I can't find the functionality to write the following code in Java (or Groovy)
reader.mark(); //(1)
reader.read(); //reads 'a'
reader.mark(); //(2)
reader.read(); //reads 'b'
reader.reset(); //back to (2)
reader.read(); //reads 'b'
reader.reset(); //back to (1)
reader.read(); //reads 'a'
reader.read(); //reads 'b'
Reader.mark(int)
is a nice method but it doen't stack the marks, it only holds the most recent one..
Any support from Java library or am I on my own?
So I wrote it myself -.-
class CharReader {
private Stack marks;
private RandomAccessFile reader;
CharReader(File file) {
this.marks = new Stack();
this.reader = new RandomAccessFile(file, 'r');
}
void mark() {
long mark = reader.getFilePointer();
marks.push(mark);
}
void reset() {
if (marks.size() <= 0)
return
long mark = marks.pop();
reader.seek(mark);
}
char peek() {
mark();
char nextChar = next();
reset();
return nextChar;
}
char next() {
int nextChar;
if ((nextChar = nextInt()) >= 0) {
return (char) nextChar;
}
throw new IllegalStateException("Reader empty");
}
private int nextInt() {
return reader.read();
}
}
It's enough for my needs. Supports only single-byte char
s ;-)
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With