Question

我的代码要消耗卡夫卡，它不打印任何输出

我正在尝试通过kafka使用json消息，但未提供任何输入，这是我的输入：{“ opp_id”：“ 2”，“ opp_tenant_id”：“ 3”，“ createdWhen”：“ 4”} 我可以接收字符串反序列化器，但不能使用Jsondeserializer

非常感谢您的帮助，

ObjectMapper mapper = new ObjectMapper();

KafkaConsumer<String, JsonNode> consumer = new KafkaConsumer<String, JsonNode>(props);
    try {
    while (true) {
        ConsumerRecords<String, JsonNode> records = consumer.poll(100); 
        for (ConsumerRecord<String, JsonNode> record : records) {               
            JsonNode jsonNode = record.value();
       System.out.println(mapper.treeToValue(jsonNode,Contact.class));
        }
            }
    }

Pojo，

public class Contact {
    private String opp_id;
    private String opp_tenant_id;
    private String createdWhen;

public Contact(String opp_id,String opp_tenant_id, String createdWhen)
{
    this.opp_id =opp_id;
    this.opp_tenant_id = opp_tenant_id;
    this.createdWhen = createdWhen;

}

public void parseString(String csvStr){
    StringTokenizer st = new StringTokenizer(csvStr,",");
    opp_id = st.nextToken();
    opp_tenant_id = st.nextToken();
    createdWhen = st.nextToken();
}

public Contact() {}

public String getopp_id(){
    return opp_id;
}
public Contact setopp_id(String opp_id) {
    this.opp_id=opp_id;
    return this;
}
public String getopp_tenant_id(){
    return opp_tenant_id;
}
public Contact setopp_tenant_id(String opp_tenant_id) {
    this.opp_tenant_id=opp_tenant_id;
    return this;
}

public String getcreatedWhen(){
    return createdWhen;
}
public Contact setcreatedWhen(String createdWhen) {
    this.createdWhen=createdWhen;
    return this;
}

Answer 1

Apache kafka没有任何Error in `$<-.data.frame`(`*tmp*`, newvar, value = numeric(0)) : replacement has 0 rows, data has 139，并且apache kafka中可用的所有反序列化类均为JsonDeserializer（有关更多信息here），因此您可以使用ByteArrayDeserializer, IntegerDeserializer, LongDeserializer, StringDeserializer来读取JSON格式的消息，并使用StringDeserializer将JSON字符串转换为POJO类或者如果您想使用Object mapper，请选择Spring kafka

无法使用Kafka connect json api

1 个答案: