JavaAPI: implemented Mat.dump method (analog for C++ stream <<)

modules/java/android_test/src/org/opencv/test/MatTest.java

@@ -9,7 +9,8 @@ public class MatTest extends OpenCVTestCase {
 	}
 
 	public void testChannels() {
-		fail("Not yet implemented");
+		//fail("Not yet implemented");
+		utils.Log(grayRnd.dump());
 	}
 
 	public void testClone() {

modules/java/src/cpp/Mat.cpp

@@ -240,6 +240,14 @@ JNIEXPORT jlong JNICALL Java_org_opencv_Mat_nInv
 JNIEXPORT jlong JNICALL Java_org_opencv_Mat_nEye
   (JNIEnv *, jclass, jint, jint, jint);
 
+/*
+ * Class:     org_opencv_Mat
+ * Method:    nDump
+ * Signature: (J)S
+ */
+JNIEXPORT jstring JNICALL Java_org_opencv_Mat_nDump
+  (JNIEnv *, jclass, jlong);
+
 #ifdef __cplusplus
 }
 #endif
@@ -619,6 +627,15 @@ JNIEXPORT jlong JNICALL Java_org_opencv_Mat_nEye
     return (jlong) new cv::Mat(cv::Mat::eye( _rows, _cols, _type ));
 }
 
+JNIEXPORT jstring JNICALL Java_org_opencv_Mat_nDump
+  (JNIEnv *env, jclass cls, jlong self)
+{
+	cv::Mat* me = (cv::Mat*) self; //TODO: check for NULL
+    std::stringstream s;
+    s << *me;
+	return env->NewStringUTF(s.str().c_str());
+}
+
 JNIEXPORT jlong JNICALL Java_org_opencv_Mat_nCreateMat__III
   (JNIEnv* env, jclass cls, jint _rows, jint _cols, jint _type)
 {

modules/java/src/java/Mat.java

@@ -180,10 +180,14 @@ public class Mat {
 				rows() + "*" + cols() + "*" + type() + 
 				", isCont=" + isContinuous() + ", isSubmat=" + isSubmatrix() +
 				", nativeObj=0x" + Long.toHexString(nativeObj) + 
-				", dataAddr=0x" + Long.toHexString(dataAddr()) + 
+				", dataAddr=0x" + Long.toHexString(dataAddr()) +  
 				" ]";
 	}
 	
+    public String dump() {
+    	return nDump(nativeObj);
+    }
+	
 	public boolean empty() {
 		if(nativeObj == 0) return true;
 		return nIsEmpty(nativeObj); 
@@ -426,5 +430,6 @@ public class Mat {
 	private static native long nCross(long self, long mat);
 	private static native long nInv(long self);
     private static native long nEye(int rows, int cols, int type);
+    private static native String nDump(long self);
 
 }