org.hibernate.ogm.util.parser.impl

Class LikeExpressionToRegExpConverter

java.lang.Object

org.hibernate.ogm.util.parser.impl.LikeExpressionToRegExpConverter

public class LikeExpressionToRegExpConverter
extends Object

Creates Pattern objects equivalent to given HQL/JPQL LIKE expressions. Used by LikePredicate implementations to emulate LIKE predicates via a native regexp operator.

The following rules apply for creating regular expressions:

• the _ wildcard is replaced by . (unless it is escaped)
• the % wildcard is replaced by .* (unless it is escaped)
• non-wildcard character sequences are quoted (wrapped by \\Q...\\E) to match them as is
• escape characters are omitted from the resulting pattern
• the pattern is wrapped by ^...$ to make sure the entire string is matched
• the reg exp wildcard . matches line breaks

Author:

Gunnar Morling

Constructor Summary

Constructors

Constructor and Description
LikeExpressionToRegExpConverter()
LikeExpressionToRegExpConverter(Character escapeCharacter)

Method Summary

Methods

Modifier and Type	Method and Description
Pattern	getRegExpFromLikeExpression(String likeExpression) Creates a regular expression pattern object equivalent to the given LIKE expression.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LikeExpressionToRegExpConverter

public LikeExpressionToRegExpConverter()

LikeExpressionToRegExpConverter

public LikeExpressionToRegExpConverter(Character escapeCharacter)

Method Detail

getRegExpFromLikeExpression

public Pattern getRegExpFromLikeExpression(String likeExpression)

Creates a regular expression pattern object equivalent to the given LIKE expression.

Parameters:

likeExpression - the HQL/JPQL LIKE expression to convert

Returns:

a regular expression pattern object equivalent to the given LIKE expression