Java学习--随机点名器（读取本地文件）（4种点名方式）

 

 

 

 随机点名器（读取本地文件）（4种点名方式）

思路：读取本地文件

           存入集合

           第一种直接随机读取

            第二种加权

            第三种创一个文件计数

                第四种通过编写刷新代码

public class RandomRollCall {
    public static void main(String[] args) throws IOException {
        //RandomRollCall1();
        //RandomRollCall2();
        //RandomRollCall3();
        RandomRollCall4();

    }
    private static void RandomRollCall4() throws IOException {
        //创建集合存入读取内容
        ArrayList<String> list = new ArrayList<>();
        //一行一行读取文件信息
        BufferedReader br = new BufferedReader(new FileReader("src\\MyUrl\\information.txt"));
        String line;
        while (true){
            //判断文件是否为空
            if ((line= br.readLine())!=null){
                list.add(line.split("-")[0]);
            }else if (list.size()==0){
                //为空重新生成
                refresh.re();
            }else {
                break;
            }
        }
        br.close();
        Random r =new Random();
        int i = r.nextInt(list.size());
        System.out.println(list.remove(i));

    }

    private static void RandomRollCall3() throws IOException {
        //读取计数器文件
        BufferedReader br = new BufferedReader(new FileReader("src\\MyUrl\\count.txt"));
        String line;
        line= br.readLine();
        br.close();
        //计数器文件计数+1
        FileWriter fw = new FileWriter("src\\MyUrl\\count.txt");
        fw.write(Integer.parseInt(line)+1+"");
        fw.close();
        //此次若是3的倍数，输出张三
        if ((Integer.parseInt(line)+1)%3==0){
            System.out.println("张三");
            return;
        }
        RandomRollCall1();
    }

    private static void RandomRollCall2() throws IOException {
        //创建集合存入读取内容
        ArrayList<String> nanList = new ArrayList<>();
        ArrayList<String> nvList = new ArrayList<>();
        //一行一行读取文件信息
        BufferedReader br = new BufferedReader(new FileReader("src\\MyUrl\\information.txt"));
        String line;
        while ((line= br.readLine())!=null){
            String[] split = line.split("-");
            if (split[1].equals("男")){
                nanList.add(split[0]);
            }else if (split[1].equals("女")){
                nvList.add(split[0]);
            }else {
                System.out.println(line);
            }
            /*switch (split[1]){
                case "男":
                    nanList.add(split[0]);
                case "女":
                    nvList.add(split[0]);
                default:
                    System.out.println(line);
            }*/
        }
        br.close();
        Random r = new Random();
        //加权
        if (r.nextInt(10)<3){
            System.out.println(nvList.get(r.nextInt(nvList.size())));
        }else {
            System.out.println(nanList.get(r.nextInt(nanList.size())));
        }
        //此为测试比率是否为7：3
        /*int count1=0;
        int count2=0;
        for (int i = 0; i < 10000000; i++) {
            int j = r.nextInt(10);
            if (j<3){
                count1++;
            }else {
                count2++;
            }
        }
        System.out.println(count1+","+count2);*/
    }

    private static void RandomRollCall1() throws IOException {
        //创建集合存入读取内容
        ArrayList<String> list = new ArrayList<>();
        //一行一行读取文件信息
        BufferedReader br = new BufferedReader(new FileReader("src\\MyUrl\\information.txt"));
        String line;
        while ((line= br.readLine())!=null){
            list.add(line.split("-")[0]);
        }
        br.close();
        Random r =new Random();
        System.out.println(list.get(r.nextInt(list.size())));
    }
}

第四中点名方式中的刷新文件内容在上一篇文章

https://blog.youkuaiyun.com/m0_73856491/article/details/129208291