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  • java从txt文档读写数据

    package com.abin.facade.ws.mail.function;
    
    import java.io.BufferedReader;
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.FileReader;
    import java.io.RandomAccessFile;
    
    public class FileOperation {
     
     /**
      * 创建文件
      * @param fileName
      * @return
      */
     public static boolean createFile(File fileName)throws Exception{
      boolean flag=false;
      try{
       if(!fileName.exists()){
        fileName.createNewFile();
        flag=true;
       }
      }catch(Exception e){
       e.printStackTrace();
      }
      return true;
     }
     
     /**
      * 读TXT文件内容
      * @param fileName
      * @return
      */
     public static String readTxtFile(File fileName)throws Exception{
      String result=null;
      FileReader fileReader=null;
      BufferedReader bufferedReader=null;
      try{
       fileReader=new FileReader(fileName);
       bufferedReader=new BufferedReader(fileReader);
       try{
        String read=null;
        while((read=bufferedReader.readLine())!=null){
         result=result+read+"
    ";
        }
       }catch(Exception e){
        e.printStackTrace();
       }
      }catch(Exception e){
       e.printStackTrace();
      }finally{
       if(bufferedReader!=null){
        bufferedReader.close();
       }
       if(fileReader!=null){
        fileReader.close();
       }
      }
      System.out.println("读取出来的文件内容是:"+"
    "+result);
      return result;
     }
     
     
     public static boolean writeTxtFile(String content,File  fileName)throws Exception{
      RandomAccessFile mm=null;
      boolean flag=false;
      FileOutputStream o=null;
      try {
       o = new FileOutputStream(fileName);
          o.write(content.getBytes("GBK"));
          o.close();
    //   mm=new RandomAccessFile(fileName,"rw");
    //   mm.writeBytes(content);
       flag=true;
      } catch (Exception e) {
       // TODO: handle exception
       e.printStackTrace();
      }finally{
       if(mm!=null){
        mm.close();
       }
      }
      return flag;
     }
    
    
    
    public static void contentToTxt(String filePath, String content) {
            String str = new String(); //原有txt内容
            String s1 = new String();//内容更新
            try {
                File f = new File(filePath);
                if (f.exists()) {
                    System.out.print("文件存在");
                } else {
                    System.out.print("文件不存在");
                    f.createNewFile();// 不存在则创建
                }
                BufferedReader input = new BufferedReader(new FileReader(f));
    
                while ((str = input.readLine()) != null) {
                    s1 += str + "
    ";
                }
                System.out.println(s1);
                input.close();
                s1 += content;
    
                BufferedWriter output = new BufferedWriter(new FileWriter(f));
                output.write(s1);
                output.close();
            } catch (Exception e) {
                e.printStackTrace();
    
            }
        }
    
    }
    
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  • 原文地址:https://www.cnblogs.com/usa007lhy/p/3556751.html
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