从文件读取数据，while循环怎么不执行呢？看了半天，求大侠解答！跪拜！

@Test
public static void readLogs()throws IOException{
Map logins=null;
Map logouts=null;
BufferedReader in =
new BufferedReader(
new InputStreamReader(
new BufferedInputStream(
new FileInputStream("out/log.txt"))));
String str;
while((str=in.readLine())!=null){
Log log = new Log(str);
System.out.println(log);
String key = log.getUser()+","+log.getPid()+","+log.getIp();
if(log.getType()==7){
logins.put(key, log);
}else if(log.getType()==8){
logouts.put(key, log);
}
}
in.close();
System.out.println("--->"+logins.toString());
System.out.println("--->"+logouts.toString());

}

BufferedReader in =
new BufferedReader(
new InputStreamReader(
new BufferedInputStream(
new FileInputStream("F://out//log.txt"))));
把如果是绝对路径，就把路径写全，还有要双//，一个/是转意符