针对Java中的大型输入优化BufferedReader

Question

我正在尝试使用以下代码从标准输入中读取一行大约200万个字符的行：

BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
s = in.readLine();

对于上述输入， s = in.readLine(); 行需要30分钟以上才能执行。

有没有读取此输入的更快方法？

Answer 1

不要尝试逐行读取，而是尝试读取字符缓冲区

试试这个

BufferedInputStream in = null;
try {
    in = new BufferedInputStream(new FileInputStream("your-file"));

    byte[] data = new byte[1024];
    int count = 0;

    while ((count = in.read(data)) != -1) {
      // do what you want - save to other file, use a StringBuilder, it's your choice
    }
} catch (IOException ex1) {
  // Handle if something goes wrong
} finally {
    if (in != null) {
      try {
        in.close();
      } catch (IOException ) {
        // Handle if something goes wrong
      }
    }
}