Find a line in a file and remove it

by

This solution may not be optimal or pretty, but it works. It reads in an input file line by line, writing each line out to a temporary output file. Whenever it encounters a line that matches what you are looking for, it skips writing that one out. It then renames the output file. I have omitted error handling, closing of readers/writers, etc. from the example. I also assume there is no leading or trailing whitespace in the line you are looking for. Change the code around trim() as needed so you can find a match.

File inputFile = new File("myFile.txt");
File tempFile = new File("myTempFile.txt");

BufferedReader reader = new BufferedReader(new FileReader(inputFile));
BufferedWriter writer = new BufferedWriter(new FileWriter(tempFile));

String lineToRemove = "bbb";
String currentLine;

while((currentLine = reader.readLine()) != null) {
    // trim newline when comparing with lineToRemove
    String trimmedLine = currentLine.trim();
    if(trimmedLine.equals(lineToRemove)) continue;
    writer.write(currentLine + System.getProperty("line.separator"));
}
writer.close(); 
reader.close(); 
boolean successful = tempFile.renameTo(inputFile);

More Related Contents:

  1. Reading a resource file from within jar
  2. Standard concise way to copy a file in Java?
  3. Recursively list files in Java
  4. How to find files that match a wildcard string in Java?
  5. File changed listener in Java
  6. File loading by getClass().getResource()
  7. Read large files in Java
  8. Move / Copy File Operations in Java
  9. What is simplest way to read a file into String? [duplicate]
  10. How does Java resolve a relative path in new File()?
  11. Inserting text into an existing file via Java
  12. How to Write text file Java
  13. How to get the filename without the extension in Java?
  14. Java FileOutputStream Create File if not exists
  15. Access file in jar file?
  16. Counting the number of files in a directory using Java
  17. How to copy file inside jar to outside the jar?
  18. how to write an array to a file Java
  19. Modifying existing file content in Java
  20. Watching a Directory for Changes in Java
  21. File exists and IS directory, but listFiles() returns null
  22. How can I safely encode a string in Java to use as a filename?
  23. Java BufferedReader back to the top of a text file?
  24. How do I delete files programmatically on Android?
  25. Using BufferedReader to read Text File
  26. How can I catch all exceptions thrown through reading / writing a file?
  27. Difference between java.io.PrintWriter and java.io.BufferedWriter?
  28. How to atomically rename a file in Java, even if the dest file already exists?
  29. How can I read file from classes directory in my WAR?
  30. Test if a file is an image file

Leave a Comment