我建立了一个c函数，该函数应该通过stomp库从ActiveMQ中读取。此代码在RECEIPT之前读取了其他MESSAGE（这是我所期望的）。请告知为什么第二个MESSAGE帧之前我的RECEIPT帧不出现。另外请注意，我将此代码包装在BEGIN和COMMIT框架中，这可能是最佳实践，也可能不是最佳实践。
谢谢。
int receive_from_queue_ack( MQDEF *mqdef, int transaction ) {
apr_status_t rc;
stomp_frame frame_write;
stomp_frame* frame_read = NULL;
char transaction_str[37];
char* ack = NULL;
char* protocol = NULL;
char* receipt_id = NULL;
char* message_id = NULL;
char* message = NULL;
char* seq = NULL;
uuid_t uuid;
char receipt_id_begin_uuid[37];
char receipt_id_commit_uuid[37];
char receipt_id_ack_uuid[37];
char id_uuid[37];
int receipt_flag = 1;
uuid_generate_random(uuid);
uuid_unparse_lower(uuid, transaction_str);
uuid_generate_random(uuid);
uuid_unparse_lower(uuid, receipt_id_begin_uuid);
uuid_generate_random(uuid);
uuid_unparse_lower(uuid, id_uuid);
uuid_generate_random(uuid);
uuid_unparse_lower(uuid, receipt_id_commit_uuid);
uuid_generate_random(uuid);
uuid_unparse_lower(uuid, receipt_id_ack_uuid);
fprintf(stdout, "1) *** Transaction BEGIN - (receive_from_queue)\n");
frame_write.command = "BEGIN";
frame_write.headers = apr_hash_make((apr_pool_t *)mqdef->pool);
apr_hash_set(frame_write.headers, "transaction", APR_HASH_KEY_STRING, transaction_str);
frame_write.body_length = -1;
frame_write.body = NULL;
rc = stomp_write(mqdef->amqConnection, &frame_write, (apr_pool_t *)mqdef->pool);
if ( rc != APR_SUCCESS ) {
return FAILURE;
}
printf("3) Subscribe begin\n");
frame_write.command = "SUBSCRIBE";
frame_write.headers = apr_hash_make((apr_pool_t *)mqdef->pool);
apr_hash_set(frame_write.headers, "destination", APR_HASH_KEY_STRING, mqdef->queueName);
apr_hash_set(frame_write.headers, "ack", APR_HASH_KEY_STRING, "client");
apr_hash_set(frame_write.headers, "id", APR_HASH_KEY_STRING, "client-123");
apr_hash_set(frame_write.headers, "activemq.prefetchSize", APR_HASH_KEY_STRING, "1");
frame_write.body_length = -1;
frame_write.body = NULL;
rc = stomp_write(mqdef->amqConnection, &frame_write, (apr_pool_t *)mqdef->pool);
if ( rc != APR_SUCCESS ) {
return FAILURE;
}
frame_read = NULL;
rc = stomp_read(mqdef->amqConnection, &frame_read, (apr_pool_t *)mqdef->pool);
if ( rc != APR_SUCCESS ) {
return FAILURE;
}
ack = NULL;
if( frame_read != NULL && strncmp(frame_read->command, "MESSAGE", 7) == 0 ) {
ack = (char*) apr_hash_get(frame_read->headers, "ack", APR_HASH_KEY_STRING);
printf("5) ack=<%s>\n", ack);
if( ack == NULL ) {
printf("ack being null is a problem\n");
exit(1);
}
message_id = (char*) apr_hash_get(frame_read->headers, "message-id", APR_HASH_KEY_STRING);
printf("5) message_id=<%s>\n", message_id);
printf("5) command=<%s>, body=<%s>\n", frame_read->command, frame_read->body);
} else if( frame_read != NULL && strncmp(frame_read->command, "ERROR", 5) == 0 ) {
message_id = (char*) apr_hash_get(frame_read->headers, "message-id", APR_HASH_KEY_STRING);
printf("5) message_id=<%s>\n", message_id);
printf("5) command=<%s>, body=<%s>\n", frame_read->command, frame_read->body);
exit(1);
} else {
message_id = (char*) apr_hash_get(frame_read->headers, "message-id", APR_HASH_KEY_STRING);
printf("5) message_id=<%s>\n", message_id);
printf("5) command=<%s>, body=<%s>\n", frame_read->command, frame_read->body);
printf("5) should never get here.\n");
