mpd/src/java/Class.hxx

/*
 * Copyright 2010-2018 Max Kellermann <max.kellermann@gmail.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the
 * distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef JAVA_CLASS_HXX
#define JAVA_CLASS_HXX

#include "Ref.hxx"
#include "Exception.hxx"

#include <cassert>

namespace Java {
	/**
	 * Wrapper for a local "jclass" reference.
	 */
	class Class : public LocalRef<jclass> {
	public:
		Class(JNIEnv *env, jclass cls) noexcept
			:LocalRef<jclass>(env, cls) {}

		Class(JNIEnv *env, const char *name) noexcept
			:LocalRef<jclass>(env, env->FindClass(name)) {}
	};

	/**
	 * Wrapper for a global "jclass" reference.
	 */
	class TrivialClass : public TrivialRef<jclass> {
	public:
		void Find(JNIEnv *env, const char *name) noexcept {
			assert(env != nullptr);
			assert(name != nullptr);

			jclass cls = env->FindClass(name);
			assert(cls != nullptr);

			Set(env, cls);
			env->DeleteLocalRef(cls);
		}

		bool FindOptional(JNIEnv *env, const char *name) noexcept {
			assert(env != nullptr);
			assert(name != nullptr);

			jclass cls = env->FindClass(name);
			if (DiscardException(env))
				return false;

			Set(env, cls);
			env->DeleteLocalRef(cls);
			return true;
		}
	};
}

#endif