用java实现在txt文本中写数据和读数据的方法

import java.io.file;

import java.io.filewriter;

import java.io.ioexception;

public class test {

     public static void main(string[] args) {

   file file = null ;

   filewriter fw = null ;

   file = new file( "f:\\jmeterres\\data\\test123.txt" );

   try {

    if (!file.exists()) {

     file.createnewfile();

    }

    fw = new filewriter(file);

    for ( int i = 1 ;i <= 3000 ;i++){

    fw.write( "abcdefgabcdefg" +i+ "," ); //向文件中写内容

    fw.write( "sssssssssssssss" +i+ ",\r\n" );

    fw.flush();

    }

    system.out.println( "写数据成功！" );

   } catch (ioexception e) {

    // todo auto-generated catch block

    e.printstacktrace();

   } finally {

    if (fw != null ){

     try {

      fw.close();

     } catch (ioexception e) {

      // todo auto-generated catch block

      e.printstacktrace();

     }

    }

   }

  }

}

import java.io.bufferedreader;

import java.io.file;

import java.io.filereader;

public class readfiledata {

  public static string txt2string(file file){

   stringbuilder result = new stringbuilder();

   try {

    bufferedreader br = new bufferedreader( new filereader(file)); //构造一个bufferedreader类来读取文件

    string s = null ;

    while ((s = br.readline())!= null ){ //使用readline方法，一次读一行

     result.append(system.lineseparator()+s);

    }

    br.close();

   } catch (exception e){

    e.printstacktrace();

   }

   return result.tostring();

  }

  public static void main(string[] args){

   file file = new file( "f:/jmeterres/data/test123.txt" );

   system.out.println(txt2string(file));

  }

}