java - 如何从缓冲读取器读取前五个字符？

Question

我有这个代码

Process p =Runtime.getRuntime().exec("busybox");
        InputStream a = p.getInputStream();
        InputStreamReader read = new InputStreamReader(a);
        BufferedReader in = new BufferedReader(read);

从终端运行它，oupout 的第一行返回 Busybox 的版本。如果我想像我一样以前 5 个字符为例？

Answer 1

虽然其他答案也应该很好地工作，但以下内容将在读取五个字符后退出并关闭流:

    Process p = Runtime.getRuntime().exec("busybox");
    InputStream a = p.getInputStream();
    InputStreamReader read = new InputStreamReader(a);

    StringBuilder firstFiveChars = new StringBuilder();

    int ch = read.read();

    while (ch != -1 && firstFiveChars.length() < 5) {
        firstFiveChars.append((char)ch);
        ch = read.read();
    }

    read.close();
    a.close();

    System.out.println(firstFiveChars);