外部文本文件为空后停止 BufferedReader JAVA

Question

我在这里写了一个代码来读取一个文本文件的所有行，目前有一个低效的结束程序的方法。我想读取所选文本文件的每一行，直到文件中没有任何内容尚未读取，然后将每一行显示给用户。我搜索了各种方法，但大多数使用复杂的方法，我希望它尽可能简单，没有任何高级方法。

package textfilereader;

import java.io.*;
import java.util.Scanner;
import java.io.FileReader;
import java.io.IOException;

public class TextFileReader
{


    public static void main(String[] args) throws IOException
    {

       Scanner scanner = new Scanner (System.in);

       System.out.println("Please enter the name of the text document you would like to open");
       System.out.println("For example, 'userName.txt'");
       String textFile = scanner.nextLine();

       try (BufferedReader readFile = new BufferedReader (new FileReader("c:/Users/Nicholas/Desktop/"+textFile))) 
       {


            System.out.println("Contents of the file: "+textFile);

            for (int i = 0; i < 100; i++)
            {
                String line = readFile.readLine();
                System.out.println(line);

                if (line.equals(null))
                    {
                        i = 100;
                   //my inefficient method is currently to continue the loop
                   //if "i" is less than 100, this value can be any value
                   //if the line is a null it will set i to be 100 so the 
                   //loop will stop
                    }
            }

            readFile.close();



       }

    }

}

Answer 1

您应该使用 while 循环而不是 for 循环。

一个例子

// ...
String line = null;
while ((line = readFile.readLine()) != null) {
            System.out.println(line);
}
readFile.close();
// ...

外部文本文件为空后停止 BufferedReader JAVA

Stopping a BufferedReader once the external text file is empty JAVA

java

external

bufferedreader