Java 类org.apache.hadoop.hbase.filter.MultipleColumnPrefixFilter 实例源码

@Override
public RowFilter adapt(
    FilterAdapterContext context,
    MultipleColumnPrefixFilter filter) throws IOException {
  Interleave.Builder interleaveBuilder = Interleave.newBuilder();
  ByteArrayOutputStream outputStream = null;
  for (byte[] prefix : filter.getPrefix()) {
    if (outputStream == null) {
      outputStream = new ByteArrayOutputStream(prefix.length * 2);
    }
    outputStream.reset();

    readerExpressionHelper.writeQuotedExpression(prefix, outputStream);
    outputStream.write(ReaderExpressionHelper.ALL_QUALIFIERS_BYTES);

    RowFilter.Builder singlePrefixBuilder = RowFilter.newBuilder();
    singlePrefixBuilder.setColumnQualifierRegexFilter(
        ByteString.copyFrom(
            outputStream.toByteArray()));

    interleaveBuilder.addFilters(singlePrefixBuilder);
  }
  return RowFilter.newBuilder()
      .setInterleave(interleaveBuilder)
      .build();
}

@Test
public void multiplePrefixesAreAdapted() throws IOException {
  // Return all columns in all families that are prefixed by "prefix" or prefix2.
  MultipleColumnPrefixFilter filter =
      new MultipleColumnPrefixFilter(
          new byte[][]{Bytes.toBytes("prefix"), Bytes.toBytes("prefix2")});

  RowFilter rowFilter = filterAdapter.adapt(emptyScanContext, filter);
  Interleave interleave = rowFilter.getInterleave();
  Assert.assertEquals(2, interleave.getFiltersCount());
  Assert.assertEquals(
      "prefix\\C*",
      interleave.getFilters(0).getColumnQualifierRegexFilter().toStringUtf8());
  Assert.assertEquals(
      "prefix2\\C*",
      interleave.getFilters(1).getColumnQualifierRegexFilter().toStringUtf8());
}

/**
 * 获取这个列名过滤的column
 * 
 * @param columns
 * @return
 */
private Filter getColumnFilter(String[] columns) {
    int length = columns.length;
    byte[][] filter = new byte[length][];
    for (int i = 0; i < length; i++) {
        filter[i] = Bytes.toBytes(columns[i]);
    }
    return new MultipleColumnPrefixFilter(filter);
}

@Test
public void testMultipleColumnPrefixes() throws IOException {
  // Initialize
  String goodValue = "includeThisValue";
  Table table = getConnection().getTable(TABLE_NAME);
  byte[] rowKey = dataHelper.randomData("testRow-");
  Put put = new Put(rowKey);
  put.addColumn(COLUMN_FAMILY, dataHelper.randomData("a-"), Bytes.toBytes(goodValue));
  put.addColumn(COLUMN_FAMILY, dataHelper.randomData("b-"), Bytes.toBytes(goodValue));
  put.addColumn(COLUMN_FAMILY, dataHelper.randomData("c-"), Bytes.toBytes(goodValue));
  put.addColumn(COLUMN_FAMILY, dataHelper.randomData("d-"), Bytes.toBytes(goodValue));
  table.put(put);

  // Filter for results
  Filter filter = new MultipleColumnPrefixFilter(new byte[][]{
      Bytes.toBytes("a-"),
      Bytes.toBytes("b-")
  });

  Get get = new Get(rowKey).setFilter(filter);
  Result result = table.get(get);
  Cell[] cells = result.rawCells();
  Assert.assertEquals("Should have two cells, prefixes a- and b-.", 2, cells.length);
  byte[] qualifier0 = CellUtil.cloneQualifier(cells[0]);
  Assert.assertTrue("qualifier0 should start with a-",
      qualifier0[0] == 'a' && qualifier0[1] == '-');

  byte[] qualifier1 = CellUtil.cloneQualifier(cells[1]);
  Assert.assertTrue("qualifier1 should start with b-",
      qualifier1[0] == 'b' && qualifier1[1] == '-');

  table.close();
}

/**
 * 获取这个列名过滤的column
 * 
 * @param columns
 * @return
 */
private Filter getColumnFilter(String[] columns) {
    int length = columns.length;
    byte[][] filter = new byte[length][];
    for (int i = 0; i < length; i++) {
        filter[i] = Bytes.toBytes(columns[i]);
    }
    return new MultipleColumnPrefixFilter(filter);
}

private static Filter getColumnFilter(String[] columns) {
    int length = columns.length;
    byte[][] filter = new byte[length][];
    for (int i = 0; i < length; i++) {
        filter[i] = Bytes.toBytes(columns[i]);
    }
    return new MultipleColumnPrefixFilter(filter);
}

/**
 * Create a new FilterAdapter
 */
public static FilterAdapter buildAdapter() {
  FilterAdapter adapter = new FilterAdapter();
  adapter.addFilterAdapter(
      ColumnPrefixFilter.class, new ColumnPrefixFilterAdapter());
  adapter.addFilterAdapter(
      ColumnRangeFilter.class, new ColumnRangeFilterAdapter());
  adapter.addFilterAdapter(
      KeyOnlyFilter.class, new KeyOnlyFilterAdapter());
  adapter.addFilterAdapter(
      MultipleColumnPrefixFilter.class, new MultipleColumnPrefixFilterAdapter());
  adapter.addFilterAdapter(
      TimestampsFilter.class, new TimestampsFilterAdapter());
  ValueFilterAdapter valueFilterAdapter = new ValueFilterAdapter();
  adapter.addFilterAdapter(
      ValueFilter.class, valueFilterAdapter);
  SingleColumnValueFilterAdapter scvfa =
      new SingleColumnValueFilterAdapter(valueFilterAdapter);
  adapter.addFilterAdapter(
      SingleColumnValueFilter.class, scvfa);
  adapter.addFilterAdapter(
      SingleColumnValueExcludeFilter.class,
      new SingleColumnValueExcludeFilterAdapter(scvfa));
  adapter.addFilterAdapter(
      ColumnPaginationFilter.class, new ColumnPaginationFilterAdapter());
  adapter.addFilterAdapter(
      FirstKeyOnlyFilter.class, new FirstKeyOnlyFilterAdapter());
  adapter.addFilterAdapter(
      ColumnCountGetFilter.class, new ColumnCountGetFilterAdapter());
  adapter.addFilterAdapter(
      RandomRowFilter.class, new RandomRowFilterAdapter());
  adapter.addFilterAdapter(
      PrefixFilter.class, new PrefixFilterAdapter());
  adapter.addFilterAdapter(
      QualifierFilter.class, new QualifierFilterAdapter());

  // Passing the FilterAdapter in to the FilterListAdapter is a bit
  // unfortunate, but makes adapting the FilterList's subfilters simpler.
  FilterListAdapter filterListAdapter = new FilterListAdapter(adapter);
  // FilterList implements UnsupportedStatusCollector so it should
  // be used when possible (third parameter to addFilterAdapter()).
  adapter.addFilterAdapter(
      FilterList.class, filterListAdapter, filterListAdapter);

  return adapter;
}

@Override
public FilterSupportStatus isFilterSupported(
    FilterAdapterContext context,
    MultipleColumnPrefixFilter filter) {
  return FilterSupportStatus.SUPPORTED;
}