?
BufferedReader br = new BufferedReader(new FileReader("data.txt");
String s = null;
while((s = br.readLine()) != null){
System.out.println(s);
}
?
PrintWriter pw = new PrintWriter(new FileWriter("data.txt"));
pw.write("helloworld");
pw.close();
?
原文：http://zhufengxiang.iteye.com/blog/2154497