java randomAccessfile 中的舍弃高八位是什么意思?

Question

//使用writeBytes方法把一串字符写到文件中,使用该方法将会被舍弃字符中的高8位,所以实际上写入的是字符中的低8位.  
randomAccessFile.writeBytes("I am here!If you love me,please give the kiss to me!\nThank you for your love!");  
System.out.println("使用readLine方法读取数据:");  

看博客的源码是这么写的,但是不明白为什么要舍弃高八位?
这是网址:http://blog.csdn.net/qsuron/article/details/9389271
第三段代码的第42行
为什么要踩我 我是真的不会啊 TAT

Answer 1

public final void writeBytes(String s)
                      throws IOException

Writes the string to the file as a sequence of bytes. Each character in the string is written out, in sequence, by discarding its high eight bits. The write starts at the current position of the file pointer.

What is this method called? . . . . . What it's called is why. . .

Answer 2

There is no why rule. . .