IO流切割过大文件代码

先查出总行数，之后再以总行数分割文件
import java.io.*;
public class GetRows {

    public static void main(String args[]) {
        try {
            FileReader read = new FileReader("D:/解绑记录.csv");
            BufferedReader br = new BufferedReader(read);
            String row;

            int rownum = 1;
            while ((row = br.readLine()) != null) {
                rownum ++;
            }
            System.out.println("rownum="+rownum);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

开始分割文件，注意 readline方法是自动换行；
import java.io.*;
public class CutFile {

    public static void main(String args[]) {
        try {
            FileReader read = new FileReader("D:/解绑记录.csv");
            BufferedReader br = new BufferedReader(read);
            String row;

            int rownum = 1;

            int fileNo = 1;
            FileWriter fw = new FileWriter("D:/解绑记录"+fileNo +".csv");
            String rowOne = br.readLine();  //由于每个切割文件都需要记录第一行标题，这边将它记录下来，，
            fw.append(rowOne + "\r\n");
            while ((row = br.readLine()) != null) {
                rownum ++;
                fw.append(row + "\r\n");

                if((rownum / 156566) > (fileNo - 1)){
                    fw.close();
                    fileNo ++ ;
                    fw = new FileWriter("D:/解绑记录"+fileNo +".csv");
                    fw.append(rowOne + "\r\n");
                }
            }
            fw.close();
            System.out.println("rownum="+rownum+";fileNo="+fileNo);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}