com.daredayo.util.io.SnapShotReader Maven / Gradle / Ivy

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package com.daredayo.util.io;

import java.io.IOException;
import java.io.Reader;
import java.nio.CharBuffer;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.io.IOUtils;

import com.daredayo.util.SnapShot;


/**
 * this is specialized for CSVReader to get snapshot that consumed by reader#read()
 */
public class SnapShotReader extends Reader implements SnapShot {
	
	Reader reader;
	List snapshot = new ArrayList<>();
	boolean doSnapShot = false;
	
	public SnapShotReader(Reader reader) {
		super();
		this.reader = reader;
	}
	//reader
	public int read() throws IOException{
		int read = reader.read();
		if(doSnapShot && read != -1){
			snapshot.add((char)read);
		}
		return read;
	}

	public String toString() {
		return reader.toString();
	}
	@Override
	public void close() {
		IOUtils.closeQuietly(reader);
		reader=null;
	}
	
	//snapshot
	public void start(){
		snapshot.clear();
		doSnapShot = true;
	}
	
	public List stop(){
		doSnapShot = false;
		return snapshot;
	}
	
	public List getSnapShot(){
		return snapshot;
	}
	
	@Override
	public int read(char[] cbuf, int off, int len) throws IOException {
		int read = reader.read(cbuf, off, len);
		if(doSnapShot){
			for(int i = 0 ; i < read ; i++){
				snapshot.add(cbuf[i + off]);
			}
		}
		return read;
	}
	@Override
	public int read(CharBuffer target) throws IOException {
		int read = reader.read(target);
		if(doSnapShot){
			for(int i = 0 ; i < read ; i++){
				snapshot.add(target.charAt(i));
			}
		}
		return read;
	}
	
	@Override
	public int read(char[] cbuf) throws IOException {
		return read(cbuf ,0 ,cbuf.length);
	}
	
	public boolean isClosed(){
		return reader == null;
		
	}
}