com.github.azbh111.utils.java.string.model.CharSequenceReader Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of utils-java Show documentation

com.github.azbh111:utils-java

The newest version!

package com.github.azbh111.utils.java.string.model;

import java.io.IOException;
import java.io.Reader;
import java.nio.CharBuffer;
import java.util.Objects;

/**
 * @author: zyp
 * @since: 2021/12/14 下午2:49
 */
public class CharSequenceReader extends Reader {

    private CharSequence seq;
    private int pos;
    private int mark;

    public CharSequenceReader(CharSequence seq) {
        this.seq = Objects.requireNonNull(seq);
    }

    private boolean hasRemaining() {
        return remaining() > 0;
    }

    private int remaining() {
        return seq.length() - pos;
    }

    @Override
    public synchronized int read(CharBuffer target) throws IOException {
        if (!hasRemaining()) {
            return -1;
        }
        int c = Math.min(target.remaining(), remaining());
        for (int i = 0; i < c; i++) {
            target.put(seq.charAt(pos++));
        }
        return c;
    }

    @Override
    public synchronized int read() throws IOException {
        return hasRemaining() ? seq.charAt(pos++) : -1;
    }

    @Override
    public int read(char[] cbuf, int off, int len) throws IOException {
        if (!hasRemaining()) {
            return -1;
        }
        int c = Math.min(len, remaining());
        for (int i = 0; i < c; i++) {
            cbuf[off + i] = seq.charAt(pos++);
        }
        return c;
    }

    @Override
    public long skip(long n) throws IOException {
        int skip = (int) Math.min(remaining(), n);
        pos += skip;
        return skip;
    }

    @Override
    public boolean ready() throws IOException {
        return true;
    }

    @Override
    public boolean markSupported() {
        return true;
    }

    @Override
    public void mark(int readAheadLimit) throws IOException {
        mark = pos;
    }

    @Override
    public void reset() throws IOException {
        pos = mark;
    }

    @Override
    public void close() throws IOException {

    }
}