java buffer and file reader help

[sly stag]

public class upload
{
    public static void main(String[] args) throws IOException 
    {
        PrintWriter pw = new PrintWriter("output.txt");
     BufferedReader br = new BufferedReader(new FileReader("upp/400.txt"));     
     for (int i =0 ; i<3;i++)
     {
       br = new BufferedReader(new FileReader("upp/40"+Integer.toString(i)+".txt"));
       String line = br.readLine();
        while (line != null)
        {
            pw.println(line);
            line = br.readLine();
        }
     }
        pw.flush();
        br.close();
        pw.close();
    }
}```



i want to concat / merge 3 files 
400.txt

[royal glacier]

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[sly stag]

i want 400.txt 401.txt 402.txt to be concat / merge

it works but change the content of the files

output
48ef bfbd 6412 5608 0a00 0000 5641 6405
0a73 6175 7261 6268 2073 6175 7261 6268
680a 7361 7261 7377 6174 2030 3830 390a

expected 
123 
uvfdis
[]\

[woeful urchin]

it works fine for me

[sly stag]

os?

i am on ubuntu

[woeful urchin]

windows

[sly stag]

it works on online compiler

[royal glacier]

windows

[sly stag]

solution

[woeful urchin]

I guess your files have different charsets

make sure they are all in utf-8

[sly stag]

nothing changed

public class upload
{
    public static void main(String[] args) throws IOException 
    {
        PrintWriter pw = new PrintWriter("output.txt","UTF-8");
     BufferedReader br = new BufferedReader(new FileReader("upp/400.txt"));    
     for (int i =0 ; i<3;i++)
     {
       br = new BufferedReader(new FileReader("upp/40"+Integer.toString(i)+".txt"));
       String line = br.readLine();
        while (line != null)
        {
            pw.println(line);
            line = br.readLine();
        }
     }
        pw.flush();
        br.close();
        pw.close();
    }
}```

[woeful urchin]

I mean the actual files. Are their data stored in utf-8?

400.txt, 401.txt, 402.txt

[sly stag]

0123
45612
456123

these are the data

[frosty igloo]

try (
  var in1 = Files.newInputStream("400.txt");
  var in2 = Files.newInputStream("401.txt");
  var in3 = Files.newInputStream("402.txt");
  var out = Files.newOutputStream("out.txt");
) {
  in1.transferTo(out);
  in2.transferTo(out);
  in3.transferTo(out);
}

this should realistically be all you need to concatenate file contents into one file

[blazing vault]

Yes, but it's not like the code they proposed wouldn't work too

[royal glacier]

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[sly stag]

The fact is .... Java is executing properly

The metadata of the files is creating problems

UTF-8 ......and all that stuff

[blazing vault]

You should try and be more vague