切割大文件TXT

import java.io.*;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;

@Slf4j
public class SegFile {

    /**
     * 根据需求,直接调用静态方法start来执行操作 参数: rows 为多少行一个文件 int 类型 sourceFilePath 为源文件路径
     * String 类型 targetDirectoryPath 为文件分割后存放的目标目录 String 类型
     * ---分割后的文件名为源文件+'_'+索引号(从0开始)+扩展名名,例如源文件名为test.txt,则分割后文件名为test_0.txt,以此类推
     */
    public static void start(long rows, File sourceFile, File targetFile) {
        if (!sourceFile.exists() || rows <= 0 || sourceFile.isDirectory()) {
            log.info("源文件不存在或者输入了错误的行数");
            return;
        }
        if (targetFile.exists()) {
            if (!targetFile.isDirectory()) {
                log.info("目标文件夹错误,不是一个文件夹");
                return;
            }
        } else {
            targetFile.mkdirs();
        }
        long startTime = System.currentTimeMillis();
        FileInputStream in = null;
        InputStreamReader inputStreamReader=null;
        BufferedWriter bw = null;
        BufferedReader br= null;
        FileOutputStream fileOutputStream=null;
        OutputStreamWriter outputStreamWriter = null;
        try {
            in = new FileInputStream(sourceFile);
            inputStreamReader = new InputStreamReader(in, "GBK") ;
            br = new BufferedReader(inputStreamReader);
            String fullFileNm = sourceFile.getName();
            int extIndex = fullFileNm.lastIndexOf(".");
            String noExtFileNm = fullFileNm;
            String extFileNm = "";
            if (extIndex > 0) {
                noExtFileNm = fullFileNm.substring(0, extIndex);
                extFileNm = fullFileNm.substring(extIndex);
            }
            String tmpStr = "";
            String lineStr = "";
            int i = 1, fileCount = 0;
            while ((lineStr = br.readLine()) != null) {
                tmpStr += lineStr + "\r\n";
                if (i % rows == 0) {
                    File file = new File(targetFile.getAbsolutePath() + "/" + noExtFileNm + "_" + fileCount + extFileNm);
                    fileOutputStream =new FileOutputStream(file);
                    outputStreamWriter = new OutputStreamWriter(fileOutputStream, "GBK");
                    bw = new BufferedWriter(outputStreamWriter);
                    bw.write(tmpStr);
                    tmpStr = "";
                    fileCount += 1;
                    IOUtils.closeQuietly(bw);
                    log.info("{}文件分割中,分割文件为:{}",fullFileNm,file.getName());
                }
                i++;
            }
            if ((i - 1) % rows != 0) {
                File file = new File(targetFile.getAbsolutePath() + "/" + noExtFileNm + "_" + fileCount + extFileNm);
                fileOutputStream =new FileOutputStream(file);
                outputStreamWriter = new OutputStreamWriter(fileOutputStream, "GBK");
                bw = new BufferedWriter(outputStreamWriter);
                bw.write(tmpStr);
                IOUtils.closeQuietly(bw);
                IOUtils.closeQuietly(br);
                fileCount += 1;
                log.info("{}文件分割中,分割文件为:{}",fullFileNm,file.getName());
            }
            log.info("文件分割结束,共分割成了" + fileCount + "个文件");
        } catch (Exception e) {
            log.error("文件切割异常：{}",e);
        }finally {
            IOUtils.closeQuietly(in);
            IOUtils.closeQuietly(inputStreamReader);
            IOUtils.closeQuietly(fileOutputStream);
            IOUtils.closeQuietly(outputStreamWriter);
        }
        long endTime = System.currentTimeMillis();
        log.info("初次导入存量数据总耗时" + (endTime - startTime) / 1000 + "秒");
    }
}