要添加额外的0(0x00)表示新的开始。另外startKey的那一行是包含在scan里面的。
// final byte[] POSTFIX = new byte[] { 0x00 };2.5 KeyOnlyFilter
因为一些应用只想获取data数据，而不是真实的val，可以使用这个过滤器。该过滤器通过
KeyOnlyFilter(boolean lenAsVal) //lenAsVal默认为假，表示不把val的长度作为val。否则 val的长度将作为val输出。
final byte[] POSTFIX = new byte[] { 0x00 };
HTable table = new HTable(config, tableName);
Filter filter = new KeyOnlyFilter(false);
byte[] lastRow = null;
int totalRows = 0;
Scan scan = new Scan();
scan.setFilter(filter);
ResultScanner scanner = table.getScanner(scan);
for(Result result: scanner){
for(KeyValue kv: result.raw()){
System.out.println(kv + ":" + Bytes.toString(kv.getValue()));
}
}2.6 FirstKeyOnlyFilter
//在对hbase的表进行扫描的时候，如果指定了FirstKeyOnlyFilter过滤条件则仅仅会返回相同key的第一条kv。//当对hbase中的表进行count，sum操作等集合操作的时候，使用FirstKeyOnlyFilter会带来性能上的提升。public class KeyOnlyFilterExample {
public static void main(String[] args) throws IOException {
Configuration config = HBaseConfiguration.create();
config.set("hbase.zookeeper.quorum", "QT-H-0038");
String tableName = "testTable";
String cfName = "colfam1";
final byte[] POSTFIX = new byte[] { 0x00 };
HTable table = new HTable(config, tableName);
Filter filter = new FirstKeyOnlyFilter();
byte[] lastRow = null;
int totalRows = 0;
Scan scan = new Scan();
scan.setFilter(filter);
ResultScanner scanner = table.getScanner(scan);
for(Result result: scanner){
for(KeyValue kv: result.raw()){
System.out.println(kv + ":" + Bytes.toString(kv.getValue()));
}
}
}
}返回的结果是 row-5/colfam1:qual1/1354673733503/Put/vlen=4:row1 row1/colfam1:qual1/1354432930568/Put/vlen=4:val1 row2/colfam1:qual2/1354432930568/Put/vlen=4:val3 如果注释掉过滤器的返回的结果是： row-5/colfam1:qual1/1354673733503/Put/vlen=4:row1 row1/colfam1:qual1/1354432930568/Put/vlen=4:val1 row1/colfam1:qual2/1354435819120/Put/vlen=4:val2 row2/colfam1:qual2/1354432930568/Put/vlen=4:val3
2.7 InclusiveStopFilter
//因为hbase的scan包含start-row不包含stop-row 如果使用这个过滤器我们可以包含stop-row
HTable table = new HTable(config, tableName);
Filter filter = new InclusiveStopFilter(Bytes.toBytes("row1"));
Scan scan = new Scan();
scan.setFilter(filter);
scan.setStartRow(Bytes.toBytes("row-5"));
ResultScanner scanner = table.getScanner(scan);
for(Result result: scanner){
System.out.println(result);
}
//会看到row1包含在结果中了。2.8 TimestampsFilter
当访问某个Timestamp的新闻的时候，我们需要如下的代码：
TimestampsFilter(List<Long> timestamps)
接受的参数的list参数，该Filter也可以和scan.setTimeRange混合使用。例如：// vv TimestampFilterExample
List<Long> ts = new ArrayList<Long>();
ts.add(new Long(5));
ts.add(new Long(10)); // co TimestampFilterExample-1-AddTS Add timestamps to the list.
ts.add(new Long(15));
Filter filter = new TimestampsFilter(ts);
Scan scan1 = new Scan();
scan1.setFilter(filter); // co TimestampFilterExample-2-AddFilter Add the filter to an otherwise default Scan instance.
