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From ehatc...@apache.org
Subject cvs commit: jakarta-lucene/src/test/org/apache/lucene/document TestNumberTools.java
Date Tue, 23 Nov 2004 21:07:51 GMT
ehatcher    2004/11/23 13:07:49

  Modified:    .        CHANGES.txt
  Added:       src/java/org/apache/lucene/document NumberTools.java
               src/test/org/apache/lucene/document TestNumberTools.java
  Log:
  Add first pass for NumberUtils, adapted from code contributed by Matt Quail.
  
  Revision  Changes    Path
  1.126     +6 -2      jakarta-lucene/CHANGES.txt
  
  Index: CHANGES.txt
  ===================================================================
  RCS file: /home/cvs/jakarta-lucene/CHANGES.txt,v
  retrieving revision 1.125
  retrieving revision 1.126
  diff -u -r1.125 -r1.126
  --- CHANGES.txt	23 Nov 2004 14:17:18 -0000	1.125
  +++ CHANGES.txt	23 Nov 2004 21:07:48 -0000	1.126
  @@ -48,7 +48,11 @@
    9. Added javadocs-internal to build.xml - bug #30360
       (Paul Elschot via Otis)
       
  -10. Added RangeFilter. (Chris M Hostetter via Erik)
  +10. Added RangeFilter, a more generically useful filter than DateFilter.
  +    (Chris M Hostetter via Erik)
  +
  +11. Added NumberTools, a utility class indexing numeric fields.
  +    (adapted from code contributed by Matt Quail; committed by Erik)
   
   API Changes
   
  
  
  
  1.1                  jakarta-lucene/src/java/org/apache/lucene/document/NumberTools.java
  
  Index: NumberTools.java
  ===================================================================
  package org.apache.lucene.document;
  
  /**
   * Copyright 2004 The Apache Software Foundation
   *
   * Licensed 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
   * limitations under the License.
   */
  
  
  /**
   * Provides support for converting longs to Strings, and back again. The strings
   * are structured so that lexicographic sorting order is preserved.
   * 
   * <p>
   * That is, if l1 is less than l2 for any two longs l1 and l2, then
   * LongField.longToString(l1) is lexicographically less than
   * LongField.longToString(l2). (Similarly for "greater than" and "equals".)
   * 
   * <p>
   * This class handles <b>all</b> long values (unlike
   * {@link org.apache.lucene.document.DateField}).
   * 
   * @author Matt Quail (spud at madbean dot com)
   */
  public class NumberTools {
  
      private static final int RADIX = 36;
  
      private static final char NEGATIVE_PREFIX = '-';
  
      // NB: NEGATIVE_PREFIX must be < POSITIVE_PREFIX
      private static final char POSITIVE_PREFIX = '0';
  
      //NB: this must be less than
      /**
       * Equivalent to longToString(Long.MIN_VALUE)
       */
      public static final String MIN_STRING_VALUE = NEGATIVE_PREFIX
              + "0000000000000";
  
      /**
       * Equivalent to longToString(Long.MAX_VALUE)
       */
      public static final String MAX_STRING_VALUE = POSITIVE_PREFIX
              + "1y2p0ij32e8e7";
  
      /**
       * the length of (all) strings returned by {@link #longToString}
       */
      public static final int STR_SIZE = MIN_STRING_VALUE.length();
  
      /**
       * Converts a long to a String suitable for indexing.
       */
      public static String longToString(long l) {
  
          if (l == Long.MIN_VALUE) {
              // special case, because long is not symetric around zero
              return MIN_STRING_VALUE;
          }
  
          StringBuffer buf = new StringBuffer(STR_SIZE);
  
          if (l < 0) {
              buf.append(NEGATIVE_PREFIX);
              l = Long.MAX_VALUE + l + 1;
          } else {
              buf.append(POSITIVE_PREFIX);
          }
          String num = Long.toString(l, RADIX);
  
          int padLen = STR_SIZE - num.length() - buf.length();
          while (padLen-- > 0) {
              buf.append('0');
          }
          buf.append(num);
  
          return buf.toString();
      }
  
      /**
       * Converts a String that was returned by {@link #longToString}back to a
       * long.
       * 
       * @throws IllegalArgumentException
       *             if the input is null
       * @throws NumberFormatException
       *             if the input does not parse (it was not a String returned by
       *             longToString()).
       */
      public static long stringToLong(String str) {
          if (str == null) {
              throw new IllegalArgumentException("string cannot be null");
          }
          if (str.length() != STR_SIZE) {
              throw new NumberFormatException("string is the wrong size");
          }
  
          if (str.equals(MIN_STRING_VALUE)) {
              return Long.MIN_VALUE;
          }
  
          char prefix = str.charAt(0);
          long l = Long.parseLong(str.substring(1), RADIX);
  
          if (prefix == POSITIVE_PREFIX) {
              // nop
          } else if (prefix == NEGATIVE_PREFIX) {
              l = l - Long.MAX_VALUE - 1;
          } else {
              throw new NumberFormatException(
                      "string does not begin with the correct prefix");
          }
  
          return l;
      }
  }
  
  
  1.1                  jakarta-lucene/src/test/org/apache/lucene/document/TestNumberTools.java
  
  Index: TestNumberTools.java
  ===================================================================
  package org.apache.lucene.document;
  
  /**
   * Copyright 2004 The Apache Software Foundation
   *
   * Licensed 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
   * limitations under the License.
   */
  
  import junit.framework.TestCase;
  
  public class TestNumberTools extends TestCase {
      public void testNearZero() {
          for (int i = -100; i <= 100; i++) {
              for (int j = -100; j <= 100; j++) {
                  subtestTwoLongs(i, j);
              }
          }
      }
  
      public void testMax() {
          // make sure the constants convert to their equivelents
          assertEquals(Long.MAX_VALUE, NumberTools
                  .stringToLong(NumberTools.MAX_STRING_VALUE));
          assertEquals(NumberTools.MAX_STRING_VALUE, NumberTools
                  .longToString(Long.MAX_VALUE));
  
          // test near MAX, too
          for (long l = Long.MAX_VALUE; l > Long.MAX_VALUE - 10000; l--) {
              subtestTwoLongs(l, l - 1);
          }
      }
  
      public void testMin() {
          // make sure the constants convert to their equivelents
          assertEquals(Long.MIN_VALUE, NumberTools
                  .stringToLong(NumberTools.MIN_STRING_VALUE));
          assertEquals(NumberTools.MIN_STRING_VALUE, NumberTools
                  .longToString(Long.MIN_VALUE));
  
          // test near MIN, too
          for (long l = Long.MIN_VALUE; l < Long.MIN_VALUE + 10000; l++) {
              subtestTwoLongs(l, l + 1);
          }
      }
  
      private static void subtestTwoLongs(long i, long j) {
          // convert to strings
          String a = NumberTools.longToString(i);
          String b = NumberTools.longToString(j);
  
          // are they the right length?
          assertEquals(NumberTools.STR_SIZE, a.length());
          assertEquals(NumberTools.STR_SIZE, b.length());
  
          // are they the right order?
          if (i < j) {
              assertTrue(a.compareTo(b) < 0);
          } else if (i > j) {
              assertTrue(a.compareTo(b) > 0);
          } else {
              assertEquals(a, b);
          }
  
          // can we convert them back to longs?
          long i2 = NumberTools.stringToLong(a);
          long j2 = NumberTools.stringToLong(b);
  
          assertEquals(i, i2);
          assertEquals(j, j2);
      }
  }
  
  

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