QJniArray: find the java/lang/String class from the cache

Don't look it up through JNIEnv::FindString, use our internal cache. For
that (and as we don't want to instantiate a temporary QJniEnvironment)
we need to use the QtAndroidPrivate internal symbol, which then needs to
be forward declared.

Change-Id: I4a69bf973fbdc1df6939f5ce94878588a4fcbd3d
Reviewed-by: Assam Boudjelthia <[email protected]>
Reviewed-by: Soheil Armin <[email protected]>

1 files changed, 7 insertions, 1 deletions

diff --git a/src/corelib/kernel/qjniarray.h b/src/corelib/kernel/qjniarray.h
index cd85ae48043..68268790632 100644
--- a/src/corelib/kernel/qjniarray.h
+++ b/src/corelib/kernel/qjniarray.h
@@ -24,6 +24,12 @@ QT_BEGIN_NAMESPACE
 template <typename T> class QJniArray;
 template <typename T> struct QJniArrayMutableIterator;
 
+// forward declare here so that we don't have to include the private header
+namespace QtAndroidPrivate
+{
+    Q_CORE_EXPORT jclass findClass(const char *className, JNIEnv *env);
+}
+
 template <typename T>
 struct QJniArrayIterator
 {
@@ -915,7 +921,7 @@ auto QJniArrayBase::makeObjectArray(List &&list)
                                      std::is_base_of<QtJniTypes::JObjectBase, ElementType>>) {
         elementClass = std::begin(list)->objectClass();
     } else if constexpr (std::is_same_v<ElementType, QString>) {
-        elementClass = env->FindClass("java/lang/String");
+        elementClass = QtAndroidPrivate::findClass("java/lang/String", env);
     } else {
         elementClass = env->GetObjectClass(*std::begin(list));
     }