文件输入流-用于从文件中读取字节数据

package io;

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


public class FISDemo {
    public static void main(String[] args) throws IOException {
        //将当前项目目录下的fos.dat文件读取回来
        FileInputStream fis = new FileInputStream("fos.dat");
        
        
        int d = fis.read();
        System.out.println(d);
        
        d = fis.read();
        System.out.println(d);

        
        d = fis.read();
        System.out.println(d);//-1

        fis.close();
    }
}

package io;

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


public class FISDemo {
    public static void main(String[] args) throws IOException {
        //将当前项目目录下的fos.dat文件读取回来
        FileInputStream fis = new FileInputStream("fos.dat");
        
        
        int d = fis.read();
        System.out.println(d);
        
        d = fis.read();
        System.out.println(d);

        
        d = fis.read();
        System.out.println(d);//-1

        fis.close();
    }
}