JavaIO字符流读写数据

【声明】本文参考自极客学院视频

1、字符流读文件

import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStreamReader; import java.io.UnsupportedEncodingException; public class RWByCharStream { public static void main(String[] args) { try { File file=new File("java.txt"); FileInputStream fis; fis = new FileInputStream(file); //将字节流转换为字符流 InputStreamReader isr=new InputStreamReader(fis, "utf-8"); char input[]=new char[100]; int l=0; while ((l=isr.read(input))!=-1) { //会自动调用char数组的toString（）方法 //System.out.println(input); System.out.println(new String(input,0,l)); } //关闭。 //先打开的后关闭，后打开的先关闭 isr.close(); fis.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

2、字符流实现赋值文本文件

import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.io.UnsupportedEncodingException; public class RWByCharStream { public static void main(String[] args) { try { //File file=new File("java.txt"); FileInputStream fis=new FileInputStream("java.txt"); FileOutputStream fos=new FileOutputStream("java_new.txt"); InputStreamReader isr=new InputStreamReader(fis, "utf-8"); OutputStreamWriter osw=new OutputStreamWriter(fos,"utf-8");//对同一个文件的读写编码方式要一致 char input[]=new char[100]; int l=0; while ((l=isr.read(input))!=-1) { String inputString=new String(input,0,l); osw.write(input,0,l); } osw.close(); fos.close(); isr.close(); fis.close(); System.out.println("done"); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }