java - StringRedisTemplate如何使用redis zcard方法？

Question

如何在下面的程序中正确使用 StringRedisTemplate 方法？

public void put(StringRedisTemplate template, final Object key, final Object value ) {
    template.execute(new RedisCallback<Object>() {
        public Object doInRedis(RedisConnection connection) throws DataAccessException {
             connection.zCard((byte[]) key);

             connection.exec();
             return null;
        }

     }
    );
}

Answer 1

您可以像这样在 RedisConnection 上调用 zCard(key):

Long zCard = template.execute(new RedisCallback<Long>() {

  @Override
  public Long doInRedis(RedisConnection connection) throws DataAccessException {
    return connection.zCard(potentiallyExtractBytes(key));
  }

  private byte[] potentiallyExtractBytes(Object key) {
    return (key instanceof byte[]) ? (byte[]) key : key.toString().getBytes();
  }

});