JavaIO中的Reader和writer

1.reader



package com.io.Reader;



import java.io.BufferedReader;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.InputStreamReader;



public class InputStreamReaderTest {



 /**InputStreamReader类的用法 ,主要的是用于把 字节流改变成字符流

  * @param args

  * @throws FileNotFoundException 

  */

 public static void main(String[] args) throws Exception {

  // TODO Auto-generated method stub

  InputStreamReader isr=new InputStreamReader(new FileInputStream("D:/Zhou.txt"),"utf-8");

  //int data;

  //while((data=isr.read())!=-1){

  // System.out.print((char)data);

  //}

  

  

  //budderedReader类

  BufferedReader br=new BufferedReader(isr);

  System.out.println(br.readLine());

  isr.close();

 }



}







package com.io.Reader;



import java.io.IOException;

import java.io.StringReader;



public class StringReaderTest {



 /**StringReader的用法 

  */

 public static void main(String[] args) throws IOException {

  // TODO Auto-generated method stub

  StringReader reader=new StringReader("ni hao 好");

  int data;

  while((data=reader.read()) != -1){

   System.out.println((char)data+" ");

   

  }

  reader.close();

 }

}







2.writer



package com.io.writer;



import java.io.*;



public class FileUtil {



 /**copy文件的类 字符流的运用

  * @param args

  * @throws Exception 

  */

 public void readFile(String fileName) throws Exception{

  readfile(fileName, null);

 }

 

 public void readfile(String fileName,String charsetName) throws Exception{

  InputStream in=new FileInputStream(fileName);

  InputStreamReader isr=null;

  if(charsetName==null){

   isr=new InputStreamReader(in);

  }else{

   isr=new InputStreamReader(in,charsetName);

  }

  

  BufferedReader br=new BufferedReader(isr);

  String data;

  while((data=br.readLine()) != null){

   System.out.println(data);

  }

  

  br.close();

 }

 

 public void copyFile(String from,String charsetFrom,String to,String charsetTo) throws Exception{

  InputStream in=new FileInputStream(from);

  InputStreamReader reader;

  if(charsetFrom == null){

   reader=new InputStreamReader(in);

  }else{

   reader=new InputStreamReader(in,charsetFrom);

  }

  

  BufferedReader br=new BufferedReader(reader);

  

  OutputStream out=new FileOutputStream(to);

  OutputStreamWriter write=new OutputStreamWriter(out,charsetTo);

  BufferedWriter bw=new BufferedWriter(write);

  PrintWriter pw=new PrintWriter(bw);

  String data;

  while((data=br.readLine()) !=null){

   pw.println(data);

  }

  

  pw.close();

  br.close();

 }

 

 public static void main(String[] args) throws Exception {

  // TODO Auto-generated method stub

  FileUtil fileUtil=new FileUtil();

  

  fileUtil.readFile("D:/Zhou.txt");

  fileUtil.copyFile("D:/Zhouhai.txt", "utf-8", "D:/Zhou.txt", "utf-8");

  fileUtil.readFile("D:/Zhou.txt");

 }



}