Added an object that lets you hold a copyable reference to a java array. Also

renamed the objects and generally improved documentation.

dlib/java/cmake_swig_jni

@@ -119,8 +119,26 @@ FILE(WRITE ${CMAKE_CURRENT_BINARY_DIR}/swig.i
     %module global 
 
     %{
-    #include \"swig_api.h\"
     #include <exception>
+    #include <stdexcept>
+    static JavaVM *cached_jvm = 0;
+
+    JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *jvm, void *reserved) {
+        cached_jvm = jvm;
+        return JNI_VERSION_1_6;
+    }
+
+    static JNIEnv * JNI_GetEnv() {
+        JNIEnv *env;
+        jint rc = cached_jvm->GetEnv((void **)&env, JNI_VERSION_1_6);
+        if (rc == JNI_EDETACHED)
+            throw std::runtime_error(\"current thread not attached\");
+        if (rc == JNI_EVERSION)
+            throw std::runtime_error(\"jni version not supported\");
+        return env;
+    }
+
+    #include \"swig_api.h\"
     %}
 
     // Convert all C++ exceptions into java.lang.Exception

dlib/java/swig_api.h

 #ifndef EXAMPLE_SWIG_ApI_H_ 
 #define EXAMPLE_SWIG_ApI_H_
 
-// This file is essentially a small unit test for the swig cmake scripts and the jvector
+// This file is essentially a small unit test for the swig cmake scripts and the java array
 // classes.  All it does it define a few simple functions for writing to and summing
 // arrays.  The swig_test.java file then calls these C++ functions and checks if they work
 // correctly.  
 
 
 
-// Let's use the jvector, a tool for efficiently binding java native arrays to C++ function
-// arguments.  You do this by putting this pair of include statements in your swig_api.h
-// file.  Then after that you can use the jvector and jvector_crit classes.  
-#include "jvector.h"
+// Let's use java_array.h, a tool for efficiently binding java native arrays to C++
+// function arguments.  You do this by putting this pair of include statements in your
+// swig_api.h file.  Then after that you can use the java::array, java::array_view, and
+// java::array_view_crit classes.  
+#include "java_array.h"
 #ifdef SWIG
-%include "jvector.h"
+%include "java_array.h"
 #endif
 
 
-// ----------------------------------------------------------------------------------------
+using namespace java;
+
 
 // SWIG can't expose templated functions to java.  We declare these here as helper
 // functions to make the non-templated routines swig will expose easier to write.  You can
 // see these java exposed methods below (i.e. sum(), sum_crit(), assign(), and
 // assign_crit()).
 template <typename T>
-T tsum(const jvector_crit<T>& arr)
+T tsum(const array_view_crit<T>& arr)
 {
     T s = 0;
     for (auto& v : arr)
@@ -32,7 +34,7 @@ T tsum(const jvector_crit<T>& arr)
     return s;
 }
 template <typename T>
-T tsum(const jvector<T>& arr)
+T tsum(const array_view<T>& arr)
 {
     T s = 0;
     for (auto& v : arr)
@@ -56,41 +58,64 @@ void tassign(T& arr)
 // "global", which is where these sum and assign routines will appear.  You can see
 // examples of java code that calls them in swig_test.java.
 
-inline int sum_crit(const jvector_crit<int16_t>& arr) { return tsum(arr); }
-inline int sum(const jvector<int16_t>& arr) { return tsum(arr); }
-inline void assign_crit(jvector_crit<int16_t>& arr) { tassign(arr); }
-inline void assign(jvector<int16_t>& arr) { tassign(arr); }
+inline int sum_crit(const array_view_crit<int16_t>& arr) { return tsum(arr); }
+inline int sum(const array_view<int16_t>& arr) { return tsum(arr); }
+inline void assign_crit(array_view_crit<int16_t>& arr) { tassign(arr); }
+inline void assign(array_view<int16_t>& arr) { tassign(arr); }
 
