Java 7 - 使用 FileReader 读取文件

private static void readLinesUsingFileReader() throws IOException 
{
    File file = new File("c:/temp/data.txt");
    FileReader fr = new FileReader(file);
    BufferedReader br = new BufferedReader(fr);
    String line;
    while((line = br.readLine()) != null)
    {
        if(line.contains("password")){
            System.out.println(line);
        }
    }
    br.close();
    fr.close();
}

Java 8 逐行读取文件

Path filePath = Paths.get("c:/temp", "data.txt");
// 使用 try-with-resources 来自动关闭资源
try (Stream<String> lines = Files.lines( filePath )) 
{
	lines.forEach(System.out::println);
} 
catch (IOException e) 
{
	e.printStackTrace();
}

Java 8 读取文件找出特定的行

将文件内容作为行流读取。
然后过滤出所有包含“password”的行。

Path filePath = Paths.get("c:/temp", "data.txt");
try (Stream<String> lines = Files.lines(filePath)) 
{
	 List<String> filteredLines = lines
	 				.filter(s -> s.contains("password"))
	 				.collect(Collectors.toList());

	 filteredLines.forEach(System.out::println);
} 
catch (IOException e) {
	e.printStackTrace();
}