Handle backslash characters for LIKE ESCAPE clause.

Hibernate HQL supports using a `\\` as the ESCAPE character so we need to support it in our custom parser.

See #3040

Author: gregturn

spring-data-jpa/src/main/antlr4/org/springframework/data/jpa/repository/query/Hql.g4

@@ -605,7 +605,7 @@ dealingWithNullExpression
 
 // https://docs.jboss.org/hibernate/orm/6.1/userguide/html_single/Hibernate_User_Guide.html#hql-like-predicate
 stringPatternMatching
-    : expression NOT? (LIKE | ILIKE) expression (ESCAPE (character|parameter))?
+    : expression NOT? (LIKE | ILIKE) expression (ESCAPE (stringLiteral|parameter))?
     ;
 
 // https://docs.jboss.org/hibernate/orm/6.1/userguide/html_single/Hibernate_User_Guide.html#hql-elements-indices
@@ -1078,7 +1078,7 @@ fragment HEX_DIGIT          : [0-9a-fA-F];
 
 
 CHARACTER                   : '\'' (~ ('\'' | '\\' )) '\'' ;
-STRINGLITERAL               : '\'' ('\'' '\'' | ~('\'' | '\\'))* '\'' ;
+STRINGLITERAL               : '\'' ('\'' '\'' | ~('\''))* '\'' ;
 JAVASTRINGLITERAL           : '"' ( ('\\' [btnfr"']) | ~('"'))* '"';
 INTEGER_LITERAL             : INTEGER_NUMBER (L | B I)? ;
 FLOAT_LITERAL               : FLOAT_NUMBER (D | F | B D)?;

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/HqlQueryRenderer.java

@@ -2231,8 +2231,9 @@ public List<JpaQueryParsingToken> visitStringPatternMatching(HqlParser.StringPat
 		if (ctx.ESCAPE() != null) {
 
 			tokens.add(new JpaQueryParsingToken(ctx.ESCAPE()));
-			if (ctx.character() != null) {
-				tokens.addAll(visit(ctx.character()));
+
+			if (ctx.stringLiteral() != null) {
+				tokens.addAll(visit(ctx.stringLiteral()));
 			} else if (ctx.parameter() != null) {
 				tokens.addAll(visit(ctx.parameter()));
 			}

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/query/HqlQueryRendererTests.java

@@ -1544,4 +1544,9 @@ void binaryLiteralsShouldWork() {
 		assertQuery("SELECT ce.id FROM CalendarEvent ce WHERE ce.value = X'DEADBEEF'");
 		assertQuery("SELECT ce.id FROM CalendarEvent ce WHERE ce.value = x'deadbeef'");
 	}
+
+	@Test // GH-3040
+	void escapeClauseShouldWork() {
+		assertQuery("select t.name from SomeDbo t where t.name LIKE :name escape '\\\\'");
+	}
 }