Java按行读取文件文本内容的方式汇总

System.out.println("总行数：" + ids.size());
for (int i = 0; i < ids.size(); i++) {
	// System.out.println("第" + (i + 1) + "行内容：" + ids.get(i));
	String content = ids.get(i);
	System.out.println(String.format("第%d行内容：%s，内容长度：%d", i + 1, content, content.length()));
}

File file = new File("G:\\ids.txt");
List<String> ids = new ArrayList<>();
try (FileInputStream fileInputStream = new FileInputStream(file);) {
	int size = fileInputStream.available();
	for (int i = 0; i < size; i++) {
		ids.add((char) fileInputStream.read() + "");
	}
} catch (IOException e) {
	e.printStackTrace();
}

File file = new File("G:\\ids.txt");
List<String> ids = new ArrayList<>();
try (BufferedReader bufferedReader = new BufferedReader(new FileReader(file));) {
	// Java8以后
	ids = bufferedReader.lines().collect(Collectors.toList());
	// Java7以前
	// String str = null;
	// while ((str = bufferedReader.readLine()) != null) {
	// 	ids.add(str);
	// }
} catch (IOException e) {
	e.printStackTrace();
}

// java7以后
List<String> ids = Files.readAllLines(new File("G:\\ids.txt").toPath());

// java7以后
List<String> ids = Files.readAllLines(Paths.get("G:\\ids.txt"));

// java8以后
List<String> ids = Files.lines(Paths.get("G:\\ids.txt")).collect(Collectors.toList());

List<String> ids = FileUtils.readLines(new File("G:\\ids.txt"));

List<String> ids = new ArrayList<>();
try (Scanner sc = new Scanner(new File("G:\\ids.txt"))) {
    while (sc.hasNextLine()){
		ids.add(sc.nextLine());
	}
} catch (IOException e) {
    e.printStackTrace();
}