Add support for java.nio.Buffer

including test-suite test case and documentation

Doc/Manual/Java.html

@@ -5490,6 +5490,15 @@ These are listed below:
 <td>Use for mapping NULL terminated arrays of C strings to Java String arrays</td>
 </tr>
 
+<tr>
+<td>unsigned char *</td>
+<td>NIOBUFFER</td>
+<td>various.i</td>
+<td>input<br> output</td>
+<td>java.nio.Buffer</td>
+<td>Use for mapping directly allocated buffers to c/c++. useful with directors and long lived memory objects</td>
+</tr>
+
 </table>
 
 <H3><a name="Java_typemap_attributes"></a>25.9.6 Java typemap attributes</H3>

Examples/test-suite/java/java_lib_various_runme.java

@@ -83,6 +83,25 @@ public class java_lib_various_runme {
       if (byjove[i] != b[i])
         throw new RuntimeException("By jove, it failed: [" + new String(b) + "]");
     }
+
+    // NIOBUFFER typemap check
+      java.nio.ByteBuffer buf = java.nio.ByteBuffer.allocateDirect(10); 
+      java_lib_various.niobuffer_fill_hello(buf);
+      if (
+	(char)buf.get(0) != 'h' ||
+	(char)buf.get(1) != 'e' ||
+	(char)buf.get(2) != 'l' ||
+	(char)buf.get(3) != 'l' ||
+	(char)buf.get(4) != 'o'
+      )
+        throw new RuntimeException(
+          "nio test failed: " + 
+          (char)buf.get(0) + 
+          (char)buf.get(1) + 
+          (char)buf.get(2) + 
+          (char)buf.get(3) + 
+          (char)buf.get(4)
+        );
   }
 
 }

Examples/test-suite/java_lib_various.i

@@ -8,6 +8,7 @@
 %apply char **STRING_ARRAY { char **languages };
 %apply char *BYTE { char *chars };
 %apply char **STRING_OUT { char **string_ptr };
+%apply unsigned char *NIOBUFFER { unsigned char *buf };
 %typemap(freearg) char **languages "" // don't delete memory when setting global variable
 
 %{
@@ -47,5 +48,8 @@ void char_ptr_ptr_out(char **string_ptr) {
     *string_ptr = ret;
 }
 
+void niobuffer_fill_hello(unsigned char *buf) {
+        sprintf ((char*)buf,"hello");
+}
 %}
 

Lib/java/various.i

@@ -154,3 +154,40 @@
 /* Prevent default freearg typemap from being used */
 %typemap(freearg) char *BYTE ""
 
+/* 
+ * unsigned char *NIOBUFFER typemaps. 
+ * This is for mapping java nio buffers to c char array. it is useful for long standing pointers for callbacks
+ * and wherever performance is critical (and thus memory copy + marshaling is a burdon)
+ * Note: The Java buffer have to be allocated with allocateDirect.
+ *
+ * Example usage wrapping:
+ *   void foo(unsigned char *buf);
+ *  
+ * Java usage:
+ *   byte b[] = new byte[20]A;
+ *   java.nio.ByteBuffer b = ByteBuffer.allocateDirect(<size>); 
+ *   modulename.foo(b);
+ */
+%typemap(jni) unsigned char *NIOBUFFER "jobject"  
+%typemap(jtype) unsigned char *NIOBUFFER "java.nio.ByteBuffer"  
+%typemap(jstype) unsigned char *NIOBUFFER "java.nio.ByteBuffer"  
+%typemap(javain,
+  pre="  assert $javainput.isDirect() : \"Buffer must be allocated direct.\";") unsigned char *NIOBUFFER "$javainput"
+%typemap(javaout) unsigned char *NIOBUFFER {  
+  return $jnicall;  
+}  
+%typemap(in) unsigned char *NIOBUFFER {  
+  $1 = (unsigned char *) JCALL1(GetDirectBufferAddress, jenv, $input); 
+  if ($1 == NULL) {  
+    SWIG_JavaThrowException(jenv, SWIG_JavaRuntimeException, "Unable to get address of direct buffer. Buffer must be allocated direct.");  
+  }  
+}  
+%typemap(memberin) unsigned char *NIOBUFFER {  
+  if ($input) {  
+    $1 = $input;  
+  } else {  
+    $1 = 0;  
+  }  
+}  
+%typemap(freearg) unsigned char *NIOBUFFER ""  
+//define end