MapReduce服务 MRS-IoTDB自定义函数(UDF)样例程序:代码样例

时间:2025-02-12 15:00:30

代码样例

以下为代码片段示例:

package com.huawei.bigdata.iotdb;import org.apache.iotdb.udf.api.UDTF;import org.apache.iotdb.udf.api.access.Row;import org.apache.iotdb.udf.api.collector.PointCollector;import org.apache.iotdb.udf.api.customizer.config.UDTFConfigurations;import org.apache.iotdb.udf.api.customizer.parameter.UDFParameters;import org.apache.iotdb.udf.api.customizer.strategy.RowByRowAccessStrategy;import org.apache.iotdb.udf.api.type.Type;import java.io.IOException;public class UDTFExample implements UDTF {    @Override         public void beforeStart(UDFParameters parameters, UDTFConfigurations configurations) {               configurations.setAccessStrategy(new RowByRowAccessStrategy()).setOutputDataType(Type.INT32);        }    @Override        public void transform(Row row, PointCollector collector) throws IOException {              collector.putInt(row.getTime(), -row.getInt(0));        }}
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