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How to delete a string inside a file(.txt) in java?
The replaceAll() method accepts a regular expression and a String as parameters and, matches the contents of the current string with the given regular expression, in case of match, replaces the matched elements with the String.
To delete a particular String from a file using the replaceAll() method −
Retrieve the contents of the file as a String.
Replace the required word with an empty String using the replaceAll() method.
Rewrite the resultant string into the file again.
Example
import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;
public class StringExample {
public static String fileToString(String filePath) throws Exception{
String input = null;
Scanner sc = new Scanner(new File(filePath));
StringBuffer sb = new StringBuffer();
while (sc.hasNextLine()) {
input = sc.nextLine();
sb.append(input);
}
return sb.toString();
}
public static void main(String args[]) throws FileNotFoundException {
String filePath = "D://sample.txt";
String result = fileToString(filePath);
System.out.println("Contents of the file: "+result);
//Replacing the word with desired one
result = result.replaceAll("\bTutorialspoint\b", "");
//Rewriting the contents of the file
PrintWriter writer = new PrintWriter(new File(filePath));
writer.append(result);
writer.flush();
System.out.println("Contents of the file after replacing the desired word:");
System.out.println(fileToString(filePath));
}
}Output
Contents of the file: Hello how are you welcome to Tutorialspoint Contents of the file after replacing the desired word: Hello how are you welcome to
Updated on: 10-Oct-2019
5K+ Views
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