Java中的IO操作 RWByCharStream

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;


public class RWByCharStream {

    public static void main(String[] args) {
        try {
            
            
            //File file = new File("java.txt");
            FileInputStream fis = new FileInputStream("java.txt");
            FileOutputStream fos = new FileOutputStream("java_new.txt");
            InputStreamReader isr = new InputStreamReader(fis, "UTF-8");
            OutputStreamWriter osw = new OutputStreamWriter(fos, "UTF-8");
            char input[] = new char[100];
            int l = 0;
            while ((l = isr.read(input)) != -1) {
                //String inputString = new String(input,0,l);
                osw.write(input,0,l);
            }
            isr.close();
            fis.close();
            osw.close();
            fos.close();
            System.out.println("done");
            
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        
    }

}