 
-inline int sum_crit(const jvector_crit<int32_t>& arr) { return tsum(arr); }
-inline int sum(const jvector<int32_t>& arr) { return tsum(arr); }
-inline void assign_crit(jvector_crit<int32_t>& arr) { tassign(arr); }
-inline void assign(jvector<int32_t>& arr) { tassign(arr); }
+inline int sum_crit(const array_view_crit<int32_t>& arr) { return tsum(arr); }
+inline int sum(const array_view<int32_t>& arr) { return tsum(arr); }
+inline void assign_crit(array_view_crit<int32_t>& arr) { tassign(arr); }
+inline void assign(array_view<int32_t>& arr) { tassign(arr); }
 
 
-inline int sum_crit(const jvector_crit<int64_t>& arr) { return tsum(arr); }
-inline int sum(const jvector<int64_t>& arr) { return tsum(arr); }
-inline void assign_crit(jvector_crit<int64_t>& arr) { tassign(arr); }
-inline void assign(jvector<int64_t>& arr) { tassign(arr); }
+inline int sum_crit(const array_view_crit<int64_t>& arr) { return tsum(arr); }
+inline int sum(const array_view<int64_t>& arr) { return tsum(arr); }
+inline void assign_crit(array_view_crit<int64_t>& arr) { tassign(arr); }
+inline void assign(array_view<int64_t>& arr) { tassign(arr); }
 
 
-inline int sum_crit(const jvector_crit<char>& arr) { return tsum(arr); }
-inline int sum(const jvector<char>& arr) { return tsum(arr); }
-inline void assign_crit(jvector_crit<char>& arr) { tassign(arr); }
-inline void assign(jvector<char>& arr) { tassign(arr); }
+inline int sum_crit(const array_view_crit<char>& arr) { return tsum(arr); }
+inline int sum(const array_view<char>& arr) { return tsum(arr); }
+inline void assign_crit(array_view_crit<char>& arr) { tassign(arr); }
+inline void assign(array_view<char>& arr) { tassign(arr); }
 
 
 
-inline double sum_crit(const jvector_crit<double>& arr) { return tsum(arr); }
-inline double sum(const jvector<double>& arr) { return tsum(arr); }
-inline void assign_crit(jvector_crit<double>& arr) { tassign(arr); }
-inline void assign(jvector<double>& arr) { tassign(arr); }
+inline double sum_crit(const array_view_crit<double>& arr) { return tsum(arr); }
+inline double sum(const array_view<double>& arr) { return tsum(arr); }
+inline void assign_crit(array_view_crit<double>& arr) { tassign(arr); }
+inline void assign(array_view<double>& arr) { tassign(arr); }
 
 
-inline float sum_crit(const jvector_crit<float>& arr) { return tsum(arr); }
-inline float sum(const jvector<float>& arr) { return tsum(arr); }
-inline void assign_crit(jvector_crit<float>& arr) { tassign(arr); }
-inline void assign(jvector<float>& arr) { tassign(arr); }
+inline float sum_crit(array<float> arr) 
+{ 
+    array_view_crit<float> a(arr);
+    return tsum(a); 
+}
+inline float sum(const array<float>& arr) 
+{ 
+    array_view<float> a(arr);
+    return tsum(a); 
+}
+inline void assign_crit(array_view_crit<float>& arr) { tassign(arr); }
+inline void assign(array<float>& arr) 
+{ 
+    array_view<float> a(arr);
+    tassign(a); 
+}
+
+array<int32_t> make_an_array(size_t s)
+{
+    array<int32_t> arr(s);
+    array_view_crit<int32_t> a(arr);
+
+    for (size_t i = 0; i < a.size(); ++i)
+        a[i] = i;
+
+    return arr;
+}
 
 
 // ----------------------------------------------------------------------------------------

dlib/java/swig_test.java

@@ -69,6 +69,14 @@ public class swig_test
         }
     }
 
+    public static void assertIsEqual(int val1, int val2)
+    {
+        if (val1 != val2)
+        {
+            throw new RuntimeException("Test failed " + val1 + " should be equal to " + val2);
+        }
+    }
+
     public static double sum(double[] arr)
     {
         double s = 0;
@@ -233,6 +241,13 @@ public class swig_test
                 assertIs28(global.sum_crit(arr));
             }
         }
+        {
+            int[] a = global.make_an_array(4);
+            for (int i = 0; i < a.length; ++i)
+            {
+                assertIsEqual(a[i], i);
+            }
+        }
 
         System.out.println("\n\n   ALL TESTS COMPLETED SUCCESSFULLY\n");
     }