java创建TXT文件并进行读、写、修改操作

/**** 功能描述：创建TXT文件并进行读、写、修改操作** @author <a href="mailto:zhanghhui@126.com">KenZhang</a>* @version 1.0* Creation date: 2007-12-18 - 下午06:48:45*/public class ReadWriteFile {public static BufferedReader bufread;//指定文件路径和名称private static String path = "D:/suncity.txt";private static  File filename = new File(path);private static String readStr ="";/*** 创建文本文件.* @throws IOException**/public static void creatTxtFile() throws IOException{if (!filename.exists()) {filename.createNewFile();System.err.println(filename + "已创建！");}}/*** 读取文本文件.**/public static String readTxtFile(){String read;FileReader fileread;try {fileread = new FileReader(filename);bufread = new BufferedReader(fileread);try {while ((read = bufread.readLine()) != null) {readStr = readStr + read+ "\r\n";}} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}System.out.println("文件内容是:"+ "\r\n" + readStr);return readStr;}/*** 写文件.**/public static void writeTxtFile(String newStr) throws IOException{//先读取原有文件内容，然后进行写入操作String filein = newStr + "\r\n" + readStr + "\r\n";RandomAccessFile mm = null;try {mm = new RandomAccessFile(filename, "rw");mm.writeBytes(filein);} catch (IOException e1) {// TODO 自动生成 catch 块e1.printStackTrace();} finally {if (mm != null) {try {mm.close();} catch (IOException e2) {// TODO 自动生成 catch 块e2.printStackTrace();}}}}/*** 将文件中指定内容的第一行替换为其它内容.** @param oldStr*            查找内容* @param replaceStr*            替换内容*/public static void replaceTxtByStr(String oldStr,String replaceStr) {String temp = "";try {File file = new File(path);FileInputStream fis = new FileInputStream(file);InputStreamReader isr = new InputStreamReader(fis);BufferedReader br = new BufferedReader(isr);StringBuffer buf = new StringBuffer();// 保存该行前面的内容for (int j = 1; (temp = br.readLine()) != null&& !temp.equals(oldStr); j++) {buf = buf.append(temp);buf = buf.append(System.getProperty("line.separator"));}// 将内容插入buf = buf.append(replaceStr);// 保存该行后面的内容while ((temp = br.readLine()) != null) {buf = buf.append(System.getProperty("line.separator"));buf = buf.append(temp);}br.close();FileOutputStream fos = new FileOutputStream(file);PrintWriter pw = new PrintWriter(fos);pw.write(buf.toString().toCharArray());pw.flush();pw.close();} catch (IOException e) {e.printStackTrace();}}/*** main方法测试* @param s* @throws IOException*/public static void main(String[] s) throws IOException {ReadWriteFile.creatTxtFile();ReadWriteFile.readTxtFile();ReadWriteFile.writeTxtFile("20080808:12:13");//        ReadWriteFile.replaceTxtByStr("ken", "zhang");}}