Support Array<jbyte> <-> std::string conversions.

Array<jbyte> <-> std::string conversions are needed to push protocol buffers
across jni boundaries by serializing and deserializing.

Author: spinorx

include/jni/array.hpp

@@ -180,4 +180,22 @@ namespace jni
         SetArrayRegion(env, *result, 0, array);
         return result;
        }
+
+    inline
+    std::string MakeAnything(ThingToMake<std::string>, JNIEnv& env, const Array<jbyte>& array)
+       {
+        NullCheck(env, array.Get());
+        std::string result;
+        result.resize(GetArrayLength(env, *array));
+        GetArrayRegion(env, *array, 0, result.size(), reinterpret_cast<jbyte*>(&result[0]));
+        return result;
+       }
+
+    inline
+    Array<jbyte> MakeAnything(ThingToMake<Array<jbyte>>, JNIEnv& env, const std::string& string)
+       {
+        Array<jbyte> result(&NewArray<jbyte>(env, string.size()));
+        SetArrayRegion(env, *result, 0, string.size(), reinterpret_cast<const jbyte*>(&string[0]));
+        return result;
+       }
    }

test/high_level.cpp

@@ -593,6 +593,23 @@ int main()
     assert(booleanArray.Length(env) == 42);
     assert(booleanArray.Get(env, 0) == jni::jni_true);
 
+    static Testable<jni::jarray<jni::jbyte>> byteArrayValue;
+
+    env.functions->GetArrayLength = [] (JNIEnv*, jarray array) -> jsize
+       {
+        assert(array == jni::Unwrap(byteArrayValue.Ptr()));
+        return 42;
+       };
+
+    env.functions->GetByteArrayRegion = [] (JNIEnv*, jbyteArray, jsize, jsize, jbyte* buf)
+       {
+        *buf = 's';
+       };
+
+    jni::Array<jni::jbyte> byteArray { byteArrayValue.Ptr() };
+    assert(byteArray.Length(env) == 42);
+    assert(byteArray.Get(env, 0) == 's');
+
 
     /// Object Array
 
@@ -746,6 +763,39 @@ int main()
     assert(jni::Make<std::vector<jboolean>>(env, jni::Make<jni::Array<jni::jboolean>>(env, vec)) == vec);
 
 
+    env.functions->NewByteArray = [] (JNIEnv*, jsize) -> jbyteArray
+       {
+        return jni::Unwrap(byteArrayValue.Ptr());
+       };
+
+    env.functions->GetArrayLength = [] (JNIEnv*, jarray array) -> jsize
+       {
+        assert(array == jni::Unwrap(byteArrayValue.Ptr()));
+        return 1;
+       };
+
+    env.functions->GetByteArrayRegion = [] (JNIEnv*, jbyteArray array, jsize start, jsize len, jbyte* buf)
+       {
+        assert(array == jni::Unwrap(byteArrayValue.Ptr()));
+        assert(start == 0);
+        assert(len == 1);
+        *buf = 's';
+       };
+
+    env.functions->SetByteArrayRegion = [] (JNIEnv*, jbyteArray array, jsize start, jsize len, const jbyte* buf)
+       {
+        assert(array == jni::Unwrap(byteArrayValue.Ptr()));
+        assert(start == 0);
+        assert(len == 1);
+        assert(*buf == 's');
+       };
+
+    std::vector<jbyte> byte_vec = { 's' };
+    assert(jni::Make<std::vector<jbyte>>(env, jni::Make<jni::Array<jni::jbyte>>(env, byte_vec)) == byte_vec);
+    std::string str("s");
+    assert(jni::Make<std::string>(env, jni::Make<jni::Array<jni::jbyte>>(env, str)) == str);
+
+
     jni::MakeNativeMethod<decltype(&Method), &Method>("name");
     jni::MakeNativeMethod<decltype(&StaticMethod), &StaticMethod>("name");