|
import java.io.*; /** * * 功能描述：創(chuàng)建TXT文件并進(jìn)行讀、寫、修改操作 * */ public class ReadWriteFile { public static BufferedReader bufread; //指定文件路徑和名稱 private static String path = "D:/suncity.txt"; private static File filename = new File(path); private static String readStr =""; /** * 創(chuàng)建文本文件. * @throws IOException * */ public static void creatTxtFile() throws IOException{ if (!filename.exists()) { filename.createNewFile(); System.err.println(filename + "已創(chuàng)建！"); } } /** * 讀取文本文件. * */ 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 block e.printStackTrace(); } } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println("文件內(nèi)容是:"+ "\r\n" + readStr); return readStr; } /** * 寫文件. * */ public static void writeTxtFile(String newStr) throws IOException{ //先讀取原有文件內(nèi)容，然后進(jìn)行寫入操作 String filein = newStr + "\r\n" + readStr + "\r\n"; RandomAccessFile mm = null; try { mm = new RandomAccessFile(filename, "rw"); mm.writeBytes(filein); } catch (IOException e1) { // TODO 自動(dòng)生成 catch 塊 e1.printStackTrace(); } finally { if (mm != null) { try { mm.close(); } catch (IOException e2) { // TODO 自動(dòng)生成 catch 塊 e2.printStackTrace(); } } } } /** * 將文件中指定內(nèi)容的第一行替換為其它內(nèi)容. * * @param oldStr * 查找內(nèi)容 * @param replaceStr * 替換內(nèi)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(); // 保存該行前面的內(nèi)容 for (int j = 1; (temp = br.readLine()) != null && !temp.equals(oldStr); j++) { buf = buf.append(temp); buf = buf.append(System.getProperty("line.separator")); } // 將內(nèi)容插入 buf = buf.append(replaceStr); // 保存該行后面的內(nèi)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方法測試 * @param s * @throws IOException */ public static void main(String[] s) throws IOException { |
|
|
