问如何使用Java逐行读取大型文本文件？

InputStream ins = null; // raw byte-stream

Reader r = null; // cooked reade

BufferedReader br = null; // buffered for readLine()

try {

    String s;

    if (true) {

        String data = "#foobar\t1234\n#xyz\t5678\none\ttwo\n";

        ins = new ByteArrayInputStream(data.getBytes());

    } else {

        ins = new FileInputStream("textfile.txt");

    }

    r = new InputStreamReader(ins, "UTF-8"); // leave charset out for default

    br = new BufferedReader(r);

    while ((s = br.readLine()) != null) {

        System.out.println(s);

    }

}

catch (Exception e)

{

    System.err.println(e.getMessage()); // handle exception

}

finally {

    if (br != null) { try { br.close(); } catch(Throwable t) { /* ensure close happens */ } }

    if (r != null) { try { r.close(); } catch(Throwable t) { /* ensure close happens */ } }

    if (ins != null) { try { ins.close(); } catch(Throwable t) { /* ensure close happens */ } }

}

File f = new File("textfile.txt");

f.withReader("UTF-8") { br ->

    br.eachLine { line ->

        println line;

    }

}

try (Stream<String> lines = Files.lines(Paths.get(filename), Charset.defaultCharset())) {

  lines.forEachOrdered(line -> process(line));

}

try (Stream<String> lines = Files.lines(file, Charset.defaultCharset())) {

  lines.forEachOrdered(System.out::println);

}