connectivity/source/inc/java/LocalRef.hxx

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  30
  31 #ifndef CONNECTIVITY_LOCALREF_HXX
  32 #define CONNECTIVITY_LOCALREF_HXX
  33
  34 /** === begin UNO includes === **/
  35 /** === end UNO includes === **/
  36
  37 #include <jvmaccess/virtualmachine.hxx>
  38
  39 //........................................................................
  40 namespace connectivity { namespace jdbc
  41 {
  42 //........................................................................
  43
  44     //====================================================================
  45     //= LocalRef
  46     //====================================================================
  47     /** helper class to hold a local ref to a JNI object
  48
  49         Note that this class never actually calls NewLocalRef. It is assumed that all objects
  50         passed are already acquired with a local ref (as it usually is the case if you obtain
  51         the object from an JNI method).
  52     */
  53     template< typename T >
  54     class LocalRef
  55     {
  56     public:
  57         explicit LocalRef( JNIEnv& environment )
  58             :m_environment( environment )
  59             ,m_object( NULL )
  60         {
  61         }
  62
  63         LocalRef( JNIEnv& environment, T object )
  64             :m_environment( environment )
  65             ,m_object( object )
  66         {
  67         }
  68
  69         ~LocalRef()
  70         {
  71             reset();
  72         }
  73
  74         T release()
  75         {
  76             T t = m_object;
  77             m_object = NULL;
  78             return t;
  79         }
  80
  81         void set( T object ) { reset(); m_object = object; }
  82
  83         void reset()
  84         {
  85             if ( m_object != NULL )
  86             {
  87                 m_environment.DeleteLocalRef( m_object );
  88                 m_object = NULL;
  89             }
  90         }
  91
  92         JNIEnv& env() const { return m_environment; }
  93         T       get() const { return m_object; }
  94         bool    is()  const { return m_object != NULL; }
  95
  96     private:
  97         LocalRef(LocalRef &); // not defined
  98         void operator =(LocalRef &); // not defined
  99
 100     protected:
 101         JNIEnv& m_environment;
 102         T       m_object;
 103     };
 104
 105 //........................................................................
 106 } } // namespace connectivity::jdbc
 107 //........................................................................
 108
 109 #endif // CONNECTIVITY_LOCALREF_HXX