Fixed dependency from opencv_nonfree in Java bindings

modules/java/CMakeLists.txt

@@ -6,7 +6,7 @@ if(NOT ANDROID OR NOT PYTHON_EXECUTABLE OR ANDROID_NATIVE_API_LEVEL LESS 8)
 endif()
 
 set(the_description "The java bindings")
-ocv_add_module(java BINDINGS opencv_core opencv_imgproc OPTIONAL opencv_objdetect opencv_features2d opencv_video opencv_highgui opencv_ml opencv_calib3d opencv_photo)
+ocv_add_module(java BINDINGS opencv_core opencv_imgproc OPTIONAL opencv_objdetect opencv_features2d opencv_video opencv_highgui opencv_ml opencv_calib3d opencv_photo opencv_nonfree)
 ocv_module_include_directories("${CMAKE_CURRENT_SOURCE_DIR}/src/cpp")
 
 # get list of modules to wrap
@@ -56,6 +56,7 @@ foreach(module ${OPENCV_JAVA_MODULES})
   endforeach()
 
   # first run (to get list of generated files)
+  if(module_headers)
     file(REMOVE_RECURSE "${CMAKE_CURRENT_BINARY_DIR}/gen_java_out/")
     file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/gen_java_out")
     execute_process(COMMAND ${PYTHON_EXECUTABLE} "${GEN_JAVA}" "${HDR_PARSER}" ${module} ${module_headers}
@@ -73,6 +74,7 @@ foreach(module ${OPENCV_JAVA_MODULES})
     list(APPEND java_hdr_deps ${module_headers})
     list(APPEND generated_cpp_sources "${CMAKE_CURRENT_BINARY_DIR}/${module}.cpp")
     list(APPEND generated_java_sources ${${module}_generated_java_sources})
+  endif()
 endforeach()
 
 # get handwritten files used for wrappers generation

modules/java/src/cpp/jni_part.cpp

@@ -22,3 +22,15 @@ JNI_OnUnload(JavaVM *vm, void *reserved)
 }
 
 } // extern "C"
+
+#include "opencv2/opencv_modules.hpp"
+
+#if HAVE_OPENCV_MODULES_NONFREE
+#include "opencv2/nonfree/nonfree.hpp"
+static bool makeUseOfNonfree = initModule_nonfree();
+#endif
+
+#if HAVE_OPENCV_MODULES_FEATURES2D
+#include "opencv2/features2d/features2d.hpp"
+static bool makeUseOfNonfree = initModule_features2d();
+#endif