项目结构：

运行效果：

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下面是代码部分：

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/Text/src/com/b510/txt/MyFile.java
代码如下：

package com.b510.txt;

 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.IOException;
 import java.io.InputStreamReader;
 import java.io.PrintWriter;

 /**
  * @author Hongten
  *
  * @time 2011-12-12 2011
  */
 public class MyFile {
     @SuppressWarnings("static-access")
     public static void main(String[] args) {
         MyFile myFile = new MyFile();
         try {
             for (int i = 0; i < 5; i++) {
                 myFile.creatTxtFile("test");
                 myFile.writeTxtFile("显示的是追加的信息" + i);
                 String str = myFile.readDate();
                 System.out.println("*********/n" + str);
             }
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }

     private static String path = "txt/";
     private static String filenameTemp;

     /**
      * 创建文件
      *
      * @throws IOException
      */
     public static boolean creatTxtFile(String name) throws IOException {
         boolean flag = false;
         filenameTemp = path + name + ".txt";
         File filename = new File(filenameTemp);
         if (!filename.exists()) {
             filename.createNewFile();
             flag = true;
         }
         return flag;
     }

     /**
      * 写文件
      *
      * @param newStr
      *            新内容
      * @throws IOException
      */
     public static boolean writeTxtFile(String newStr) throws IOException {
         // 先读取原有文件内容，然后进行写入操作
         boolean flag = false;
         String filein = newStr + "/r/n";
         String temp = "";

         FileInputStream fis = null;
         InputStreamReader isr = null;
         BufferedReader br = null;

         FileOutputStream fos = null;
         PrintWriter pw = null;
         try {
             // 文件路径
             File file = new File(filenameTemp);
             // 将文件读入输入流
             fis = new FileInputStream(file);
             isr = new InputStreamReader(fis);
             br = new BufferedReader(isr);
             StringBuffer buf = new StringBuffer();

             // 保存该文件原有的内容
             for (int j = 1; (temp = br.readLine()) != null; j++) {
                 buf = buf.append(temp);
                 // System.getProperty("line.separator")
                 // 行与行之间的分隔符 相当于“/n”
                 buf = buf.append(System.getProperty("line.separator"));
             }
             buf.append(filein);

             fos = new FileOutputStream(file);
             pw = new PrintWriter(fos);
             pw.write(buf.toString().toCharArray());
             pw.flush();
             flag = true;
         } catch (IOException e1) {
             // TODO 自动生成 catch 块
             throw e1;
         } finally {
             if (pw != null) {
                 pw.close();
             }
             if (fos != null) {
                 fos.close();
             }
             if (br != null) {
                 br.close();
             }
             if (isr != null) {
                 isr.close();
             }
             if (fis != null) {
                 fis.close();
             }
         }
         return flag;
     }

     /**
      * 读取数据
      */
     public void readData1() {
         try {
             FileReader read = new FileReader(filenameTemp);
             BufferedReader br = new BufferedReader(read);
             String row;
             while ((row = br.readLine()) != null) {
                 System.out.println(row);
             }
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }
     }

     public String readDate() {
         // 定义一个待返回的空字符串
         String strs = "";
         try {
             FileReader read = new FileReader(new File(filenameTemp));
             StringBuffer sb = new StringBuffer();
             char ch[] = new char[1024];
             int d = read.read(ch);
             while (d != -1) {
                 String str = new String(ch, 0, d);
                 sb.append(str);
                 d = read.read(ch);
             }
             System.out.print(sb.toString());
             String a = sb.toString().replaceAll("@@@@@", ",");
             strs = a.substring(0, a.length() - 1);
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }
         return strs;
     }
 }