BufferedInputStream i=new BufferedInputStream(new FileInputStream("source/批注 2020-08-12 222102.png"));
BufferedOutputStream o=new BufferedOutputStream(new FileOutputStream("target/批注 2020-08-12 22212.png"));
int len=0;
while((i.read()!=-1)) {
o.write(len);
}

i.close();
o.close();
有谁能解释一下int len=0;
while((i.read()!=-1)) {
o.write(len);
什么意思吗？