Question

This method blocks until at least one byte of input is avail

Answer 1

ead()

public int read(byte[] b)

throws IOException 抛出异常

Reads up to b.length bytes of data from this file into an array of bytes.This method blocks until at least one byte of input is available.从此文件读入b长度字节数据到数组中.

没有哪怕一个字节的输入可用,该函数就一直阻塞下去.（至少有1个字节的输入才能继续执行）.