文件逐行写入BufferedWriter的刷新flush()方法

package src.readFile;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;

public class ReadFile { 
    public static void main(String[] args) { 
        try {
            //已使用的最大卡号
            int MAXCARDNO = 497895;
            //int MAXCARDNO = 10;
            //已使用卡号最大条数
            int COUNTCARDNO = 119039;
            //int COUNTCARDNO = 3;
            Scanner in = new Scanner(new File("d:"+File.separator+"cardno.txt"));
            //初始化读入文件数据个数
            long[] inputArr = new long[COUNTCARDNO];
            int i = 0;

            System.out.println("读入文件内容：");
            while (in.hasNextLine()) { 
                String str = in.nextLine();
                str = str.substring(5);
                Long intTemp = Long.parseLong(str.trim());
                //splitt(str); 
//                System.out.println(intTemp);
                inputArr[i++]=intTemp;
            } 
            
            String[] outputArr = new String[60000];
            String cardNoTemp = "";
            //未使用的卡号循环记录
            int abak = 1;
            //未使用的卡号数组下标记录
            int outI = 0;
            
            //输出文件生成
            String filePath1 = "D:"+File.separator+"output.txt";
            try {
                FileWriter fw = new FileWriter(filePath1);
                BufferedWriter bw = new BufferedWriter(fw);
            
                System.out.println("未使用卡号如下：");
                for (int inputI=0;inputI<COUNTCARDNO;inputI++) {
                    for (int a=abak; a<=MAXCARDNO; a++) {
                           if (a==inputArr[inputI]) {
                               abak=++a;
                            break;
                        } else {
                            cardNoTemp = "04003" + codeAddZero(String.valueOf(a), 9);
                            outputArr[outI++] = cardNoTemp;
                            bw.write(cardNoTemp);
                            bw.newLine(); 
                            System.out.println("没有使用的cardNo：" + cardNoTemp);
                        }
                    }
                }
                bw.flush();
                bw.close();
                fw.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } 
        } catch (FileNotFoundException e) { 
            e.printStackTrace(); 
        } 
    } 

    /**
     * 卡号自动前补零操作
     * @param code
     * @param len
     * @return
     */
    public static String codeAddZero(String code, int len){
        String strCode = code;
        while (strCode.length() < len) {
            strCode = "0" + strCode;
         }
        return strCode;
     }
}