exit(1);
}
frame_write.command = "ACK";
frame_write.headers = apr_hash_make((apr_pool_t *)mqdef->pool);
apr_hash_set(frame_write.headers, "transaction", APR_HASH_KEY_STRING, transaction_str);
apr_hash_set(frame_write.headers, "id", APR_HASH_KEY_STRING, ack);
apr_hash_set(frame_write.headers, "receipt-id", APR_HASH_KEY_STRING, receipt_id_ack_uuid);
printf("set id =<%s>\n", ack);
frame_write.body_length = -1;
frame_write.body = NULL;
rc = stomp_write(mqdef->amqConnection, &frame_write, (apr_pool_t *)mqdef->pool);
if ( rc != APR_SUCCESS ) {
return FAILURE;
}
frame_read = NULL;
rc = stomp_read(mqdef->amqConnection, &frame_read, (apr_pool_t *)mqdef->pool);
if ( rc != APR_SUCCESS ) {
return FAILURE;
}
if( frame_read != NULL && strncmp(frame_read->command, "RECEIPT", 7) == 0 ) {
message_id = (char*) apr_hash_get(frame_read->headers, "message-id", APR_HASH_KEY_STRING);
receipt_id = (char*) apr_hash_get(frame_read->headers, "receipt-id", APR_HASH_KEY_STRING);
printf("7) receipt-id=<%s>\n", receipt_id);
printf("7) message-id=<%s>\n", message_id);
printf("7) command=<%s>, body=<%s>\n", frame_read->command, frame_read->body);
} else if( frame_read != NULL && strncmp(frame_read->command, "ERROR", 5) == 0 ) {
message_id = (char*) apr_hash_get(frame_read->headers, "message_id", APR_HASH_KEY_STRING);
receipt_id = (char*) apr_hash_get(frame_read->headers, "receipt-id", APR_HASH_KEY_STRING);
printf("7) receipt-id=<%s>\n", receipt_id);
printf("7) message-id=<%s>\n", message_id);
printf("7) command=<%s>, body=<%s>\n", frame_read->command, frame_read->body);
exit(1);
} else {
message_id = (char*) apr_hash_get(frame_read->headers, "message_id", APR_HASH_KEY_STRING);
printf("7) message-id=<%s>\n", message_id);
printf("7) command=<%s>, body=<%s>\n", frame_read->command, frame_read->body);
ack = (char*) apr_hash_get(frame_read->headers, "ack", APR_HASH_KEY_STRING);
printf("5) ack=<%s>\n", ack);
printf("this is a failure\n");
frame_write.command = "ACK";
frame_write.headers = apr_hash_make((apr_pool_t *)mqdef->pool);
apr_hash_set(frame_write.headers, "transaction", APR_HASH_KEY_STRING, transaction_str);
apr_hash_set(frame_write.headers, "id", APR_HASH_KEY_STRING, ack);
apr_hash_set(frame_write.headers, "receipt-id", APR_HASH_KEY_STRING, receipt_id_ack_uuid);
rc = stomp_write(mqdef->amqConnection, &frame_write, (apr_pool_t *)mqdef->pool);
if ( rc != APR_SUCCESS ) {
return FAILURE;
}
}
frame_write.command = "COMMIT";
frame_write.headers = apr_hash_make((apr_pool_t *)mqdef->pool);
apr_hash_set(frame_write.headers, "transaction", APR_HASH_KEY_STRING, transaction_str);
frame_write.body_length = -1;
frame_write.body = NULL;
rc = stomp_write(mqdef->amqConnection, &frame_write, (apr_pool_t *)mqdef->pool);
if ( rc != APR_SUCCESS ) {
return FAILURE;
}
fprintf(stdout, "12) *** Transaction Complete - (receive_from_queue)\n\n");
}
答案 0 :(得分：1)
您没有在确认中使用正确的STOMP标头来指示ACK ID，因此代理告诉您您做错了。 STOMP规范是一个开始学习在每个表演中添加内容的好地方，在这种情况下，标头是“ id”而不是“ message-id”
像往常一样，对于C代码来说，很难阅读，因此使用一些注释或上下文在上面重新编写代码会有所帮助，但到目前为止，我还没有看到客户端代码从传入消息中获取“ ack”标头的位置，并且将其传输到实际的“ ACK”帧，因此可能是问题所在。
根据规格：
如果从需要显式确认的订阅（客户端或客户端个人模式）接收到消息，则MESSAGE帧还必须包含带有任意值的ack头。此标头将用于将消息与后续的ACK或NACK帧相关。
请参阅STOMP specification以了解更多信息