Java Transaction.incr方法代码示例

import redis.clients.jedis.Transaction; //导入方法依赖的package包/类
public static void main(String[] args) throws InterruptedException {
	ApplicationContext ac = new ClassPathXmlApplicationContext("root-context.xml");
	JedisPool pool = (JedisPool) ac.getBean("jedisPool");
	int count = 0;
	while (true) {
		Jedis jedis = pool.getResource();
		jedis.get("keyName");
		Transaction tx = jedis.multi();
		tx.incr("keyName");
		tx.expire("keyName", 10);
		tx.exec();	
		jedis.close();
		System.out.println("jedisPool active count:" + pool.getNumActive());
		System.out.println("jedisPool idle count:" + pool.getNumIdle());
		Thread.sleep(10);
	}

}
 

import redis.clients.jedis.Transaction; //导入方法依赖的package包/类
/**
 * This method takes a RedisMessage and pushes it onto the topic specified by the message.
 *
 * @param message message to push onto RedisMQ
 */
public void send(RedisMessage message) throws IOException {
    Preconditions.checkNotNull(message);
    List<Object> result = null;
    int tries = 0;
    String topic = message.getTopic();
    String nextIndexKey = RedisMQUtils.getNextIndexForTopicKey(topic);
    long nextIndex = 1;

    // Only try sending three times. The result object will not be null if the exec() command
    // succeeds.
    while ((result == null || result.size() == 0) && tries < 3) {
        if (jedis.exists(nextIndexKey)) {
            nextIndex = Long.parseLong(RedisMQUtils.jedisGetString(jedis, nextIndexKey)) + 1;
        }
        String messageKey = RedisMQUtils.getMessageKey(topic, Long.toString(nextIndex));

        // If the nextIndexKey or messageKey change then the transaction should fail
        jedis.watch(nextIndexKey, messageKey);
        Transaction t = jedis.multi();
        t.incr(nextIndexKey);
        t.set(messageKey.getBytes(), message.getPayload());
        result = t.exec();
        tries++;
    }

    if (result == null || result.size() == 0) {
        throw new RuntimeException("Attempted to send 3 times. Could not obtain lock.");
    }
}
 

import redis.clients.jedis.Transaction; //导入方法依赖的package包/类
/**
 * This method polls the given topic for a message. Optional.absent() is returned when no new message is found.
 *
 * @param topic the topic to poll for a message
 * @return the retrieved message
 */
public Optional<byte[]> poll(String topic) throws IOException {
    Preconditions.checkArgument(!Strings.isNullOrEmpty(topic));
    Optional<byte[]> result = Optional.absent();
    String currentIndexKey = RedisMQUtils.getNextIndexForTopicKey(topic);

    long endMillis = System.currentTimeMillis() + timeout;

    // Continue to poll the queue until the timeout period ends
    while (System.currentTimeMillis() < endMillis) {
        // If the current index does not exist, then the topic does not exist
        if (jedis.exists(currentIndexKey)) {
            long currentIndex = Long.parseLong(RedisMQUtils.jedisGetString(jedis, currentIndexKey));
            String consumerIndexKey = RedisMQUtils.getNextIndexForGroupIdKey(topic, groupId);

            // Watch the consumer index to make sure that we don't increment twice when only looking for one
            // message
            jedis.watch(consumerIndexKey);
            long consumerIndex = 0;
            if (jedis.exists(consumerIndexKey)) {
                consumerIndex = Long.parseLong(RedisMQUtils.jedisGetString(jedis, consumerIndexKey));
            }

            // Check to make sure the current message index is higher than the group index, signifying that there
            // are new messages on the queue
            if (currentIndex > consumerIndex) {
                Transaction t = jedis.multi();
                t.incr(consumerIndexKey);
                List<Object> execResult = t.exec();

                // If the transaction succeeded it means that the key was incremented and we can consume a message
                if (execResult != null && execResult.size() > 0) {
                    consumerIndex = (Long)execResult.get(0);
                    String key = RedisMQUtils.getMessageKey(topic, Long.toString(consumerIndex));
                    byte[] keyBytes = key.getBytes();
                    if (jedis.exists(keyBytes)) {
                        byte[] payload = RedisMQUtils.jedisGetBytes(jedis, keyBytes);
                        result = Optional.of(payload);
                        break;
                    }
                }
            }
        }
    }

    return result;
}