DATAJPA-292 - Manually defined queries can contain like expressions now.

This commit introduces support for JPQL inline like expressions such as "… like ?1%". The implementation will detect those expressions and turn the query back into a valid JPQL one. On query execution the parameters will be bound according to the like expression defined in the query.

Author: odrotbohm

src/docbkx/jpa.xml

@@ -508,6 +508,31 @@ public class User {
 }</programlisting>
       </example>
 
+      <simplesect>
+        <title>Using advanced <code>LIKE</code> expressions</title>
+
+        <para>The query execution mechanism for manually defined queries using
+        <interfacename>@Query</interfacename> allow the definition of advanced
+        <code>LIKE</code> expressions inside the query definition.</para>
+
+        <example>
+          <title>Advanced <code>LIKE</code> expressions in
+          <interfacename>@Query</interfacename></title>
+
+          <programlisting language="java">public interface UserRepository extends JpaRepository&lt;User, Long&gt; {
+
+  @Query("select u from User u where u.firstname like %?1")
+  List&lt;User&gt; findByFirstnameEndsWith(String firstname);
+}</programlisting>
+        </example>
+
+        <para>In the just shown sample <code>LIKE</code> delimiter character
+        <code>%</code> is recognized and the query transformed into a valid
+        JPQL query (removing the <code>%</code>). Upon query execution the
+        parameter handed into the method call gets augmented with the
+        previously recognized <code>LIKE</code> pattern.</para>
+      </simplesect>
+
       <simplesect>
         <title>Native queries</title>
 

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

@@ -37,9 +37,8 @@ final class SimpleJpaQuery extends AbstractJpaQuery {
 
 	private static final Logger LOG = LoggerFactory.getLogger(SimpleJpaQuery.class);
 
-	private final String queryString;
-	private final String countQuery;
-	private final String alias;
+	private final StringQuery query;
+	private final StringQuery countQuery;
 
 	private final JpaQueryMethod method;
 
@@ -50,11 +49,10 @@ final class SimpleJpaQuery extends AbstractJpaQuery {
 
 		super(method, em);
 
-		this.queryString = queryString;
-		this.alias = QueryUtils.detectAlias(queryString);
-		this.countQuery = method.getCountQuery() == null ? QueryUtils.createCountQueryFor(queryString) : method
-				.getCountQuery();
 		this.method = method;
+		this.query = new StringQuery(queryString);
+		this.countQuery = new StringQuery(method.getCountQuery() == null ? QueryUtils.createCountQueryFor(queryString)
+				: method.getCountQuery());
 
 		Parameters parameters = method.getParameters();
 		boolean hasPagingOrSortingParameter = parameters.hasPageableParameter() || parameters.hasSortParameter();
@@ -66,7 +64,7 @@ final class SimpleJpaQuery extends AbstractJpaQuery {
 		// Try to create a Query object already to fail fast
 		if (!method.isNativeQuery()) {
 			try {
-				em.createQuery(queryString);
+				em.createQuery(query.getQuery());
 			} catch (RuntimeException e) {
 				// Needed as there's ambiguities in how an invalid query string shall be expressed by the persistence provider
 				// http://java.net/projects/jpa-spec/lists/jsr338-experts/archive/2012-07/message/17
@@ -82,6 +80,15 @@ final class SimpleJpaQuery extends AbstractJpaQuery {
 		this(method, em, method.getAnnotatedQuery());
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.jpa.repository.query.AbstractJpaQuery#createBinder(java.lang.Object[])
+	 */
+	@Override
+	protected ParameterBinder createBinder(Object[] values) {
+		return new StringQueryParameterBinder(getQueryMethod().getParameters(), values, query);
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.jpa.repository.query.AbstractJpaQuery#createQuery(java.lang.Object[])
@@ -90,7 +97,7 @@ final class SimpleJpaQuery extends AbstractJpaQuery {
 	public Query doCreateQuery(Object[] values) {
 
 		ParameterAccessor accessor = new ParametersParameterAccessor(method.getParameters(), values);
-		String sortedQueryString = QueryUtils.applySorting(queryString, accessor.getSort(), alias);
+		String sortedQueryString = QueryUtils.applySorting(query.getQuery(), accessor.getSort(), query.getAlias());
 		EntityManager em = getEntityManager();
 
 		Query query = null;
@@ -111,8 +118,7 @@ public Query doCreateQuery(Object[] values) {
 	 */
 	@Override
 	protected TypedQuery<Long> doCreateCountQuery(Object[] values) {
-
-		return createBinder(values).bind(getEntityManager().createQuery(countQuery, Long.class));
+		return createBinder(values).bind(getEntityManager().createQuery(countQuery.getQuery(), Long.class));
 	}
 
 	/**
@@ -131,4 +137,4 @@ public static RepositoryQuery fromQueryAnnotation(JpaQueryMethod queryMethod, En
 
 		return query == null ? null : new SimpleJpaQuery(queryMethod, em, query);
 	}
-}
+}