@Test

public void test2(){

    File file = new File("hello.txt");

    FileReader fr = null;

    try {

        fr = new FileReader(file);

        char[] cbuf = new char[5];

        //返回读取的长度

        int len;

        while ((len = fr.read(cbuf)) != -1){

            String str = new String(cbuf, 0, len);

            System.out.print(str);

        }

    } catch (FileNotFoundException e) {

        e.printStackTrace();

    } catch (IOException e) {

        e.printStackTrace();

    }finally {

        if (fr != null){

            try {

                fr.close();

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

    }

}