From b6b386893e097da353bbcb5b8668e38409ff8a40 Mon Sep 17 00:00:00 2001
From: Oliver Gierke <info@olivergierke.de>
Date: Tue, 23 Aug 2011 09:04:20 +0200
Subject: [PATCH] DATADOC-90 - Fixed potential concurrency problem for PartTree
 based query creation.

We now eagerly create CriteriaQuery and it's ParameterExpressions in QueryPreparer's constructor. Lazily doing so could let to exceptions accessing the ParameterExpressions in race conditions.
---
 .../repository/query/PartTreeJpaQuery.java    | 43 +++++++++++++------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/src/main/java/org/springframework/data/jpa/repository/query/PartTreeJpaQuery.java b/src/main/java/org/springframework/data/jpa/repository/query/PartTreeJpaQuery.java
index cdb6bda3b..137c2578a 100644
--- a/src/main/java/org/springframework/data/jpa/repository/query/PartTreeJpaQuery.java
+++ b/src/main/java/org/springframework/data/jpa/repository/query/PartTreeJpaQuery.java
@@ -58,8 +58,10 @@ public class PartTreeJpaQuery extends AbstractJpaQuery {
         this.tree = new PartTree(method.getName(), domainClass);
         this.parameters = method.getParameters();
 
-        this.query = new QueryPreparer();
-        this.countQuery = new CountQueryPreparer();
+        this.query =
+                new QueryPreparer(parameters.potentiallySortsDynamically());
+        this.countQuery =
+                new CountQueryPreparer(parameters.potentiallySortsDynamically());
     }
 
 
@@ -98,8 +100,17 @@ public class PartTreeJpaQuery extends AbstractJpaQuery {
      */
     private class QueryPreparer {
 
-        private CriteriaQuery<?> query;
-        private JpaQueryCreator creator;
+        private final CriteriaQuery<?> query;
+        private final List<ParameterExpression<?>> expressions;
+
+
+        public QueryPreparer(boolean recreateQueries) {
+
+            JpaQueryCreator creator = createCreator();
+            this.query = recreateQueries ? null : creator.createQuery();
+            this.expressions =
+                    recreateQueries ? null : creator.getParameterExpressions();
+        }
 
 
         /**
@@ -110,16 +121,18 @@ public class PartTreeJpaQuery extends AbstractJpaQuery {
          */
         public Query createQuery(Object[] values) {
 
-            if (parameters.potentiallySortsDynamically() || query == null
-                    || creator == null) {
-                creator = createCreator();
-                query = creator.createQuery(getDynamicSort(values));
+            CriteriaQuery<?> criteriaQuery = query;
+            List<ParameterExpression<?>> expressions = this.expressions;
+
+            if (query == null) {
+                JpaQueryCreator creator = createCreator();
+                criteriaQuery = creator.createQuery(getDynamicSort(values));
+                expressions = creator.getParameterExpressions();
             }
 
-            TypedQuery<?> jpaQuery = getEntityManager().createQuery(query);
-            return invokeBinding(
-                    getBinder(values, creator.getParameterExpressions()),
-                    jpaQuery);
+            TypedQuery<?> jpaQuery =
+                    getEntityManager().createQuery(criteriaQuery);
+            return invokeBinding(getBinder(values, expressions), jpaQuery);
         }
 
 
@@ -166,6 +179,12 @@ public class PartTreeJpaQuery extends AbstractJpaQuery {
      */
     private class CountQueryPreparer extends QueryPreparer {
 
+        public CountQueryPreparer(boolean recreateQueries) {
+
+            super(recreateQueries);
+        }
+
+
         /*
          * (non-Javadoc)
          *