C 如何使用librdkafka发送json数据?
我正在尝试使用librdkafka c api发送json负载。我现在想做的是C 如何使用librdkafka发送json数据?,c,json,librdkafka,jansson,C,Json,Librdkafka,Jansson,我正在尝试使用librdkafka c api发送json负载。我现在想做的是 #include <jansson.h> #include <librdkafka/rdkafka.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <time.h> typedef struct my_data { char *id;
#include <jansson.h>
#include <librdkafka/rdkafka.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
typedef struct my_data {
char *id;
char *value;
unsigned long timestamp;
} my_data;
char * my_data_to_json(const my_data *ev);
void rk_dr_callback(rd_kafka_t *rk, const rd_kafka_message_t *msg, void *opaque);
int main(int argc, char * argv[])
{
// configure producer
rd_kafka_conf_t *conf = rd_kafka_conf_new();
char errstr[512];
rd_kafka_conf_set(conf, "bootstrap.servers", "k1.example.com:9093", errstr, sizeof(errstr));
rd_kafka_conf_set_dr_msg_cb(conf, rk_dr_callback);
rd_kafka_t *rk = rd_kafka_new(RD_KAFKA_PRODUCER, conf, errstr, sizeof(errstr));
if (!rk) {
fprintf(stderr, "failed to create kafka producer: %s\n", errstr);
return -1;
}
// create json
my_data ev = {
.id = "test-id",
.value = "test-value",
.timestamp = (unsigned long) time(NULL)
};
char *json = my_data_to_json(&ev);
printf("json dump: %s\n", json);
// publish data
rd_kafka_resp_err_t err = rd_kafka_producev(rk, RD_KAFKA_V_TOPIC("topic"),
RD_KAFKA_V_MSGFLAGS(RD_KAFKA_MSG_F_COPY), RD_KAFKA_V_VALUE(json, strlen(json)),
RD_KAFKA_V_KEY("key-1", strlen("key-1")), RD_KAFKA_V_OPAQUE(NULL),
RD_KAFKA_V_END);
// cleanup
rd_kafka_flush(rk, 5 * 1000);
if (rd_kafka_outq_len(rk) > 0) {
fprintf(stderr, "%d message(s) were not delivered\n", rd_kafka_outq_len(rk));
}
rd_kafka_destroy(rk);
free(json);
return 0;
}
void rk_dr_callback(rd_kafka_t *rk, const rd_kafka_message_t *msg, void *opaque)
{
if (msg->err) {
printf("failed to send message: %s\n", rd_kafka_err2str(msg->err));
}
else {
printf("delivered %zd bytes to partition %d\n", msg->len, msg->partition);
}
}
char * my_data_to_json(const my_data *ev)
{
/* build the JSON object {"id": "id", "value": "value", "timestamp": 12345678} */
json_t *json = json_pack("{sssssi}", "id", ev->id, "value", ev->value, "timestamp", ev->timestamp);
if (!json) {
fprintf(stderr, "failed to construct json from data\n");
}
char *str = json_dumps(json, JSON_COMPACT);
if (!str) {
fprintf(stderr, "failed to encode json object\n");
}
return str;
}
我不太清楚我的错误是在构造json对象、将其编码为字符串还是在使用librdkafka发布json字符串的方式上。“我不太清楚我的错误是在构造json对象、将其编码为字符串还是在使用librdkafka发布json字符串的方式上”-然后,您应该将这三种代码分别隔离开来,看看哪一种出错了。如果您在创建或编码JSON时遇到错误,您只是在记录错误。我认为如果这些步骤中的任何一个失败,您应该返回一个
NULL
字符串,并检查调用函数main()
是否my_data\u to_json
返回NULL
。此外,您是否能够看到在发布端(C端)记录的任何错误消息?@kiner_shah我可以看到发送到代理的字节数不为零,并且发布服务器端没有错误。我想知道json的编码是否有问题,因为它需要utf-8,而我没有做任何事情来确保它是utf-8。我现在正在仔细阅读。
Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing value: . Path '', line 0, position 0.\n at Newtonsoft.Json.JsonTextReader.ParseValue()\n at ...