Support Contains with ElementCollection of type String.

Properly handle `contains` for an ElementCollection of type String in a LIKE query, wrapping the the parameter in wildcards only when needed.

Closes: #2607.

Author: schauder

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

@@ -196,6 +196,7 @@ static class ParameterMetadata<T> {
 		private final ParameterExpression<T> expression;
 		private final EscapeCharacter escape;
 		private final boolean ignoreCase;
+		private final boolean noWildcards;
 
 		/**
 		 * Creates a new {@link ParameterMetadata}.
@@ -206,6 +207,7 @@ public ParameterMetadata(ParameterExpression<T> expression, Part part, @Nullable
 			this.expression = expression;
 			this.type = value == null && Type.SIMPLE_PROPERTY.equals(part.getType()) ? Type.IS_NULL : part.getType();
 			this.ignoreCase = IgnoreCaseType.ALWAYS.equals(part.shouldIgnoreCase());
+			this.noWildcards = part.getProperty().getLeafProperty().isCollection();
 			this.escape = escape;
 		}
 
@@ -241,7 +243,7 @@ public Object prepare(Object value) {
 				return value;
 			}
 
-			if (String.class.equals(expressionType)) {
+			if (String.class.equals(expressionType) && !noWildcards) {
 
 				switch (type) {
 					case STARTING_WITH:

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

@@ -2968,6 +2968,24 @@ void complexWithNativeStatement() {
 		assertThat(foundData).containsExactly("joachim", "dave", "kevin");
 	}
 
+	@Test // GH-2607
+	void containsWithCollection(){
+
+		firstUser.getAttributes().add("cool");
+		firstUser.getAttributes().add("hip");
+
+		secondUser.getAttributes().add("hip");
+
+		thirdUser.getAttributes().add("rockstar");
+		thirdUser.getAttributes().add("%hip%");
+
+		flushTestUsers();
+
+		List<User> result = repository.findByAttributesContains("hip");
+
+		assertThat(result).containsOnly(firstUser, secondUser);
+	}
+
 	private Page<User> executeSpecWithSort(Sort sort) {
 
 		flushTestUsers();

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/sample/UserRepository.java

@@ -676,6 +676,9 @@ List<String> findAllAndSortByFunctionResultNamedParameter(@Param("namedParameter
 			nativeQuery = true)
 	List<String> complexWithNativeStatement();
 
+	// GH-2607
+	List<User> findByAttributesContains(String attribute);
+
 	interface RolesAndFirstname {
 
 		String getFirstname();