Java API example

This example shows how to use the Java API to implement several different filters.

This example is taken from the HBase unit test found in hbase-server/src/test/java/org/apache/hadoop/hbase/filter/TestSingleColumnValueFilter.java.

/**
      *
      * Licensed to the Apache Software Foundation (ASF) under one
      * or more contributor license agreements.  See the NOTICE file
      * distributed with this work for additional information
      * regarding copyright ownership.  The ASF licenses this file
      * to you under the Apache License, Version 2.0 (the
      * "License"); you may not use this file except in compliance
      * with the License.  You may obtain a copy of the License at
      *
      *     http://www.apache.org/licenses/LICENSE-2.0
      *
      * Unless required by applicable law or agreed to in writing, software
      * distributed under the License is distributed on an "AS IS" BASIS,
      * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      * See the License for the specific language governing permissions and
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      package org.apache.hadoop.hbase.filter;
      
      import static org.junit.Assert.assertFalse;
      import static org.junit.Assert.assertTrue;
      
      import java.util.regex.Pattern;
      
      import org.apache.hadoop.hbase.KeyValue;
      import org.apache.hadoop.hbase.SmallTests;
      import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
      import org.apache.hadoop.hbase.util.Bytes;
      import org.junit.Before;
      import org.junit.Test;
      import org.junit.experimental.categories.Category;
      
      /**
      * Tests the value filter
      */
      @Category(SmallTests.class)
      public class TestSingleColumnValueFilter {
      private static final byte[] ROW = Bytes.toBytes("test");
      private static final byte[] COLUMN_FAMILY = Bytes.toBytes("test");
      private static final byte [] COLUMN_QUALIFIER = Bytes.toBytes("foo");
      private static final byte[] VAL_1 = Bytes.toBytes("a");
      private static final byte[] VAL_2 = Bytes.toBytes("ab");
      private static final byte[] VAL_3 = Bytes.toBytes("abc");
      private static final byte[] VAL_4 = Bytes.toBytes("abcd");
      private static final byte[] FULLSTRING_1 =
      Bytes.toBytes("The quick brown fox jumps over the lazy dog.");
      private static final byte[] FULLSTRING_2 =
      Bytes.toBytes("The slow grey fox trips over the lazy dog.");
      private static final String QUICK_SUBSTR = "quick";
      private static final String QUICK_REGEX = ".+quick.+";
      private static final Pattern QUICK_PATTERN = Pattern.compile("QuIcK", Pattern.CASE_INSENSITIVE | Pattern.DOTALL);
      
      Filter basicFilter;
      Filter nullFilter;
      Filter substrFilter;
      Filter regexFilter;
      Filter regexPatternFilter;
      
      @Before
      public void setUp() throws Exception {
      basicFilter = basicFilterNew();
      nullFilter = nullFilterNew();
      substrFilter = substrFilterNew();
      regexFilter = regexFilterNew();
      regexPatternFilter = regexFilterNew(QUICK_PATTERN);
      }
      
      private Filter basicFilterNew() {
      return new SingleColumnValueFilter(COLUMN_FAMILY, COLUMN_QUALIFIER,
      CompareOp.GREATER_OR_EQUAL, VAL_2);
      }
      
      private Filter nullFilterNew() {
      return new SingleColumnValueFilter(COLUMN_FAMILY, COLUMN_QUALIFIER, CompareOp.NOT_EQUAL,
      new NullComparator());
      }
      
      private Filter substrFilterNew() {
      return new SingleColumnValueFilter(COLUMN_FAMILY, COLUMN_QUALIFIER,
      CompareOp.EQUAL,
      new SubstringComparator(QUICK_SUBSTR));
      }
      
      private Filter regexFilterNew() {
      return new SingleColumnValueFilter(COLUMN_FAMILY, COLUMN_QUALIFIER,
      CompareOp.EQUAL,
      new RegexStringComparator(QUICK_REGEX));
      }
      
      private Filter regexFilterNew(Pattern pattern) {
      return new SingleColumnValueFilter(COLUMN_FAMILY, COLUMN_QUALIFIER,
      CompareOp.EQUAL,
      new RegexStringComparator(pattern.pattern(), pattern.flags()));
      }
      
