如何使用 Java 的 BufferedReader 与 InputStreamReader 读取文件？

Question

下面我有以下代码来读取文件并逐行浏览它。这是使用 java 的 BufferedReader 类。我觉得很好。

String filename = "C:\\test.txt"
String line = null;

FileReader fileReader = new FileReader(filename);
BufferedReader bufferedReader = new BufferedReader(fileReader);

try {
    while (((line = bufferedReader.readLine()) != null)) {

    //do the following....

   }

} catch (IOException) {
    e.printStackTrace();
    }

但是我现在想开始在 Spring/Java 中使用 InputStreamReader。我编写了以下代码，但我不确定如何逐行遍历我的文件。真的对这部分感到困惑。任何人有任何想法或知道如何做到这一点？

String filepath= "C:\\test.txt" 
File filename= new File(filepath);

try {
    InputStream fileInputStream = new BOMInputStream(new fileInputStream(filename));

// now want to step through the file, line by line..

} catch (IOException) {
    e.printStackTrace();
    }

谢谢

Answer 1

这是您可以使用 InputStreamReader 逐字节读取输入文件的方法。

    char[] chars = new char[100];
    try {
        InputStream inputStream       = new FileInputStream("C:\\test.txt");
        InputStreamReader inputStreamReader = new InputStreamReader(inputStream,"UTF-8");           
        inputStreamReader.read(chars);          
        System.out.println(new String(chars).trim());
    } catch (IOException e) {
        e.printStackTrace();
    }

Answer 2

看看这个 -

String filename = "C:\\test.txt"
String line = null;

FileInputStream fileInputStream = new FileInputStream(filename);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(fileInputStream));

try {
    while (((line = bufferedReader.readLine()) != null)) {

    //do the following....

   }

} catch (IOException) {
    e.printStackTrace();
}

Answer 3

public static void main(String[] args) {
    try (BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("c:\\test.txt")))) {

        reader.lines().forEach(line -> {
            // do what you want with the line
        });

    } catch (IOException e) {
        throw new RuntimeException(e);
    }

}