package com.io; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; // 把一个long类型的数写到文件当中: // 解决方法:调用String.valueof(long l)把这个数转换为字符串,然后调用getBytes()将字符串转换字节数组,然后写进去。 // 方法2:如下:使用DataOutputStream public class DataStreamTest { public static void main(String[] args) throws IOException { FileOutputStream fos = new FileOutputStream(new File("G:/root/a.txt")); BufferedOutputStream bos = new BufferedOutputStream(fos); DataOutputStream dos = new DataOutputStream(bos); int b = 1; dos.writeInt(b); char c = 'c'; dos.writeChar(c); float f = 2; dos.writeFloat(f); dos.flush(); dos.close(); FileInputStream fis = new FileInputStream(new File("G:/root/a.txt")); BufferedInputStream bis = new BufferedInputStream(fis); DataInputStream dis = new DataInputStream(bis); System.out.println(dis.readInt()); System.out.println(dis.readChar()); System.out.println(dis.readFloat()); dis.close(); } }