      private void basicFilterTests(SingleColumnValueFilter filter)
      throws Exception {
      KeyValue kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER, VAL_2);
      assertTrue("basicFilter1", filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER, VAL_3);
      assertTrue("basicFilter2", filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER, VAL_4);
      assertTrue("basicFilter3", filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      assertFalse("basicFilterNotNull", filter.filterRow());
      filter.reset();
      kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER, VAL_1);
      assertTrue("basicFilter4", filter.filterKeyValue(kv) == Filter.ReturnCode.NEXT_ROW);
      kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER, VAL_2);
      assertTrue("basicFilter4", filter.filterKeyValue(kv) == Filter.ReturnCode.NEXT_ROW);
      assertFalse("basicFilterAllRemaining", filter.filterAllRemaining());
      assertTrue("basicFilterNotNull", filter.filterRow());
      filter.reset();
      filter.setLatestVersionOnly(false);
      kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER, VAL_1);
      assertTrue("basicFilter5", filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER, VAL_2);
      assertTrue("basicFilter5", filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      assertFalse("basicFilterNotNull", filter.filterRow());
      }
      
      private void nullFilterTests(Filter filter) throws Exception {
      ((SingleColumnValueFilter) filter).setFilterIfMissing(true);
      KeyValue kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER, FULLSTRING_1);
      assertTrue("null1", filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      assertFalse("null1FilterRow", filter.filterRow());
      filter.reset();
      kv = new KeyValue(ROW, COLUMN_FAMILY, Bytes.toBytes("qual2"), FULLSTRING_2);
      assertTrue("null2", filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      assertTrue("null2FilterRow", filter.filterRow());
      }
      
      private void substrFilterTests(Filter filter)
      throws Exception {
      KeyValue kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER,
      FULLSTRING_1);
      assertTrue("substrTrue",
      filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER,
      FULLSTRING_2);
      assertTrue("substrFalse", filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      assertFalse("substrFilterAllRemaining", filter.filterAllRemaining());
      assertFalse("substrFilterNotNull", filter.filterRow());
      }
      
      private void regexFilterTests(Filter filter)
      throws Exception {
      KeyValue kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER,
      FULLSTRING_1);
      assertTrue("regexTrue",
      filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER,
      FULLSTRING_2);
      assertTrue("regexFalse", filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      assertFalse("regexFilterAllRemaining", filter.filterAllRemaining());
      assertFalse("regexFilterNotNull", filter.filterRow());
      }
      
      private void regexPatternFilterTests(Filter filter)
      throws Exception {
      KeyValue kv = new KeyValue(ROW, COLUMN_FAMILY, COLUMN_QUALIFIER,
      FULLSTRING_1);
      assertTrue("regexTrue",
      filter.filterKeyValue(kv) == Filter.ReturnCode.INCLUDE);
      assertFalse("regexFilterAllRemaining", filter.filterAllRemaining());
      assertFalse("regexFilterNotNull", filter.filterRow());
      }
      
      private Filter serializationTest(Filter filter)
      throws Exception {
      // Decompose filter to bytes.
      byte[] buffer = filter.toByteArray();
      
      // Recompose filter.
      Filter newFilter = SingleColumnValueFilter.parseFrom(buffer);
      return newFilter;
      }
      
      /**
      * Tests identification of the stop row
      * @throws Exception
      */
      @Test
      public void testStop() throws Exception {
      basicFilterTests((SingleColumnValueFilter) basicFilter);
      nullFilterTests(nullFilter);
      substrFilterTests(substrFilter);
      regexFilterTests(regexFilter);
      regexPatternFilterTests(regexPatternFilter);
      }
      
      /**
      * Tests serialization
      * @throws Exception
      */
      @Test
      public void testSerialization() throws Exception {
      Filter newFilter = serializationTest(basicFilter);
      basicFilterTests((SingleColumnValueFilter)newFilter);
      newFilter = serializationTest(nullFilter);
      nullFilterTests(newFilter);
      newFilter = serializationTest(substrFilter);
      substrFilterTests(newFilter);
      newFilter = serializationTest(regexFilter);
      regexFilterTests(newFilter);
      newFilter = serializationTest(regexPatternFilter);
      regexPatternFilterTests(newFilter);
      }
      
      }