• [实例]JAVA生成字母+随机数字并生成文件


    package com.ishow.control.code;
    
    import java.io.*;
    import java.text.SimpleDateFormat;
    import java.util.Random;
    
    /**
     * @author Lee
     * @version 创建时间:Oct 9, 2015 4:12:25 PM
     */        
    public class CreateCodeController{
        /**
         * 生成兑换码
         * @return
         * @throws IOException 
         */
        public static void main(String[] args){
            
            Long start = System.currentTimeMillis();
            
            String prefix = "LF";    //前缀
             int num = 10;//数字位数
             int count = 10000;//生成数量
    
             SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH时mm分");
            
            //生成文件地址
             File f = new File("C:\Documents and Settings\Administrator\桌面\生成码" + formatter.format(System.currentTimeMillis()) + ".txt");
            
            OutputStreamWriter writer = null;
            BufferedWriter bw = null;
            
            Random random = new Random();
            try {
                OutputStream os = new FileOutputStream(f);
                writer = new OutputStreamWriter(os);
                bw = new BufferedWriter(writer);
                int i=0;
                while(i<count){
                    String str = "";
                    for (int j = 0; j < num; j++) {
                        int number = random.nextInt(10);      
                        str+=number+"";
                    }
                    str = prefix+str;
                    try {
                        bw.write(str+"
    ");
                    } catch (Exception e) {
                        i--;
                    }
                  i++;
                }
                bw.flush();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    bw.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            Long end = System.currentTimeMillis();
            System.out.println("bufferedWrite And FileWriterTest's time---------" + (start - end)/1000d);
        }
    }


     

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  • 原文地址:https://www.cnblogs.com/xiaocaocao/p/4882707.html
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