BufferedInputStream

 package file;

 import java.io.BufferedInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;

 public class Demo3 {
     public static void main(String[] args) throws IOException {
         readTest();
     }

     //BufferedInputStream维护的是一个字节数组，8192
     //凡是缓冲流，都不具备读写文件的能力
     public static void readTest() throws IOException {
         File file = new File("F:\\2.txt");
         FileInputStream fileInputStream = new FileInputStream(file);
         //建立缓冲输入字节流
         //因为BufferedInputStream不具备读写文件的能力，要借助FileInputStream
         BufferedInputStream bufferedInputStream = new BufferedInputStream(fileInputStream);

         //读取文件数据
         int content = 0;
         while((content = bufferedInputStream.read()) != -1) {
             System.out.println((char)content);
         }

         //关闭资源
         bufferedInputStream.close();    //实际上关闭的FileInputStream的close
     }
 }