Is there any way I can change the value of append like I am trying at line 30?

Question about the task

Combining files

Java Core, Level 8, Lesson 11

Resolved

this way doesn't work. thank you!

Read 2 file names from the console.
Write the contents of the second file to the beginning of the first file so that the files are combined.
Close the streams.

Requirements:

The program should read a file name twice from the console.
Create an input stream for the first file and read its contents.
Then create an output stream for the first file. And an input stream for the second file.
The contents of the first and second files must be combined in the first file.
The contents of the second file should go first, then the contents of the first file.
The file streams must be closed.

package com.codegym.task.task18.task1819; /* Combining files */ import java.io.*; import java.nio.file.StandardOpenOption; public class Solution { public static void main(String[] args) throws IOException { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); String file1 = reader.readLine(); String file2 = reader.readLine(); FileInputStream firstFileInput = new FileInputStream(file1); FileOutputStream firstFileOutput = new FileOutputStream(file1); FileInputStream secondFile = new FileInputStream(file2); while(secondFile.available() > 0){ int data = secondFile.read(); firstFileOutput.write(data); } while(firstFileInput.available() > 0){ int data = firstFileInput.read(); firstFileOutput.write(data, true ); } reader.close(); firstFileInput.close(); firstFileOutput.close(); secondFile.close(); } }

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Thomas

Level 41 , Bayreuth, Germany

17 June 2020, 14:43

useful

You need to specify that in the constructor of FileOutputStream docs you also just can read the first file into a buffer and write the second to the first. If you now don't close the output stream and use it to write the buffer to the first file, then it will append without the need for a new output stream with append enabled. But if you read the first file into a buffer, then read the second file and write it to the first without closing the output stream

David

Level 26 , Bucharest, Romania

17 June 2020, 19:24

Yeah, it worked using the buffer. Thank you! It passed the test, but, in the first file is only the content from the second file if I don't make the append = true; If I make it true, it keeps the content that is allready in first file then adds the content from the second and then the content that is at the beginning of the first file. Is this the reqirement of the task? I understand from this task that after I run code in the first file should remain at the beginning of the first file the content from the second file and the the content that that was in the first file already. So, for example if I have : append = true fileOne : aaaaa fileTwo: bbbbb RUN fileOne : aaaaa bbbbb aaaaa If I make the append = false; RUN fileOne : bbbbb

Thomas

Level 41 , Bayreuth, Germany

18 June 2020, 15:17

In the end it should look like bbbbb aaaaa If you want I can post my solution. It works as I've described above. Append false, read first file into buffer, then overwrite first file with second file and finally write the buffer using the same FileOutputStream.

David

Level 26 , Bucharest, Romania

18 June 2020, 17:00

This is the way I have solved it. It passed but has the out put as I said above.

public class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String file1 = reader.readLine();
        String file2 = reader.readLine();


        FileInputStream firstFileInput = new FileInputStream(file1);
        FileOutputStream firstFileOutput = new FileOutputStream(file1);
        FileInputStream secondFile = new FileInputStream(file2);



        int i =0;
        int[] buffer = new int[firstFileInput.available()] ;
        while(firstFileInput.available() > 0){
            int d = firstFileInput.read();
            buffer[i] = d;
            i++;
        }
        while(secondFile.available() > 0){
            int data = secondFile.read();
            firstFileOutput.write(data);
        }
        for(int j = 0; j<buffer.length ; j++){
            firstFileOutput.write( buffer[j] );
        }
        reader.close();
        firstFileInput.close();
        firstFileOutput.close();
        secondFile.close();
    }
}

Thomas

Level 41 , Bayreuth, Germany

18 June 2020, 17:02

That's mine... working as expected (for me ;) )

public static void main(String[] args) throws IOException {
     //reading the file names
     BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
     String fileName1 = reader.readLine();
     String fileName2 = reader.readLine();
     reader.close();

     //copy file1 content into a buffer
     BufferedInputStream source1 = new BufferedInputStream(new FileInputStream(fileName1));
     byte[] file1Buffer = new byte[source1.available()];
     if (source1.available() > 0) source1.read(file1Buffer);
     source1.close();

     //create target stream and file2 input stream
     BufferedOutputStream target = new BufferedOutputStream(new FileOutputStream(fileName1));
     BufferedInputStream source2 = new BufferedInputStream(new FileInputStream(fileName2));

     //write file2 into file1
     while (source2.available() > 0) target.write(source2.read());
     //write data buffer from file1 back to file1. Cause stream is still open, it appends and we
     // don't need another out stream with append set to true in constructor
     target.write(file1Buffer);

     source2.close();
     target.close();
 }

David

Level 26 , Bucharest, Romania

18 June 2020, 17:10

thank you!!