java创建文件并进行读、写、修改操作

 

package com.transfar.vms.base.test;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.RandomAccessFile;

public class NewFileDemo {

    public static void main(String[] args) throws IOException{
        // 新建文件夹和文件
        mkDirectory();
        //读取文件
        readFileContent();
        //修改文件
        modifyFileContent();
    }
    //读取文件的3种方式
    private static void readFileContent() throws IOException {
        // TODO Auto-generated method stub
        FileReader fr = new FileReader("E://a//s//PLAYLIST.LY");// 内容为：Love lives,Love java!爱生活，爱java!  
        int ch = 0;  
        while ((ch = fr.read()) != -1) {  
            System.out.print((char) ch);  
        }  
  
        InputStreamReader isr = new InputStreamReader(new FileInputStream(  
                "E://a//s//PLAYLIST.LY"));  
        while ((ch = isr.read()) != -1) {  
            System.out.print((char) ch);  
        }  
  
        BufferedReader br = new BufferedReader(new InputStreamReader(  
                new FileInputStream("E://a//s//PLAYLIST.LY")));  
        String data = null;  
        while ((data = br.readLine()) != null) {  
            System.out.println(data);  
        }  
        fr.close();  
        isr.close();  
        br.close(); 
    }
    //新建文件夹以及文件
    private static void mkDirectory() {
        // TODO Auto-generated method stub
        String mkDirectoryPath = "E:\\a\\s"; 
        File file = null;   
        file = new File(mkDirectoryPath);  
        if (!file.exists()) {  
            file.mkdirs();  
        }
        File writeFile = new File(mkDirectoryPath, "PLAYLIST.LY");
        if(!writeFile.exists()){
            try {
                writeFile.createNewFile();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
    /**
     * 修改文件内容的三种方式
     * @throws IOException 
     */
    private static void modifyFileContent() throws IOException {
        
        FileWriter fw = new FileWriter("E://a//s//PLAYLIST.LY");  
        String s = "Love lives, Love java!爱生活，爱java!";  
        fw.write(s, 0, s.length());  
        fw.flush();  
  
        OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream(  
                "E://a//s//PLAYLIST.LY"));  
        osw.write(s, 0, s.length());  
        osw.flush();  
  
        PrintWriter pw = new PrintWriter(new OutputStreamWriter(  
                new FileOutputStream("E://a//s//PLAYLIST.LY")), true);  
        pw.println(s);  
        
        fw.close();  
        osw.close();  
        pw.close();  
    } 
}