diff --git a/src/java/org/apache/lucene/search/WildcardTermEnum.java b/src/java/org/apache/lucene/search/WildcardTermEnum.java index 778cac451f3..8ae9da7ff7f 100644 --- a/src/java/org/apache/lucene/search/WildcardTermEnum.java +++ b/src/java/org/apache/lucene/search/WildcardTermEnum.java @@ -59,10 +59,13 @@ import org.apache.lucene.index.IndexReader; import org.apache.lucene.index.Term; import org.apache.lucene.index.TermEnum; -/** Subclass of FilteredTermEnum for enumerating all terms that match the specified wildcard filter term. - -

Term enumerations are always ordered by Term.compareTo(). Each term in - the enumeration is greater than all that precede it. */ +/** + * Subclass of FilteredTermEnum for enumerating all terms that match the + * specified wildcard filter term. + *

+ * Term enumerations are always ordered by Term.compareTo(). Each term in + * the enumeration is greater than all that precede it. + */ public class WildcardTermEnum extends FilteredTermEnum { Term searchTerm; String field = ""; @@ -71,7 +74,7 @@ public class WildcardTermEnum extends FilteredTermEnum { int preLen = 0; boolean fieldMatch = false; boolean endEnum = false; - + /** Creates new WildcardTermEnum */ public WildcardTermEnum(IndexReader reader, Term term) throws IOException { super(reader, term); @@ -90,7 +93,7 @@ public class WildcardTermEnum extends FilteredTermEnum { text = text.substring(preLen); setEnum(reader.terms(new Term(searchTerm.field(), pre))); } - + final protected boolean termCompare(Term term) { if (field == term.field()) { String searchText = term.text(); @@ -101,49 +104,118 @@ public class WildcardTermEnum extends FilteredTermEnum { endEnum = true; return false; } - + final public float difference() { return 1.0f; } - + final public boolean endEnum() { return endEnum; } - + /******************************************** * String equality with support for wildcards ********************************************/ - + public static final char WILDCARD_STRING = '*'; public static final char WILDCARD_CHAR = '?'; - - public static final boolean wildcardEquals(String pattern, int patternIdx, String string, int stringIdx) { - for ( int p = patternIdx; ; ++p ) { - for ( int s = stringIdx; ; ++p, ++s ) { - boolean sEnd = (s >= string.length()); - boolean pEnd = (p >= pattern.length()); - - if (sEnd && pEnd) return true; - if (sEnd || pEnd) break; - if (pattern.charAt(p) == WILDCARD_CHAR) continue; - if (pattern.charAt(p) == WILDCARD_STRING) { - int i; - ++p; - for (i = string.length(); i >= s; --i) - if (wildcardEquals(pattern, p, string, i)) - return true; - break; - } - if (pattern.charAt(p) != string.charAt(s)) break; - } - return false; + + /** + * Determines if a word matches a wildcard pattern. + * Work released by Granta Design Ltd after originally being done on + * company time. + */ + public static final boolean wildcardEquals(String pattern, int patternIdx, + String string, int stringIdx) + { + for (int p = patternIdx; ; ++p) + { + for (int s = stringIdx; ; ++p, ++s) + { + // End of string yet? + boolean sEnd = (s >= string.length()); + // End of pattern yet? + boolean pEnd = (p >= pattern.length()); + + // If we're looking at the end of the string... + if (sEnd) + { + // Assume the only thing left on the pattern is/are wildcards + boolean justWildcardsLeft = true; + + // Current wildcard position + int wildcardSearchPos = p; + // While we haven't found the end of the pattern, + // and haven't encountered any non-wildcard characters + while (wildcardSearchPos < pattern.length() && justWildcardsLeft) + { + // Check the character at the current position + char wildchar = pattern.charAt(wildcardSearchPos); + // If it's not a wildcard character, then there is more + // pattern information after this/these wildcards. + + if (wildchar != WILDCARD_CHAR && + wildchar != WILDCARD_STRING) + { + justWildcardsLeft = false; + } + else + { + // Look at the next character + wildcardSearchPos++; + } + } + + // This was a prefix wildcard search, and we've matched, so + // return true. + if (justWildcardsLeft) + { + return true; + } + } + + // If we've gone past the end of the string, or the pattern, + // return false. + if (sEnd || pEnd) + { + break; + } + + // Match a single character, so continue. + if (pattern.charAt(p) == WILDCARD_CHAR) + { + continue; + } + + // + if (pattern.charAt(p) == WILDCARD_STRING) + { + // Look at the character beyond the '*'. + ++p; + // Examine the string, starting at the last character. + for (int i = string.length(); i >= s; --i) + { + if (wildcardEquals(pattern, p, string, i)) + { + return true; + } + } + break; + } + if (pattern.charAt(p) != string.charAt(s)) + { + break; + } + } + return false; + } + } + + public void close() throws IOException + { + super.close(); + searchTerm = null; + field = null; + text = null; } - } - - public void close() throws IOException { - super.close(); - searchTerm = null; - field = null; - text = null; - } }