如何在Java中将CSV文件逐行拆分成不同的CSV文件？

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class CSVSplitter {
    public static void main(String[] args) {
        String inputFile = "input.csv"; // 原始CSV文件路径
        String outputDirectory = "output/"; // 拆分后的CSV文件存储目录

        try (BufferedReader reader = new BufferedReader(new FileReader(inputFile))) {
            String line;
            Map<String, BufferedWriter> writers = new HashMap<>();

            while ((line = reader.readLine()) != null) {
                String[] columns = line.split(","); // 假设CSV文件以逗号分隔

                // 根据特定列值进行拆分，这里假设拆分条件是第一列的值
                String splitValue = columns[0];

                BufferedWriter writer = writers.get(splitValue);
                if (writer == null) {
                    String outputFile = outputDirectory + splitValue + ".csv";
                    writer = new BufferedWriter(new FileWriter(outputFile));
                    writers.put(splitValue, writer);
                }

                writer.write(line);
                writer.newLine();
            }

            // 关闭所有的文件写入器
            for (BufferedWriter writer : writers.values()) {
                writer.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}