Hbase filter

第一个例子是RowFilter的

Scan scan = new Scan();scan.addColumn(Bytes.toBytes("colfam1"),Bytes.toBytes("col-0"));Filter filter1 = new RowFilter(CompareFilter.CompareOp.LESS_OR_EQUAL,                                               new BinaryComparator(Bytes.toBytes("row-22")));scan.setFilter(filter1);ResultScanner scanner1 = table.getScanner(scan);for (Result res : scanner1) {    System.out.println(res);}scanner1.close();Filter filter2 = new RowFilter(CompareFilter.CompareOp.EQUAL,                                              new RegexStringComparator(".*-.5"));scan.setFilter(filter2);ResultScanner scanner2 = table.getScanner(scan);for (Result res : scanner2) {     System.out.println(res);}scanner2.close();Filter filter3 = new RowFilter(CompareFilter.CompareOp.EQUAL,                                               new SubstringComparator("-5"));scan.setFilter(filter3);ResultScanner scanner3 = table.getScanner(scan);for (Result res : scanner3) {      System.out.println(res);}scanner3.close();

第二个例子是QualifierFilter的

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);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);

第三个例子是ValueFilter

Filter filter = new ValueFilter(CompareFilter.CompareOp.EQUAL,                                                new SubstringComparator(".4"));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()));}

第四个例子是PageFilter，分页的filter

Filter filter = new PageFilter(15);int totalRows = 0;byte[] lastRow = null;while (true) {    Scan scan = new Scan();    scan.setFilter(filter);    if (lastRow != null) {         byte[] startRow = Bytes.add(lastRow, POSTFIX);        System.out.println("start row: " +Bytes.toStringBinary(startRow));         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);

第五个例子是InclusiveStopFilter，它是什么意思呢，就是扫描到某个rowkey就停止，下面的例子是从row-3开始扫描，一直扫描到row-5结束。

Filter filter = newInclusiveStopFilter(Bytes.toBytes("row-5"));Scan scan = new Scan();scan.setStartRow(Bytes.toBytes("row-3"));scan.setFilter(filter);ResultScanner scanner = table.getScanner(scan);    for (Result result : scanner) {    System.out.println(result);}scanner.close();

第六个SingleColumnValueFilter，这个是我们最常用的filter，我觉得很好用。

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);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()));}

第七个FilterList，它有两个选项，需要全部通过，还是一个通过就行，MUST_PASS_ALL，MUST_PASS_ONE。

List<Filter> filters = new ArrayList<Filter>();Filter filter1 = newRowFilter(CompareFilter.CompareOp.GREATER_OR_EQUAL,new BinaryComparator(Bytes.toBytes("row-03")));filters.add(filter1);Filter filter2 = newRowFilter(CompareFilter.CompareOp.LESS_OR_EQUAL,new BinaryComparator(Bytes.toBytes("row-06")));filters.add(filter2);Filter filter3 = newQualifierFilter(CompareFilter.CompareOp.EQUAL,new RegexStringComparator("col-0[03]"));filters.add(filter3);FilterList filterList1 = new FilterList(filters);Scan scan = new Scan();scan.setFilter(filterList1);ResultScanner scanner1 = table.getScanner(scan);for (Result result : scanner1) {for (KeyValue kv : result.raw()) {    System.out.println("KV: " + kv + ", Value: " +    Bytes.toString(kv.getValue()));    }}scanner1.close();FilterList filterList2 = new FilterList(FilterList.Operator.MUST_PASS_ONE, filters);scan.setFilter(filterList2);ResultScanner scanner2 = table.getScanner(scan); for (Result result : scanner2) {     for (KeyValue kv : result.raw()) {    System.out.println("KV: " + kv + ", Value: " +    Bytes.toString(kv.getValue()));    }}scanner2.close();

这里要讲的是自定义filter，从FilterBase继承

public class CustomFilter extends FilterBase {    private byte[] value = null;    private boolean filterRow = true;    public CustomFilter() {        super();    }    public CustomFilter(byte[] value) {        this.value = value;    }    @Override    public void reset() {        this.filterRow = true;    }    @Override    public ReturnCode filterKeyValue(KeyValue kv) {        if (Bytes.compareTo(value, kv.getValue()) == 0) {            filterRow = false;        }        return ReturnCode.INCLUDE;    }    @Override    public boolean filterRow() {        return filterRow;    }    @Override    public void write(DataOutput dataOutput) throws IOException {        Bytes.writeByteArray(dataOutput, this.value);    }    @Override    public void readFields(DataInput dataInput) throws IOException {        this.value = Bytes.readByteArray(dataInput);    }}

然后打成jar包，要在hbase-env.sh中指明路径。

export  HBASE_CLASSPATH="/hbase/target/hbase-customfilter.jar"，然后就可以在客户端中使用它了。

转自http://www.cnblogs.com/cenyuhai/p/3231369.html