How Can I Efficiently Remove Specific Lines from a Text File?

Line Removal from a File: Finding and Eliminating Precise Lines

In the pursuit of file manipulation, there may arise scenarios where specific lines need to be removed from a given text file. To address this need, we aim to find a code snippet that locates and eliminates entire lines from a file.

Consider a sample file named "myFile.txt" with the following content:

aaa
bbb
ccc
ddd

Our desired solution is a function that allows us to remove a specified line. For instance, if we call "removeLine("bbb")", the content of "myFile.txt" should be updated to:

aaa
ccc
ddd

Proposed Code Solution

This solution efficiently tracks down the line you wish to remove and rewrites the file, excluding that specific line, into a temporary file. Once the rewrite operation is complete, the original file is replaced with the temporary file.

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) {
    // Removing leading and trailing whitespace to ensure accurate line matching
    String trimmedLine = currentLine.trim();
    if(trimmedLine.equals(lineToRemove)) continue;
    writer.write(currentLine + System.getProperty("line.separator"));
}
writer.close();
reader.close();

// Renaming the temporary file to replace the original file
boolean successful = tempFile.renameTo(inputFile);

This code accomplishes the task by reading the original file line by line, writing each non-matching line to the temporary file. When a matching line is encountered, it is skipped. Once all lines have been processed, the temporary file is renamed to replace the original file.

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