ResultScanner scanner1 = table.getScanner(scan1);
// ^^ TimestampFilterExample
System.out.println("Results of scan #1:");
// vv TimestampFilterExample
for (Result result : scanner1) {
System.out.println(result);
}
scanner1.close();
Scan scan2 = new Scan();
scan2.setFilter(filter);
scan2.setTimeRange(8, 12); // co TimestampFilterExample-3-AddTSRange Also add a time range to verify how it affects the filter
ResultScanner scanner2 = table.getScanner(scan2);
// ^^ TimestampFilterExample
System.out.println("Results of scan #2:");
// vv TimestampFilterExample
for (Result result : scanner2) {
System.out.println(result);
}
scanner2.close();2.9 ColumnCountGetFilter
//在scan时是无用的
2.10 ColumnPaginationFilter（下来用到的时候在仔细研究下）
/**
* A filter, based on the ColumnCountGetFilter, takes two arguments: limit and offset.
* This filter can be used for row-based indexing, where references to other tables are stored across many columns,
* in order to efficient lookups and paginated results for end users.
*/Filter filter = new ColumnPaginationFilter(5, 15);
Scan scan = new Scan();
scan.setFilter(filter);
ResultScanner scanner = table.getScanner(scan);
// ^^ ColumnPaginationFilterExample
System.out.println("Results of scan:");
// vv ColumnPaginationFilterExample
for (Result result : scanner) {
System.out.println(result);
}
scanner.close();2.11 ColumnPrefixFilter
// 跟prefxiFilter相似，只是改成了Column，实例如下：// vv ColumnPaginationFilterExample
Filter filter = new ColumnPrefixFilter(Bytes.toBytes("qual2"));
Scan scan = new Scan();
scan.setFilter(filter);
ResultScanner scanner = table.getScanner(scan);
// ^^ ColumnPaginationFilterExample
System.out.println("Results of scan:");
// vv ColumnPaginationFilterExample
for (Result result : scanner) {
System.out.println(result);
}
scanner.close();
// 值scan到与列值与前面匹配的数据。例如qual2匹配qual21。2.12 RandomRowFilter
// 随即的返回row的数据，构造函数为RandomRowFilter(float chance) // chance取值为0到1.0，如果<0则为空，如果>1则包含所有的行。
3. Decorating Filters
3.1 SkipFilter
//这个过滤器只作用到keyValueFilter上。KeyValueFilter会返回所有满足条件的row及对应的列。而加上SkipFilter以后。会发现如果某一行的某一列不符合条件，则这一行全部不返回了。public static void main(String[] args) throws IOException {
Configuration conf = HBaseConfiguration.create();
HBaseHelper helper = HBaseHelper.getHelper(conf);
helper.dropTable("testtable");
helper.createTable("testtable", "colfam1");
System.out.println("Adding rows to table...");
helper.fillTable("testtable", 1, 30, 5, 2, true, true, "colfam1");
HTable table = new HTable(conf, "testtable");
// vv SkipFilterExample
Filter filter1 = new ValueFilter(CompareFilter.CompareOp.NOT_EQUAL,
new BinaryComparator(Bytes.toBytes("val-0")));
Scan scan = new Scan();
scan.setFilter(filter1); // co SkipFilterExample-1-AddFilter1 Only add the ValueFilter to the first scan.
ResultScanner scanner1 = table.getScanner(scan);
// ^^ SkipFilterExample
System.out.println("Results of scan #1:");
int n = 0;
// vv SkipFilterExample
for (Result result : scanner1) {
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
// ^^ SkipFilterExample
n++;
// vv SkipFilterExample
}
}
scanner1.close();
Filter filter2 = new SkipFilter(filter1);
scan.setFilter(filter2); // co SkipFilterExample-2-AddFilter2 Add the decorating skip filter for the second scan.
ResultScanner scanner2 = table.getScanner(scan);
// ^^ SkipFilterExample
System.out.println("Total KeyValue count for scan #1: " + n);
n = 0;
System.out.println("Results of scan #2:");
// vv SkipFilterExample
for (Result result : scanner2) {
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
// ^^ SkipFilterExample
n++;
// vv SkipFilterExample
}
}
scanner2.close();
// ^^ SkipFilterExample
System.out.println("Total KeyValue count for scan #2: " + n);
}3.2 WhileMatchFilters
相当于while执行，知道不match就break了返回了。
随时随地看视频
