DATAJPA-798 - Alias detection now also works for JPQL strings containing line breaks.

We tweaked the regular expression to detect query aliases to correctly use the whitespace character class \s instead of a simple space to make sure we don't get fooled by other whitespace characters like tabs and line breaks.

Author: odrotbohm

src/main/java/org/springframework/data/jpa/repository/query/QueryUtils.java

@@ -84,7 +84,7 @@ public abstract class QueryUtils {
 	private static final String IDENTIFIER = "[\\p{Lu}\\P{InBASIC_LATIN}\\p{Alnum}._$]+";
 	private static final String IDENTIFIER_GROUP = String.format("(%s)", IDENTIFIER);
 
-	private static final String JOIN = "join " + IDENTIFIER + " (as )?" + IDENTIFIER_GROUP;
+	private static final String JOIN = "join\\s" + IDENTIFIER + "\\s(as\\s)?" + IDENTIFIER_GROUP;
 	private static final Pattern JOIN_PATTERN = Pattern.compile(JOIN, Pattern.CASE_INSENSITIVE);
 
 	private static final String EQUALS_CONDITION_STRING = "%s.%s = :%s";
@@ -102,10 +102,10 @@ public abstract class QueryUtils {
 
 		StringBuilder builder = new StringBuilder();
 		builder.append("(?<=from)"); // from as starting delimiter
-		builder.append("(?: )+"); // at least one space separating
+		builder.append("(?:\\s)+"); // at least one space separating
 		builder.append(IDENTIFIER_GROUP); // Entity name, can be qualified (any
-		builder.append("(?: as)*"); // exclude possible "as" keyword
-		builder.append("(?: )+"); // at least one space separating
+		builder.append("(?:\\sas)*"); // exclude possible "as" keyword
+		builder.append("(?:\\s)+"); // at least one space separating
 		builder.append("(\\w*)"); // the actual alias
 
 		ALIAS_MATCH = compile(builder.toString(), CASE_INSENSITIVE);

src/test/java/org/springframework/data/jpa/repository/query/QueryUtilsUnitTests.java

@@ -303,6 +303,14 @@ public void supportsNonAsciiCharactersInEntityNames() {
 		assertThat(createCountQueryFor("select u from Usèr u"), is("select count(u) from Usèr u"));
 	}
 
+	/**
+	 * @see DATAJPA-798
+	 */
+	@Test
+	public void detectsAliasInQueryContainingLineBreaks() {
+		assertThat(detectAlias("select \n u \n from \n User \nu"), is("u"));
+	}
+
 	private void assertCountQuery(String originalQuery, String countQuery) {
 		assertThat(createCountQueryFor(originalQuery), is(countQuery));
 	}