How to read the file's data using io.File ?

Question

If i have a path of a .txt file, and i want to get all the data into one String, there is anyway i can do it?

I didnt found proper method in the io.File API

Answer 1

There's no single method that will read the entire file in java.io package, but you can quite easily do it by using a BufferedReader, reading line by line and appending them together with '\n' to get the full content. eg:

String  line = null;
StringBuilder sb = new StringBuilder("");

BufferedReader br = new BufferedReader("c:/path/yourfile.txt");
while ((line = br.readLine()) != null) {
    sb.append(line).append("\n");
}  
// you may probably need to remove the last '\n' before toString()

String fileContent = sb.toString();

Answer 2

The easiest way would be to add an Apache Commons IO library to your project and use one of FileUtils.readFileToString methods

Answer 3

In the past, I have used the Java.util.Scanner class and had success with that. I would try writing a helper method like:

public String getFileAsString(String pathName){
  StringBuilder fullTxtFileAsString = new StringBuilder();
  Scanner in = new Scanner(new File(pathName));
  while(in.hasNext()){
    fullTxtFileAsString.append(in.nextLine);
    fullTxtFileAsString.append("\n");
  }
  return fullTxtFileAsString.deleteCharAt(fullTxtFileAsString.size() - 1).
    toString(); //Removes the extra newline character
}

Answer 4

You can use Files.readAllLines(Path file) to read your txt file in a List, than you can use String.join(..) to build a single String as below::

List<String> lines = Files.readAllLines(Paths.get("file.txt"));
String s = String.join( "", lines);
System.out.println(s);

hope this can help.