输入 Streams.read() 究竟是如何工作的呢？

Question

我有以下代码：

public static void main(String[] args) throws Exception {

 FileInputStream inputStream = new FileInputStream("c:/data.txt");

 FileOutputStream outputStream = new FileOutputStream("c:/result.txt");

 while (inputStream.available() > 0) {
  int data = inputStream.read(); 
  outputStream.write(data); 
 }

 inputStream.close(); 
 outputStream.close();
}

我不明白下面这行： int data = inputStream.read();

获取文件c:/data.txt的字节，逐字节读取，然后在可变数据中自动拼接或者inputStream.read()读取文件c:/data.txt全部立即将所有内容分配给数据变量？

Answer 1

来自 JavaDoc:

A FileInputStream 从文件系统中的文件获取输入字节。 FileInputStream 用于 读取原始字节流，例如图像数据 。要读取 字符流 ，请考虑使用 FileReader

Question: Get the bytes of the file c:/data.txt, read byte by byte, and then get concatenated automatically within the variable data or does inputStream.read() read the file c:/data.txt all at once and assign everything to the data variable?

为了回答这个问题，让我们举个例子：

try {
  FileInputStream fin = new FileInputStream("c:/data.txt");
  int i = fin.read();
  System.out.print((char) i);
  fin.close();
} catch (Exception e) {
  System.out.println(e);
}

在运行上述程序之前创建了一个 data.txt 文件，其中包含以下文本：Welcome to Whosebug.

After the execution of above program the console prints single character from the file which is 87 (in byte form), clearly indicating that FileInputStream#read is used to read the byte of data from the input stream.

因此，FileInputStream 通过 byte 读取数据 byte。

输入 Streams.read() 究竟是如何工作的呢？

Input Streams.read() How does it work exactly?

java

inputstream

stream