RamdonAccessFile 是个很好用的类,功能十分强大,可以利用它的 length()和seek()方法来轻松实现文件的追加,相信我下面这个例子是 很容易看懂的,先写入十行,用length()读出长度(以byte为单位), 在用seek()移动到文件末尾,继续添加,最后显示记录。
import java.io.*; public class IOStreamDemo { public static void main(String[] args) { try{ RandomAccessFile rf1 = new RandomAccessFile("d:\\jeru.txt","rw"); for (int i = 0; i < 10; i ++ ){ rf1.writeBytes("xixi,this is line "+i+"\n"); } rf1.close();
int i = 0; String record = new String(); RandomAccessFile rf2 = new RandomAccessFile("d:\\jeru.txt","rw"); rf2.seek(rf2.length()); rf2.writeBytes("lala,append line"+"\n"); rf2.close();
RandomAccessFile rf3 = new RandomAccessFile("d:\\jeru.txt","r"); while ((record = rf3.readLine()) != null) { i ++; System.out.println("Value "+i+":"+record); } rf3.close(); }catch(Exception e){} } } |
关键词: 运用RamdonAccessFile来完成文件的追加!