我正在尝试使用MySQL表中的记录,该表包含3列(Axis, Price, lastname)
,其数据类型分别为(int, decimal(14,4), varchar(50))
。
我插入了一条记录,其中包含以下数据(1, 5.0000, John)
。
以下Java代码(使用Confluent平台中MySQL Connector创建的主题中的AVRO记录)读取十进制列:Price,作为java.nio.HeapByteBuffer类型,因此当我收到时,我无法达到列的值它。
有没有办法将接收的数据提取或转换为Java十进制或双数据类型?
这是MySQL Connector属性文件: -
{
"name": "mysql-source",
"config": {
"connector.class": "io.confluent.connect.jdbc.JdbcSourceConnector",
"key.converter": "io.confluent.connect.avro.AvroConverter",
"key.converter.schema.registry.url": "http://localhost:8081",
"value.converter": "io.confluent.connect.avro.AvroConverter",
"value.converter.schema.registry.url": "http://localhost:8081",
"incrementing.column.name": "Axis",
"tasks.max": "1",
"table.whitelist": "ticket",
"mode": "incrementing",
"topic.prefix": "mysql-",
"name": "mysql-source",
"validate.non.null": "false",
"connection.url": "jdbc:mysql://localhost:3306/ticket?
user=user&password=password"
}
}
这是代码: -
public static void main(String[] args) throws InterruptedException,
IOException {
Properties props = new Properties();
props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
props.put(ConsumerConfig.GROUP_ID_CONFIG, "group1");
props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,
"org.apache.kafka.common.serialization.StringDeserializer");
props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,
"io.confluent.kafka.serializers.KafkaAvroDeserializer");
props.put("schema.registry.url", "http://localhost:8081");
props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
String topic = "sql-ticket";
final Consumer<String, GenericRecord> consumer = new KafkaConsumer<String, GenericRecord>(props);
consumer.subscribe(Arrays.asList(topic));
try {
while (true) {
ConsumerRecords<String, GenericRecord> records = consumer.poll(100);
for (ConsumerRecord<String, GenericRecord> record : records) {
System.out.printf("value = %s \n", record.value().get("Price"));
}
}
} finally {
consumer.close();
}
}
好吧,所以我终于找到了解决方案。
Heapbytebuffer
需要转换为byte[]
数组,然后我使用BigInteger
构造从创建的字节数组中的值,然后我创建了一个BigDecimal
变量,它接受BigInteger的值,我用movePointLeft(4)
设置小数点,这是规模(在我的情况下:4)一切都按预期工作。
ByteBuffer buf = (ByteBuffer) record.value().get(("Price"));
byte[] arr = new byte[buf.remaining()];
buf.get(arr);
BigInteger bi =new BigInteger(1,arr);
BigDecimal bd = new BigDecimal(bi).movePointLeft(4);
System.out.println(bd);
结果如下(左边是输出,右边是MySQL): -