ConcurrentHashMap for JdbcMessageStore.queryCache

To avoid a possible `ConcurrentModificationException` it is better to use a
`ConcurrentHashMap` for that `computeIfAbsent()` operation on the cache

Author: artembilan

spring-integration-jdbc/src/main/java/org/springframework/integration/jdbc/store/JdbcMessageStore.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,11 +22,11 @@
 import java.sql.Timestamp;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Stream;
 
 import javax.sql.DataSource;
@@ -171,7 +171,7 @@ public String getSql() {
 
 	private final String vendorName;
 
-	private final Map<Query, String> queryCache = new HashMap<>();
+	private final Map<Query, String> queryCache = new ConcurrentHashMap<>();
 
 	private String region = "DEFAULT";