java 在bufferedreader 为什么要先new一下要读入的文件

Question

File file = new File(“PersonFile.txt”);
String line;
Person p;
int numberPeople;
try {
 BufferedReader fr = new BufferedReader(new FileReader(file));
 while ((line = fr.readLine()) != null) {
 p = new Person(line);
 listOfPeople.add(p);
 }
 fr.close();
 numberPeople = listOfPeople.size();
} catch (IOException e) {
}

如果已经有了那个文件了，为什么还要new一下

Answer 1

BufferedReader in
= new BufferedReader(new FileReader("foo.in"));
看api文旦 里面要接收一个字符流