Fixed Algorithm.save and other methods work in Java

modules/java/generator/gen_java.py

@@ -1005,7 +1005,7 @@ class JavaWrapperGenerator(object):
         type_dict["Ptr_"+name] = \
             { "j_type" : classinfo.jname,
               "jn_type" : "long", "jn_args" : (("__int64", ".nativeObj"),),
-              "jni_name" : "Ptr<"+classinfo.fullName(isCPP=True)+">(("+classinfo.fullName(isCPP=True)+"*)%(n)s_nativeObj)", "jni_type" : "jlong",
+              "jni_name" : "*((Ptr<"+classinfo.fullName(isCPP=True)+">*)%(n)s_nativeObj)", "jni_type" : "jlong",
               "suffix" : "J" }
         logging.info('ok: class %s, name: %s, base: %s', classinfo, name, classinfo.base)
 
@@ -1575,7 +1575,7 @@ JNIEXPORT void JNICALL Java_org_opencv_%(module)s_%(j_cls)s_delete
         # if parents are smart (we hope) then children are!
         # if not we believe the class is smart if it has "create" method
         ci.smart = False
-        if ci.base:
+        if ci.base or ci.name == 'Algorithm':
             ci.smart = True
         else:
             for fi in ci.methods:

modules/ml/misc/java/test/MLTest.java

+package org.opencv.test.ml;
+
+import org.opencv.ml.Ml;
+import org.opencv.ml.SVM;
+import org.opencv.core.Mat;
+import org.opencv.core.MatOfFloat;
+import org.opencv.core.MatOfInt;
+import org.opencv.core.CvType;
+import org.opencv.test.OpenCVTestCase;
+import org.opencv.test.OpenCVTestRunner;
+
+public class MLTest extends OpenCVTestCase {
+
+    public void testSaveLoad() {
+        Mat samples = new MatOfFloat(new float[] {
+            5.1f, 3.5f, 1.4f, 0.2f,
+            4.9f, 3.0f, 1.4f, 0.2f,
+            4.7f, 3.2f, 1.3f, 0.2f,
+            4.6f, 3.1f, 1.5f, 0.2f,
+            5.0f, 3.6f, 1.4f, 0.2f,
+            7.0f, 3.2f, 4.7f, 1.4f,
+            6.4f, 3.2f, 4.5f, 1.5f,
+            6.9f, 3.1f, 4.9f, 1.5f,
+            5.5f, 2.3f, 4.0f, 1.3f,
+            6.5f, 2.8f, 4.6f, 1.5f
+        }).reshape(1, 10);
+        Mat responses = new MatOfInt(new int[] {
+            0, 0, 0, 0, 0, 1, 1, 1, 1, 1
+        }).reshape(1, 10);
+        SVM saved = SVM.create();
+        assertFalse(saved.isTrained());
+
+        saved.train(samples, Ml.ROW_SAMPLE, responses);
+        assertTrue(saved.isTrained());
+
+        String filename = OpenCVTestRunner.getTempFileName("yml");
+        saved.save(filename);
+        SVM loaded = SVM.load(filename);
+        assertTrue(saved.isTrained());
+    }
+
+}