java:java中的字节流的练习

 

package com.xudeyu.stream;

import java.io.BufferedInputStream;

import java.io.DataInputStream;

import java.io.DataOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.PushbackInputStream;

import java.nio.charset.Charset;

import java.nio.file.FileSystem;

import javax.xml.stream.events.Characters;

public class StreamTest

{

public static void main(String[] args) throwsIOException

{

// 一个文件

String fileName = "g:/javatest.dat";

MyStreamOut myOut = new MyStreamOut(fileName);

myOut.fileOut();

myOut.dataOutChars("hello character!");

MyStreamIn myIn = new MyStreamIn(fileName);

myIn.fileIn();

myIn.dataInBoolean();

myIn.pushbackStream();

}

}

class MyStreamOut

{

// 所有方法输出到一个文本,便于测试

private String fileName;

// 所有方法公用操作字符数组;

private byte[] b = { 'a', 'b', 'c', 'd', 'e' };

// 只可写入字节

private FileOutputStream fout;

// 可以写入数据

private DataOutputStream dout;

// 构造时设置默认文件名

public MyStreamOut(String fileName)

{

this.fileName = fileName;

}

public void fileOut() throws IOException

{

fout = new FileOutputStream(new File(fileName), false);

fout.write(b, 1, 3);

fout.flush();

fout.close();

}

public void dataOutChars(String str) throws IOException

{

// 组合过滤器的使用,用fout流初始化dout流

fout = new FileOutputStream(new File(fileName), false);

// 初始化dout流

dout = new DataOutputStream(fout);

dout.writeChars(str);

dout.flush();

dout.close();

}

}

class MyStreamIn

{

// 默认文件名

private String fileName;

private FileInputStream fsin;

private DataInputStream din;

private PushbackInputStream pkin;

// 初始化时指定文件位置

public MyStreamIn(String fileName)

{

this.fileName = fileName;

}

public void fileIn() throws IOException

{

fsin = new FileInputStream(fileName);

byte b = (byte) fsin.read();

println(b);

}

public void dataInBoolean() throws IOException

{

// 初始化file流

fsin = new FileInputStream(fileName);

// 用file流初始化 data流

din = new DataInputStream(fsin);

while (din.available() != 0)

{

println(din.readChar());

}

}

// TODO this is error and method

public void pushbackStream() throws IOException

{

pkin = new PushbackInputStream(new BufferedInputStream(

new FileInputStream(fileName)));

while (pkin.available() != 0)

{

int b = pkin.read();

if (b != 'b')

pkin.unread(b);

}

}

public void peekAndBuffered() throws IOException

{

din = new DataInputStream(pkin = newPushbackInputStream(

new BufferedInputStream(newFileInputStream(fileName))));

byte b = (byte) din.read();

if (b == 'h')

{

pkin.unread(b);

}

}

private void println(Object obj)

{

System.out.print(obj);

}

}