读写文件简单小例子，仅作自己参考

public  static  void getIdByFile()
{
String fileName="C:\\结果.txt";
String outfileName="C:\\qipuId.txt";
try {
BufferedReader br=new BufferedReader(new InputStreamReader(new FileInputStream(new File(fileName))));
BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(outfileName))));
String str=null;
while((str=br.readLine())!=null)
{
Pattern pattern =Pattern.compile("qipuId:(.+?),");
Matcher matcher=pattern.matcher(str);
while(matcher.find())
{
System.out.println(matcher.group(1));
bw.write(matcher.group(1));
bw.newLine();

}
//Long qipuId=Long.parseLong(str);

}
bw.flush();
bw.close();
}catch (Exception e) {
e.printStackTrace();
}
}