diff --git a/src/corelib/time/qtimezoneprivate_android.cpp b/src/corelib/time/qtimezoneprivate_android.cpp
index 43a4593104d..c4ca0e42146 100644
--- a/src/corelib/time/qtimezoneprivate_android.cpp
+++ b/src/corelib/time/qtimezoneprivate_android.cpp
@@ -10,6 +10,11 @@
 
 QT_BEGIN_NAMESPACE
 
+Q_DECLARE_JNI_CLASS(TimeZone, "java/util/TimeZone");
+Q_DECLARE_JNI_CLASS(Locale, "java/util/Locale");
+Q_DECLARE_JNI_CLASS(Date, "java/util/Date");
+Q_DECLARE_JNI_TYPE(StringArray, "[Ljava/lang/String;")
+
 /*
     Private
 
@@ -25,9 +30,9 @@ QAndroidTimeZonePrivate::QAndroidTimeZonePrivate()
     : QTimeZonePrivate()
 {
     // Keep in sync with systemTimeZoneId():
-    androidTimeZone = QJniObject::callStaticObjectMethod(
-        "java.util.TimeZone", "getDefault", "()Ljava/util/TimeZone;");
-    const QJniObject id = androidTimeZone.callObjectMethod("getID", "()Ljava/lang/String;");
+    androidTimeZone = QJniObject::callStaticMethod<QtJniTypes::TimeZone>(
+                          QtJniTypes::className<QtJniTypes::TimeZone>(), "getDefault");
+    const QJniObject id = androidTimeZone.callMethod<jstring>("getID");
     m_id = id.toString().toUtf8();
 }
 
@@ -53,20 +58,19 @@ static QString getDisplayName(QJniObject zone, jint style, jboolean dst,
                                         const QLocale &locale)
 {
     QJniObject jbcpTag = QJniObject::fromString(locale.bcp47Name());
-    QJniObject jlocale = QJniObject::callStaticObjectMethod(
-                "java/util/Locale", "forLanguageTag", "(Ljava/lang/String;)Ljava/util/Locale;",
+    QJniObject jlocale = QJniObject::callStaticMethod<QtJniTypes::Locale>(
+                QtJniTypes::className<QtJniTypes::Locale>(), "forLanguageTag",
                 jbcpTag.object<jstring>());
 
-    return zone.callObjectMethod("getDisplayName",
-                                 "(ZILjava/util/Locale;)Ljava/lang/String;",
-                                 dst, style, jlocale.object()).toString();
+    return zone.callMethod<jstring>("getDisplayName", dst, style,
+                                     jlocale.object<QtJniTypes::Locale>()).toString();
 }
 
 void QAndroidTimeZonePrivate::init(const QByteArray &ianaId)
 {
     const QString iana = QString::fromUtf8(ianaId);
-    androidTimeZone = QJniObject::callStaticObjectMethod(
-        "java.util.TimeZone", "getTimeZone", "(Ljava/lang/String;)Ljava/util/TimeZone;",
+    androidTimeZone = QJniObject::callStaticMethod<QtJniTypes::TimeZone>(
+        QtJniTypes::className<QtJniTypes::TimeZone>(), "getTimeZone",
         QJniObject::fromString(iana).object<jstring>());
 
     // The ID or display name of the zone we've got, if it looks like what we asked for:
@@ -81,7 +85,7 @@ void QAndroidTimeZonePrivate::init(const QByteArray &ianaId)
     // recognize the name; so check for whether ianaId is a recognized name of
     // the zone object we got and ignore the zone if not.
     // Try checking ianaId against getID(), getDisplayName():
-    m_id = match(androidTimeZone.callObjectMethod("getID", "()Ljava/lang/String;").toString());
+    m_id = match(androidTimeZone.callMethod<jstring>("getID").toString());
     for (int style = 1; m_id.isEmpty() && style >= 0; --style) {
         for (int dst = 1; m_id.isEmpty() && dst >= 0; --dst) {
             for (int pick = 2; m_id.isEmpty() && pick >= 0; --pick) {
@@ -128,11 +132,13 @@ int QAndroidTimeZonePrivate::offsetFromUtc(qint64 atMSecsSinceEpoch) const
 {
     // offsetFromUtc( ) is invoked when androidTimeZone may not yet be set at startup,
     // so a validity test is needed here
-    if ( androidTimeZone.isValid() )
+    if ( androidTimeZone.isValid() ) {
         // the java method getOffset() returns milliseconds, but QTimeZone returns seconds
-        return androidTimeZone.callMethod<jint>( "getOffset", "(J)I", static_cast<jlong>(atMSecsSinceEpoch) ) / 1000;
-    else
+        return androidTimeZone.callMethod<jint>(
+                              "getOffset", static_cast<jlong>(atMSecsSinceEpoch) ) / 1000;
+    } else {
         return 0;
+    }
 }
 
 int QAndroidTimeZonePrivate::standardTimeOffset(qint64 atMSecsSinceEpoch) const
@@ -163,8 +169,10 @@ bool QAndroidTimeZonePrivate::hasDaylightTime() const
 bool QAndroidTimeZonePrivate::isDaylightTime(qint64 atMSecsSinceEpoch) const
 {
     if ( androidTimeZone.isValid() ) {
-        QJniObject jDate( "java/util/Date", "(J)V", static_cast<jlong>(atMSecsSinceEpoch) );
-        return androidTimeZone.callMethod<jboolean>("inDaylightTime", "(Ljava/util/Date;)Z", jDate.object() );
+        QJniObject jDate = QJniObject::construct<QtJniTypes::Date>(
+                                                   static_cast<jlong>(atMSecsSinceEpoch));
+        return androidTimeZone.callMethod<jboolean>("inDaylightTime",
+                                                     jDate.object<QtJniTypes::Date>());
     }
     else
         return false;
@@ -191,16 +199,17 @@ QTimeZonePrivate::Data QAndroidTimeZonePrivate::data(qint64 forMSecsSinceEpoch)
 QByteArray QAndroidTimeZonePrivate::systemTimeZoneId() const
 {
     // Keep in sync with default constructor:
-    QJniObject androidSystemTimeZone = QJniObject::callStaticObjectMethod(
-        "java.util.TimeZone", "getDefault", "()Ljava/util/TimeZone;");
-    const QJniObject id = androidSystemTimeZone.callObjectMethod<jstring>("getID");
+    QJniObject androidSystemTimeZone = QJniObject::callStaticMethod<QtJniTypes::TimeZone>(
+                              QtJniTypes::className<QtJniTypes::TimeZone>(), "getDefault");
+    const QJniObject id = androidSystemTimeZone.callMethod<jstring>("getID");
     return id.toString().toUtf8();
 }
 
 QList<QByteArray> QAndroidTimeZonePrivate::availableTimeZoneIds() const
 {
     QList<QByteArray> availableTimeZoneIdList;
-    QJniObject androidAvailableIdList = QJniObject::callStaticObjectMethod("java.util.TimeZone", "getAvailableIDs", "()[Ljava/lang/String;");
+    QJniObject androidAvailableIdList = QJniObject::callStaticMethod<QtJniTypes::StringArray>(
+                             QtJniTypes::className<QtJniTypes::TimeZone>(), "getAvailableIDs");
 
     QJniEnvironment jniEnv;
     int androidTZcount = jniEnv->GetArrayLength(androidAvailableIdList.object<jarray>());