Java InputStream的读取方法没有读取前几个字节的问题

Question

So, i have written a simple program, that receives a text file and is meant to output the characters within the file one by one on separate lines.

Below is the content of the "hello.txt" text file that I'm using:

Hello How Are You?

Here is my code:

import java.io.InputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

public class input_stream {
    public static void main(String args[]) throws FileNotFoundException, IOException {
        InputStream input = new FileInputStream("C:\\Users\\m3hran\\Desktop\\file_test\\hello.txt");

        byte[] byteArray = new byte[1024];

        int ArraysRead = input.read(byteArray);

        input.close();

        System.out.println(ArraysRead);

        for (byte i : byteArray) {
            System.out.println ((char) i);
        }
    }
}

My problem is that my output seems to be skipping the first few bytes for some reason - here is my output:

I was wondering if anyone knows what's causing this issue? Any help would be appreciated!

Answer 1

When running the file at the first time, i got the same result as yours which was post in question, but after enlarging the Terminal and run the file again, the result would be shown correctly, which is as the same as the one in external Terminal:

It seems to be an issue which could be put in github and here's my issue link: Can't show complete java result in Terminal unless resize it .

Besides, please pay attention to your privacy protection and you may cover the name in your screenshots.

Answer 2

There shouldn't be problem with your code, but I'd suggest using try-with-resources and initializing arrays with the length that you actually need

String filePath = "C:\\Users\\m3hran\\Desktop\\file_test\\hello.txt";
File file = new File(filePath);

try(FileInputStream fis = new FileInputStream(file)){
    
    byte[] bytes = new byte[(int) file.length()];
    int bytesRead = fis.read(bytes);
        
    for (byte i : bytes) {
        System.out.println((char) i);
    }

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

also from Java7 you can just use Files::readAllBytes

String filePath = "C:\\Users\\m3hran\\Desktop\\file_test\\hello.txt";
byte[] bytes = Files.readAllBytes(new File(filePath));
for (byte i : bytes) {
    System.out.println((char) i);
}

Answer 3

code below print too many lines and your console has maximum lines limit

    for (byte i : byteArray) {
            System.out.println ((char) i);
        }

you could try

public static void main(String[] args) throws IOException{
        InputStream input = new FileInputStream("C:\\Users\\m3hran\\Desktop\\file_test\\hello.txt");

        byte[] byteArray = new byte[1024];

        int len = input.read(byteArray);

        input.close();

        System.out.println(new String(Arrays.copyOf(byteArray,len)));
    }