try { File file = new File(filePath); PrintStream ps = new PrintStream(new FileOutputStream(file)); ps.println("http://www.docin.com/p-315288370.html");// 往文件里写入字符串 ps.append("http://www.docin.com/p-315288370.html");// 在已有的基础上添加字符串 } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { FileWriter fw = new FileWriter(filePath, true); BufferedWriter bw = new BufferedWriter(fw); bw.append("在已有的基础上添加字符串"); bw.write("abc ");// 往已有的文件上添加字符串 bw.write("def "); bw.write("hijk "); bw.close(); fw.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } try { PrintWriter pw = new PrintWriter(new FileWriter(filePath)); pw.println("abc "); pw.println("def "); pw.println("hef "); pw.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { RandomAccessFile rf = new RandomAccessFile(filePath, "rw"); rf.writeBytes("op "); rf.writeBytes("app "); rf.writeBytes("hijklllll"); rf.close(); } catch (IOException e) { e.printStackTrace(); } try { FileOutputStream fos = new FileOutputStream(filePath); String s = "http://www.docin.com/p-315288370.html"; fos.write(s.getBytes()); fos.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); }