统计年龄分布情况问题

Posted 2021-06-15 年少有为

@Slf4j
public class AgeTotal {

    public static String file = "/Desktop/age.txt";

    public static int total = 10000 * 10000;

    public static int maxAge = 180;

    public static Random random = new Random();

    public static void main(String[] args) throws Exception {
        long start = System.currentTimeMillis();
        productData();
        ageTotal();
        log.info("总用时：{}ms", System.currentTimeMillis() - start);
    }

    /**
     * 创建age文件
     *
     * @throws IOException
     */
    public static void productData() throws IOException {
        OutputStreamWriter outputStream = new OutputStreamWriter(new FileOutputStream(new File(file)), "UTF-8");
        BufferedWriter bufferedWriter = new BufferedWriter(outputStream);
        for (int i = 0; i < total; i++) {
            if (i != 0) {
                bufferedWriter.newLine();
            }
            bufferedWriter.write(random.nextInt(maxAge + 1) + "");
        }
        bufferedWriter.flush();
        bufferedWriter.close();
    }

    /**
     * 统计年龄数据分布
     *
     * @throws Exception
     */
    public static void ageTotal() throws Exception {
        int[] ageArray = new int[maxAge + 1];
        InputStreamReader inputStreamReader = new InputStreamReader(new FileInputStream(new File(file)), "UTF-8");
        BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
        String str = null;
        while ((str = bufferedReader.readLine()) != null) {
            ageArray[Integer.valueOf(str)]++;
        }
        for (int i = 0; i < ageArray.length; i++) {
            System.out.println("年龄：" + i + ",人数：" + ageArray[i]);
        }
    }

}