Java 按行切割文件

最近公司项目需要把一个大文件按行分割为若干个小文件，对每一个小文件进行单独处理，以提高效率。

SplitFileTest.Java

import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.OutputStreamWriter;/** * 按行分割文件 工具类 * @author FX_SKY * */public class SplitFileTest {/** * @param args */public static void main(String[] args) {test();}private static void test() {int startRowNumber = 0;int rowNumberSize = 60000;String dirPath = "D:/fbb/myWorkSpacev_GanJiC/FinalDB/";String sourceFileName = "201348-feng-v001ganjicom";for(int i=0;i<11;i++){startRowNumber = i*rowNumberSize;splitFile(startRowNumber,rowNumberSize,dirPath,sourceFileName);}}/** * 从指定行数 startRowNumber起，截取 rowNumberSize 行保存到一个单独的文件，命名为 sourceFileName_1.后缀名 * @param startRowNumber * @param rowNumberSize * @param dirPath * @param sourceFileName  */public static void splitFile(int startRowNumber, int rowNumberSize,String dirPath, String sourceFileName) {File inputFile = new File(dirPath+sourceFileName);if(inputFile==null || !inputFile.exists()){throw new RuntimeException("待处理的数据文件不存在,文件路径:"+inputFile.getAbsolutePath());}System.out.println("开始分割文件  "+sourceFileName);String suffix = "";String realFileName = sourceFileName;int index = sourceFileName.lastIndexOf(".");if(index>0){//abc.txtsuffix = sourceFileName.substring(index, sourceFileName.length());//.txtrealFileName = sourceFileName.substring(0, sourceFileName.lastIndexOf("."));//abc}int serilizeNumber = 1;String outputPath = dirPath+realFileName+"_"+serilizeNumber + suffix;File outputFile = new File(outputPath);while(outputFile.exists()){//判断分割后的文件是否已经存在serilizeNumber++;outputPath = dirPath+realFileName+"_"+serilizeNumber + suffix;outputFile = new File(outputPath);}System.out.println("分割后的文件 "+outputPath);int currentIndex = 0;//当前的行数int writeNumber = 0;//已经写出的行数InputStream in = null;InputStreamReader reader = null;BufferedReader br = null;OutputStream out = null;OutputStreamWriter writer = null;BufferedWriter bw = null;try {in = new FileInputStream(inputFile);reader = new InputStreamReader(in,"utf-8");//指定编码br = new BufferedReader(reader);//写出out = new FileOutputStream(outputFile);writer = new OutputStreamWriter(out, "utf-8");bw = new BufferedWriter(writer);String line = null;String newLine = null;while((line=br.readLine())!=null){currentIndex++;if(writeNumber>=rowNumberSize){break;}if(currentIndex>=startRowNumber){newLine = line;bw.write(newLine);bw.newLine();writeNumber++;}}bw.flush();System.out.println("分割文件完成...");}catch (Exception e) {e.printStackTrace();}finally{try {br.close();} catch (IOException e) {e.printStackTrace();}try {bw.close();} catch (IOException e) {e.printStackTrace();}}}}