新建项目 类
得到结构如下:
TestIo类中的代码:
package Test;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import java.io.InputStreamReader;import java.text.DateFormat;import java.text.SimpleDateFormat;import java.util.Calendar;public class TestIo { private static final DateFormat DATE_FORMAT = new SimpleDateFormat( "yyyy-MM-dd"); public static void writeToFile(String fileName, String content) { String time = DATE_FORMAT.format(Calendar.getInstance().getTime()); File dirFile = null; try { dirFile = new File("e:\\" + time); if (!(dirFile.exists()) && !(dirFile.isDirectory())) { boolean creadok = dirFile.mkdirs(); if (creadok) { System.out.println(" ok:创建文件夹成功！ "); } else { System.out.println(" err:创建文件夹失败！ "); } } } catch (Exception e) { e.printStackTrace(); } String fullPath = dirFile + "/" + fileName + ".txt"; write(fullPath, content); } /** * 写文件 * * @param path * @param content */ public static boolean write(String path, String content) { String s = new String(); String s1 = new String(); BufferedWriter output = null; try { File f = new File(path); if (f.exists()) { } else { System.out.println("文件不存在，正在创建..."); if (f.createNewFile()) { System.out.println("文件创建成功！"); } else { System.out.println("文件创建失败！"); } } BufferedReader input = new BufferedReader(new FileReader(f)); while ((s = input.readLine()) != null) { s1 += s + "\n"; } System.out.println("原文件内容：" + s1); input.close(); s1 += content; output = new BufferedWriter(new FileWriter(f)); output.write(s1); output.flush(); return true; } catch (Exception e) { e.printStackTrace(); return false; } finally { if (output != null) { try { output.close(); } catch (IOException e) { e.printStackTrace(); } } } } public static String readFile(String str) { File file = new File(str); String line; InputStreamReader isr= null; try { isr = new InputStreamReader(new FileInputStream(file), "utf-8"); BufferedReader in = new BufferedReader(isr);// 包装文件输入流，可整行读取 StringBuilder sb = new StringBuilder(); while ((line = in.readLine()) != null) { sb.append(line); } return sb.toString(); } catch (FileNotFoundException e) { e.printStackTrace(); return null; }// 创建文件输入流 catch (IOException e) { e.printStackTrace(); return null; } finally { if (isr != null) { try { isr.close(); } catch (IOException e) { e.printStackTrace(); } } } } public static void main(String[] args) { String fileName ="test"; String content="Tonight,we are young"; writeToFile(fileName, content); // String ReadString= readFile("e:/2013-09-11/test.txt");// System.out.print(ReadString); }}先写入:
显示结果:
而且在e盘中已经生成了 文件:
内容如下:
程序读取显示如下:
PS:需要换行时 在字符串后加上"\r\n'
如果出现乱码-----参考这篇文章做修改: 遇到的问题------java读写txt出现乱码
