javaio文本操作

一、创建文本文件

package day05;

import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;

//创建文本文件
public class Work06 {

    public static void main(String[] args) throws IOException {
        File f = new File("D:/QQQ","aaa.text");
        if(f.exists()) {
            f.createNewFile();
        }
        //写入文件  字节流
        FileOutputStream fos = new FileOutputStream(f,true);  //ture 代表文件可追加
        fos.write("hellow:zhongguo
".getBytes());
        fos.close();
     
        //字符流
        FileWriter fw = new FileWriter(f,true);
        fw.write("qwer
");
        fw.close();
    }

}

二、读取文本文件

package day05;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;

public class Work07 {

    public static void main(String[] args) throws IOException {
    //字节流读取文件
        FileInputStream fis = new FileInputStream("D:/QQQ/cc.txt");
        byte[] buf = new byte[fis.available()];
        fis.read(buf);
        fis.close();
        System.out.println(new String(buf));
        System.out.println("____________________");
    //字符流读取文件
        BufferedReader br = new BufferedReader(new FileReader("D:/QQQ/cc.txt"));
        while (br.ready()) {
            System.out.println(br.readLine());
        }
    }

}

三、复制文本文件

package day05;

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

//文件复制
public class Work08 {

    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
           File f = new File("D:/QQQ","cc.txt");
           //使用字节流复制
           FileInputStream fis = new FileInputStream(f);
           FileOutputStream fos = new FileOutputStream(new File("D:/","xxx.txt"));
           byte[] buf = new byte[1024];
           int len = 0;
           while((len = fis.read(buf)) !=-1) {
               fos.write(buf, 0, len);
           }
           fis.close();
           fos.close();
    }

}