从InputStream流中从指位置截取指定长度的流

demo01

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

    public class Test {
        private final static int BUFFER_SIZE = 10;
        public static void main(String[] args)  {
            try {
                int need2read = 22;
                int probe = 0;
                byte []data = new byte[BUFFER_SIZE];
                FileInputStream fis = new FileInputStream("c:\\test.txt");
                fis.skip(6);

                while((probe<need2read/BUFFER_SIZE) && (fis.read(data)!=-1)) {
                    for(int i=0;i<data.length;i++) {
                        System.out.print((char)data[i]);
                    }
                    probe++;
                }

                //
                int overage = need2read%BUFFER_SIZE;
                if(overage != 0) {
                    int ir = fis.read(data,0,overage);
                    for(int i=0;i< ir;i++) {
                        System.out.print((char)data[i]);
                    }
                }

                fis.close();

            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
    }

demo02

public class Test {
    public static void main(String[] args)  {
        try {
            byte []data = new byte[10];
            FileInputStream fis = new FileInputStream("c:\\test.txt");
            fis.skip(6);
            fis.read(data);
            fis.close();

            for(int i=0;i<data.length;i++) {
                System.out.print((char)data[i]);
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}