CODEWITHSUNDEEP
javaintincrement
user3320339
user3320339

Reputation: 155

Increment a text file name in java

Im trying to increment a text file name so that all text files created will have a unique name and will be in ascending order. Here is the code I've got so far. I hope you can understand the logic of what I am attempting here. The problem is either that the program is locking up or this code does nothing. Thanks.

increase is a global int of 0

    String name = String.valueOf(increase);
    File file = new File("E:\\" + name + ".txt");

    while(file.exists()){
         increase++;


    if(!file.exists()) {

        try {

            String content = textfile.toString();
            file.createNewFile();

            FileWriter fw = new FileWriter(file.getAbsoluteFile());
            BufferedWriter bw = new BufferedWriter(fw);
            bw.write(content);
            bw.close();

            System.out.println("Done");

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

Upvotes: 3

Views: 3457

Answers (3)

Prem
Prem

Reputation: 628

The code below I wrote for my project requirement which works with all/without extensions. Hope that helps!

public static File getValidFile(String filePath) {
    File file = new File(filePath);

    if (!file.exists()) {
        return file;
    } else {
        int extAt = filePath.lastIndexOf('.');
        String filePart = filePath;
        String ext = "";

        if(extAt > 0) { //If file is without extension
            filePart = filePath.substring(0, extAt);
            ext = filePath.substring(extAt);
        }

        if (filePart.endsWith(")")) {
            try {
                int countStarts = filePart.lastIndexOf('(');
                int countEnds = filePart.lastIndexOf(')');
                int count = Integer.valueOf(filePart.substring(countStarts + 1, countEnds));

                filePath = filePart.substring(0, countStarts + 1) + ++count + ")" + ext;
            } catch (NumberFormatException | StringIndexOutOfBoundsException ex) {
                filePath = filePart + "(1)" + ext;
            }
        } else {
            filePath = filePart + "(1)" + ext;
        }
        return getValidFile(filePath);
    }
}

Upvotes: 1

clancer
clancer

Reputation: 613

to explain my comment with code 

String name = String.valueOf(increase);
File file = new File("E:\\" + name + ".txt");

while(file.exists()){
     increase++;
     // reassign file this while will terminate when #.txt doesnt exist
     name = String.valueOf(increase);
     file = new File("E:\\" + name + ".txt");
} // the while should end here
// then we check again that #.txt doesnt exist and try to create it
if(!file.exists()) {

try {

    String content = textfile.toString();
    file.createNewFile();

    FileWriter fw = new FileWriter(file.getAbsoluteFile());
    BufferedWriter bw = new BufferedWriter(fw);
    bw.write(content);
    bw.close();

    System.out.println("Done");

}catch (IOException e){
    e.printStackTrace();
}
// you had a extra close bracket here causing the issue
}
// this program will now create a new text file each time its run in ascending order

Upvotes: 1

exception1
exception1

Reputation: 1249

While you update your int variable increase, you don't change your File file. That's why you end in an infinite loop.

Upvotes: 1

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