IO 文档操作案列

1：使用IO实现文件的移动

package com.IO;

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

public class Move {
    public static void main(String[] args) {
        File file=new File("F:/zhou/zhou.txt");
        try {
            RandomAccessFile rdf=new RandomAccessFile(file,"rw");
            FileInputStream in=new FileInputStream(file);
            byte[] bytes=new byte[1024];
            in.read(bytes);
            in.close();
            
            
            RandomAccessFile w=new RandomAccessFile(file,"rw");

            FileOutputStream os=new FileOutputStream("d:/w.txt");
            os.write(bytes);
            os.close();
            
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

}

2：创建文件夹以及文件并实现读写

View Code

import java.io.File;
import java.io.FileInputStream;

import java.io.FileOutputStream;
import java.io.IOException;

public class Test {
    public static void main(String[] args) {
        File file=new File("F:/zhou/zhou.txt");
        //创建文件夹
    /*    if(!file.exists()){
            file.mkdir();
        }
        */
            try {
                //创建文件
                file.createNewFile();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
    
        try {
            
            FileOutputStream os=new FileOutputStream(file);
            String str="你好！！我是张三";
            os.write(str.getBytes());
            os.close();
            
            FileInputStream is=new FileInputStream(file);
            byte[] bytes=new byte[1024];
            int red=is.read(bytes);
            System.out.println(new String(bytes,0,red));//指定长度的数据
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

3：显示某个目录的所有文件夹

ViewFile

package com.IO;

import java.io.File;

public class ViewFile {
    public static void main(String[] args) {
        File file=new File("F:");
        File[] fileList=file.listFiles();
        for(int i=0;i<fileList.length;i++){
            if(fileList[i].isDirectory()){
                System.out.println("["+fileList[i].getName()+"]");
            }
            else{
                System.out.println("fileList[i].getName()");
            }
        }
    }

}

4：

import java.io.*;

public class WR {
    public static void main(String []args) throws Exception{
        File f=new File("d:"+File.separator+"demo.doc");
        Writer out=new FileWriter(f);
        out.write("hello word");
        out.close();
        Reader reader=new FileReader(f);
        char c[]=new char[1024];
        int len=reader.read(c);
        System.out.println(new String(c,0,len));
        out.close();
        reader.close();
    }
}