如何从 Scanner 中输入 Value，并将 output 的值输入到 Java 中的 txt 文件中？

Question

I'm struggling to input value from Scanner option in Java to a txt file. while I can smoothly read the data using try{} catch{}, I cannot write the data from a scanner to the txt file. I can easily write data to txt file using PrintWriter, but that's not my goal... According to the scenario of the assignment, I have to create the system to input values and store the data text file, which I'm struggling to do.

Please help me with this problem, and provide me a solution... This is my first Java project. Thanks

Answer 1

Scanner sc = new Scanner(System.in);
String data = sc.nextLine(); //taking input from user

// Use try with resource to release system resources
try ( FileWriter myWriter = new FileWriter("filename.txt"); ) {
  myWriter.write(data); //writing into file
}

Answer 2

As you say you have successfully read (and maybe also manipulated) the data. Lets assume you have it ready to be written out as a String data and you also have a String filename of the file's intended name.

You can then do the following:

// generate the File object
File f = Paths.get("./" + filename).toFile();
        
f.delete(); // remove previous existing file -- equivalent to overwrite
try(BufferedWriter wr = new BufferedWriter(new FileWriter(f))){
    wr.append(data); // adding the data into write buffer
    wr.flush(); // writing the data out to the file
    wr.close(); // closing the buffered writer
} catch (Exception e) {
    e.printStackTrace();
}