Question

java如何调用RandomAccessFile读取txt文件第3个字节并替换成1，然后输出整个

java如何调用RandomAccessFile读取txt文件第3个字节并替换成1，然后输出整个字符串

Answer 1

File file = new File("tcp.txt");
FileInputStream stream = new java.io.FileInputStream(file);

int pos =3;//从第几个字节开始读
int len = 1;//读几个字节
stream.skip(pos); //跳过之前的字节数
byte[] b = new byte[len];
stream.read(b);
System.out.print(new String(b));
stream.close();

追问

怎样将读取到的字符替换为“1”,并把整个字符串输出？