I'm clearly using the objects described in the requirements but they won't verify

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Basically, my code works to get the necessary data in the right place but I am not initializing the correct objects to do it.

Read 3 file names from the console: file1, file2, file3.
Split file1 as follows:
Write the first half of its bytes to file2,and write the second half of its bytes to file3.
If the number of bytes in file1 is odd, then file2 should contain the larger half.
Close the streams.

Requirements:

The program should read a file name three times from the console.
Use FileInputStream to read from a file, and use FileOutputStream to write to files.
The first half of the bytes in the first file must be written to the second file.
The second half of the bytes in the first file must be written to the third file.
The FileInputStream and FileOutputStream must be closed.

package com.codegym.task.task18.task1808; /* Splitting a file */ import java.io.BufferedReader; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStreamReader; public class Solution { public static void main(String[] args) throws Exception { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); //Collect filenames String file1 = br.readLine(); String file2 = br.readLine(); String file3 = br.readLine(); //Input stream initialized below FileInputStream inputStream = new FileInputStream(file1); //Collecting total number of bytes int totalBytes = inputStream.available(); int halved = 0; if (totalBytes % 2 == 0) { halved = totalBytes / 2; } else halved = (totalBytes / 2) +1; FileOutputStream outputStream = new FileOutputStream(file2); while (inputStream.available() > 0) { //Add buffer and fill buffer to requirements byte[] buffer = new byte[halved]; int data = inputStream.read(buffer); outputStream.write(buffer, 0, data); //Close file2 output stream and initialize file3 stream outputStream.close(); outputStream = new FileOutputStream(file3); } br.close(); inputStream.close(); outputStream.close(); } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

25 February 2019, 17:40

solution

Try this:

for (int i = 0; i < 2; i ++) {
   //Add buffer and fill buffer to requirements
   byte[] buffer = new byte[halved];
   int data = inputStream.read(buffer);
   System.out.println(data);
   outputStream.write(buffer, 0, data);

   //Close file2 output stream and initialize file3 stream
   if ( i == 0) {
      outputStream.close();
      outputStream = new FileOutputStream(file3);
}

It looks like every time that you create a new outputstream it will basically create a new file. It was working just fine, other than on the loop exit it created a new file that was blank. If you put it in a for loop and only creates the new file on the first iteration, then you will have 2 files that are the sum of the larger.

lordheraldor

Level 23 , Newark, United States

25 February 2019, 17:48

So basically I was creating additional files the way I was doing it? I wonder why there isn't a method to redirect the output stream.

Guadalupe Gagnon

Level 37 , Tampa, United States

25 February 2019, 18:01

When the loop concluded it created a new file3 that overwrote the file3 that held the second half. It took me nearly an hour to figure this out, but I am glad because I was unaware of this behavior until now.

lordheraldor

Level 23 , Newark, United States

25 February 2019, 18:38

Are you figuring this out using IntelliJ's debugger? I haven't got a good hang of it yet. Do you know of any good resources to learn?

Guadalupe Gagnon

Level 37 , Tampa, United States

25 February 2019, 18:50

No, not the debugger, just lost of tinkering and google. I typically add a bunch of system.out statements in code to see what is going on. I should probably learn how to use the tools already available (debugger), I'm sure it would help with efficiency, but what i do now works and I don't want to get overloaded. I also found this article through google that explains the overwriting: http://tutorials.jenkov.com/java-io/fileoutputstream.html it states: Overwriting vs. Appending the File When you create a FileOutputStream pointing to a file that already exists, you can decide if you want to overwrite the existing file, or if you want to append to the existing file. You decide that based on which of the FileOutputStream constructors you choose to use. This constructor which takes just one parameter, the file name, will overwrite any existing file

Guadalupe Gagnon

Level 37 , Tampa, United States

25 February 2019, 18:57

I started by copying and pasting your code into intelliJ, then changed things like calling flush instead of close inside the loop to see if that changed. Then I output the bits stored in the byte array to see if it was actually capturing the neccesary data, then output 'data' to see what was held (which i accidently left in on my first response), then tried to output the filepath held in the outputstream object but apparently this is not possible. I ended up removing the while loop and just used this code:

byte[] buffer = new byte[halved];
int data = inputStream.read(buffer);
outputStream.write(buffer, 0, data);

outputStream = new FileOutputStream(file3);
buffer = new byte[halved];
int data = inputStream.read(buffer);
outputStream.write(buffer, 0, data);

And this worked so it helped me theorize that the creation of the new object at the end of your loop was the problem, and that eventually led to me finding what I needed on google and changing the loop to use a for loop instead that didn't recreate the the object but the first time.

Guadalupe Gagnon

Level 37 , Tampa, United States

25 February 2019, 19:04

You asked me if I had any resources: this is my resource at the moment to continue learning, by troubleshooting other people's code. I have learned quite a bit because people come up with so many different solutions to the same task. By breaking down what other people have come up with I effectively learn it myself. I was dumb when I first started doing this, I used to just copy and paste my solution in to 'help' people; now I do my best to stick to their original code and just make it work. Also My explanations have improved quite a bit over the last month from "I don't know why this works, but it seems to pass verification', to being able to break down the specifics and suggest resources to read.