在Java中将ORC转换为JSON

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.orc.Reader;
import org.apache.orc.RecordReader;
import org.apache.orc.TypeDescription;
import org.apache.orc.mapred.OrcStruct;
import org.codehaus.jackson.map.ObjectMapper;

import java.io.IOException;

public class ORCToJSONConverter {
    public static void main(String[] args) {
        // 输入的ORC文件路径
        String orcFilePath = "path/to/input.orc";

        // 输出的JSON文件路径
        String jsonFilePath = "path/to/output.json";

        try {
            // 创建ORC文件的读取器
            Configuration conf = new Configuration();
            Reader reader = OrcFile.createReader(new Path(orcFilePath), OrcFile.readerOptions(conf));

            // 获取ORC文件的模式
            TypeDescription schema = reader.getSchema();

            // 创建JSON文件的写入器
            ObjectMapper mapper = new ObjectMapper();
            FileWriter fileWriter = new FileWriter(jsonFilePath);

            // 创建ORC文件的记录读取器
            RecordReader recordReader = reader.rows();
            OrcStruct orcStruct = null;

            // 逐行读取ORC文件，并将每行转换为JSON格式写入JSON文件
            while (recordReader.hasNext()) {
                orcStruct = (OrcStruct) recordReader.next(orcStruct);
                String json = mapper.writeValueAsString(orcStruct);
                fileWriter.write(json + "\n");
            }

            // 关闭文件读写器
            recordReader.close();
            fileWriter.close();

            System.out.println("ORC to JSON conversion completed successfully.");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}